Title of Invention	AN IMPROVED PROCESS FOR THE PREPARATION OF CRYSTALLINE VANADIO SIEVE ALUMINOPHOSPHATE MOLECULAR
Abstract	An improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve by mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and heating the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve.

Title of Invention

AN IMPROVED PROCESS FOR THE PREPARATION OF CRYSTALLINE VANADIO SIEVE ALUMINOPHOSPHATE MOLECULAR

Abstract

An improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve by mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and heating the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve.

Full Text	This invention relates to an improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve. More specifically, the present invention relates to a process for the synthesis of an ultra-large pore molecular sieve with VPI-5 structure. The vanadosilicate molecular sieve of this invention is useful as a catalyst for the oxidation of a wide variety of large organic molecules in the presence of both organic peroxides and HiCh. For example, it converts aliphatic hydrocarbons into the corresponding alcohols, aldehydes or ketones; aromatic compounds into phenolic derivatives and alcohols into the corresponding aldehydes or ketones. Microporous crystalline molecular sieves are special materials. They comprise a class of inorganic composites with unique properties that are related to their framework structures. The framework of a crystalline molecular sieve consists of tetrahedral atoms (T-atoms, such as Al, Si, P) that are bridged by oxygen atoms to form a three dimensional structure. These materials possess uniformly sized channels and/or cavities that have openings circumscribed by rings consisting of a number of T-atoms (tetrahedral V-rings). For example, the main channels of the zeolite ZSM-5 are encompassed by rings of 10 T-atoms (10 rings) with medium pore size of ca. 5.5A. The largest ring found in silicate based molecular sieves such as zeolites is a 12 ring. This 12 ring pore size limits the pore opening of the zeolite such as L, Y and P (which are considered as large pore materials), to less than 8A. A significant feature of the aluminosilicate zeolites is the catalytic activity exhibited by them in acid catalyzed reactions. Zeolites possess a rigid framework of croos linked SiOa and A1O4 tetrahedra containing the trivalcnt aluminium ions and non-framework charge balancing cations usually of the alkali or alkaline earth metals. The non-framework alkali metal cations can be replaced by conventional techniques of ion exchange by other cations such as NH4+, FT, transition metal and rare earth ions. By suitable selection of the cation, it is possible to vary the properties of a given aluminosilicate ; for e.g., when the cation is a proton (H+), we get a highly acidic zeolite as a solid catalyst. By means of isomorphous substitution methods, either Si or Al ions of the aluminosilicate zeolite framework can be replaced by other tri- or tetravalent ions. Methods of direct synthesis or post synthesis are well known in the prior-art for such substitutions. In general, such metallosilicate zeolite isomorphs are potential new catalytic materials when Si and Al are replaced entirely or partially. Among the various aspects of these materials, the isomorphous replacements of A13+ by other trivalent metals like Fe3+, B3+, Cr3+, Ga3+ and La3* into the tectosilicate frameworks have been extensively reported in the prior-art [European Patent, EPA 64328, Proceedings of the 5th Int. Zeo. Conf, p. 40-48, 1980; European Patent, EPA 68, 796(1983), Proceedings of the 7th Int. Zeo. Conf, p. 137-144(1986), and US Patent, U.S. 4, 280, 305]. Small amounts of tetrahedral Ti (IV) have been reported in a ZSM-5 analog, called TS-1 [M. Taramasso et al., U. S. Patent 4,410,501 (1983); G. Pergo et al., Proceedings of the 7th Int. Zeo. Conf. P. 120 (1986), EPA 132, 550 (1985)] and in ZSM-11 analog, called TS-2 [J.S. Reddy et al., Applied Catalysis, Vol. 131, P 294 (1991)]. These titanosilicates, TS-1 and TS-2 have been found to be excellent catalysts in selective oxidation reactions involving HiCh. However, the major limitation of the use of the above metal-silicates is that their pore openings are made of 10 rings or 12 rings with pore diameter between 5.5 to 7.5 A. Thus, these materials can catalytically transform only small (molecules which are smaller in the size than the pore openings). Recently a number of V-containing molecular sieves such as VS-1, VS-2 and V-ZSM-48, possessing selective oxidation properties have also been synthesized. Like the titanosilicates these have also been found to act as selective oxidation catalysts. However, these being medium pore materials, they can transform only molecules smaller, than 5.5A in diameter. Another class of molecular sieve materials are the microporous, three dimensional crystalline aluminophosphate phases (AlPO-i) having uniform pore dimensions ranging from about 3 A to about 10A and capable of making size selective separations of molecules. In 1982, Wilson and co-workers at Union Carbide announced the synthesis of a family of aluminophosphate molecular sieves [J. Am. Chem. Soc., 104 (1982) 1146-1147]. This novel family of molecular sieves has greatly expanded the compositional and structural diversity of molecular sieve materials. Since then, hundreds of aluminophosphates and heteroatom substituted aluminophosphates with more than two dozen structures have been synthesized [S. T. Wilson et al., Synthesis of AJPCvbased molecular sieves., Stud. Surf. Sci. Catal., 58 (1991) 137-151]. These aluminophosphates differ from zeolites and titano and vanadosilicates described earlier. They are made up of [A1O4] and [PO4] tetrahedral units instead of the usual [MO4] and [SiO4] units. The chemistry of aluminio-phosphates has been reviewed by J.H. Morris et al. [Chem. Soc. Rev. 6,173 (1977)]. Aluminophosphates with an A12O3 : P2Os molar ratio of 1 : 1 are the most common and have been most widely studied. Dense phase anhydrous aluminophosphates are also known. These are isoelectronic and isostructural with silica and possess structures similar to quartz (as Berlinite), tridymite and cristobalite forms possessing frameworks of alternating AlCu and PO4 tetrahedra. Isomorphous substitution of A13+ and P5+ ions by other ions such as Si4, V4+/V5f, Ti44and Co2+ etc. in the framework of microporous aluminophosphates has already been reported. Such metal substituted aluminophosphates are called metal-aluminophosphates (MeAPO's). he materials containing Si44 called silico-aluminophosphates, (SAPO's) are acidic in nature and are useful as acid catalysts. Those containing elements such as vanadium make excellent catalysts for the selective oxidation of organic compounds in the presence of peroxides such as hydrogen peroxide or organic peroxides such as tertiary butyl hydroperoxide. The synthesis of vanadium containing A1PO4-5 has been reported by E.M. Flanigen et a/.[Eur. Pat. 158, 976 (1985)], C. Montes et al.[J. Phys. Chem. 94 (1990) 6431] and S. Qiu et al. [Zeolites, 9, (1989) 440]. Similarly, the synthesis of another aluminophosphate molecular sieve containing vanadium called V-A1PO4-31 (VAPO-31) has been reported by Venkatathri el al. in The Journal of Chemical Society, Chemical Communications, p. 151, 1995. Currently,. due to a growing demand in the chemical and petrochemical industries for molecular sieves with large pores in order to catalyze reactions of larger molecules or for separation of mixtures of large molecules, synthesis of extra-large pore molecular sieves (ring size > than 12A) has generated a great interest. In 1988, VPI-5, an aluminophosphate molecular sieve containing pores comprising of 18-rings was reported [M.E. Davis et al, Nature 331 (1988) 698-699]. This extra-large pore molecular sieve VPI-5 (Virginia Polytechnic Institute number 5) possess pores larger than 12 A. in diameter. The prior-art procedure for the synthesis of VPI-5 as reported by M. Davis et al. [Stud. Surf. Sci. Catal., 49 (1989) 199-214, 60 (1991) 53-64] involves the reaction of pseudoboehmite with phosphoric acid which are used as sources of Al and P respectively at an elevated temperature around 418K for 24 hours in the presence of an organic amine. Al-isopropoxide and polyphosphoric acid as a source of Al and P respectively may also be used. Organic species used can either be secondary or tertiary amine or quaternary ammonium ions, e.g., di-n-propylamine (n-DPA), tetrabutylammonium hydroxide (TBAOH), , di-n-pentylamine (DPeA), triethanolamine, triisopropanolamine (TIPOA), cyclopentylamine and cyclohexylamine. Duncon et al.[Bull. Soc. Fr. 129 (1992) 98-110] reported an organic free synthesis of an aluminophosphate that shows the XRD pattern of VPI-5 and concluded that VPI-5 and A1PO4-H1 synthesized by D'Yvoir in 1961 [Bull. Soc. Chem. France (1961) 1762] are similar. The synthesis of VPI-5 with partial substitution by heteroatoms such as, silicon [Davis et ai, Stud. Surf. Sci., 49 (1989) 199-214, J.A. Martens el al, Stud. Surf. Sci., 69 (1991) 267-273, Cauffreiz et al., Zeolites, 12 (1992) 121-125, J.A. Martens et al, Catal. Lett. 12 (1992) 367-374, Derouane et al., Appl. Catal., 51 (1989) L13-L20], Cobalt [Davis et al., Stud. Surf. Sci., 49 (1989) 199-214] and iron [R.F. Shinde et al., J. Phys. D., 24 (1991) 1486-1488] has been reported. The amount of Si incorporated in the VPI-5 material was very small as compared to the amount substituted in aluminophosphates molecular sieves such as Si-AlPO4-5 (SAPO-5). [J.A. Martens et al.. Stud. Surf. Sci., 37 (1988) 97-104] and Si-AlPO4-37 ( SAPO-37) [L. Sierra de Saldrriaga elal, J. Am. Chem. Soc. 109 (1987) 2686-2691]. It was found during the course of our research activity on aluminophosphate molecular sieves, that it is possible to substitute vanadium ions in the VPI-5 lattice and the vanadium containing VPI-5 analog makes an excellent catalyst for the selective oxidation of large organic molecules such as those containing two or three fused benzene rings, the oxidation of such large molecules not being feasible using the prior-art MeAPO4 molecular sieves containing 10 membered ring or 12 membered ring pore openings. Accordingly, the present invention provides an improved process ror the preparation of crystalline vanadoaluminophosphaie molecular sieve of the chemica/fewftttla where R is an organic amine selected from di-n-butylamine (n-DBA) or tetrabutylammonium hydroxide (TBAOH) or a mixture of triisopropanolamine and tetramethylammonium hydroxide (T1POA +• TMAOH) or a mixture of di-n-butylamine and tetramethylammonium hydroxide (n-DBA + TMAOH) and x is between 0.5-1.5, m is in the range of 0.0005-0.04. y is in the range 0.6-1.4 and Z is in the range 30-70 which comprises mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and heating the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve. In an embodiment of the present invention, the catalyst composite material produced has the chemical composition in terms of the mole ratios of oxides as follows : (Formula Removed) where y is between 4). 9- 1.1, x is between 0.5-1.5, m is in the range of 0.0016-0.ti2 and / is between 26=66. which comprises mixing aqueous solution of the sources of aluminium, phosphorous or organic template ( R ) in the molar composition in terms of mole ratios of oxides as under : 0.8-1.3 R : A12O, : 0.001-0.05 VO2 : 0.9.1 P2()5 : 20-60 H2O and mixing and digesting the resultant gel at room temperature in the range of 135-15()°C for 5-100 hours, filtering, washing and drying the composite material at room temperature for about 40 hours, thereafter calcining the same in vacuum at a temperature in the range of 150-350"C and converting the vanadoaluminophosphate into the dehydrated form. The source of aluminium in the reaction mixture used in the preparation of the material of the present invention can be pseudobochmite, aluminium isopropoxide and aluminium hydroxide. The preferred source of aluminium is pseudoboehmite sold under the trade name, Catapal B. The source of phosphorous in the reaction mixture used in the preparation of aluminophosphate of this invention can be orthophosphoric acid or polyphosphoric acid, the preferred source being phosphorous is orthophosphoric acid. The source of vadadium is vanadyl sulphate trihydrate, vanadium pentaoxide or ammonium metavanadate preferably vanadyl sulphate trihydrate. The vanadoaluminophosphate molecular sieve of the present invention can be prepared by mixing in any order the source of aluminium, phosphorous, vanadium, di-n-butylamine (n- OBA) or tetrabutylammonium hydroxide (TBAOH) or a mixture of triisopropanolamine and tertamethylammonium hydroxide (T1POA ^ TMAOH) or a mixture of di-n-butylamine and tetramethylammonium hydroxide (n-DBA + TMAOH) and water. The resulting mixture is then digested at room temperature for 5-25 hours and heated in an autoclave and maintained at a temperature from 130-150"C for a sufficient period to crystallize the desired material. After crystallization is over, the contents of the autoclave are quenched in cold water, filtered and washed thoroughly by hot deionized water and dried at room temperature overnight. In order to improve the catalytic properties of the material, it is desirable to convert the V4 ions into \° ions by treating two times with dilute aqueous hydrogen peroxide (H2O2 1:10 wt.%). washing well with water and dehydrating slowly by evacuating at 623K for 6 to 12 hours. Prior to the above oxidation treatment, it may be desirable to remove any occluded vanadium species from the sample by washing it with a 1 M solution of ammonium acetate at room temperature for 6 hours, filtering and washing thoroughly with deionized water. The dehydrated catalyst after oxidation with H2O2, makes an excellent selective oxidation catalyst. Even though the catalyst composite material thus obtained may be directly used as a catalyst, it is desirable in many large scale applications to enhance its mechanical strength and handling propereties by mixing it with a suitable binder material and converting into a suitable shape such as cylindrical extrudates, spheres, etc. Examples of suitable materials which impart improved mechanical properties of the catalyst material of this invention include acetic acid, stearic acid, silica, alumina, silica-alumina, clay minerals such as bentonite, kaolinite and kiesulghur and mixtures thereof. The structure of the freshly prepared vanadoaluminophosphate molecular sieves synthesizd by the process of the present invention can be characterized by different techniques. The x-ray diffraction pattern is set forth as shown in table 1 and the framework infra-red spectrum is set forth as shown in table 2. Other minor variations can occur depending on the P : V ratios of the particular sample. The vanadoaluminophosphate of the present invention is seen to have an x-ray diffraction pattern similar to that of VPI-5 molecular sieve. The novel vanadoaluminophosphate catalyst composite material prepared by the process of this invention has molecular sieve properties analogous to other known molecular sieves. Thus, the vanadoaluminophosphate may be characterized by its adsorption capacities for molecules of various sizes. Typical results are shown in table 3. The large uptakes of HjO, n-hexane and triisopropylbenzene indicates that the vanadoaluminophosphate has ultra; large pore voids. . Table 3 : Equilibrium adsorption capacity at p/po = 0.5 and 25°C. (Table Removed) = Leonard Jones Kinetic Diameter ** = V-VPI-5 sample (NH4OAc treated and H2O2 treated) with the chemical compositioi in terms of mole ratio of oxide as 1 A12O3 : 0.98 P2O5 : 0.007 VO2 It is understood that x-ray diffraction, infra-red framework vibration frequencies and adsorption capacity are characteristics of all the species of vanadoaluminophosphate composition. The process of the present invention will be further described with reference to the followingexamples which are for illustrative purposes only and are not to be construed as limitations. Example 1 This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using tetrabutylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was (Formula Removed) 8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 6.3 g. water was added slowly with stirring to the alumina slurry. 1.042 g., trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40 wt% solution) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1. The chemical composition of the solid material in terms of mole ratio of oxide was found to be 1 A12O3 : 0.99P2O5 : 0.008 VO2: 3.5 H2O / Example 2 This process illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using di-n-butyl amine as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was (Formula Removed) 8.4 g. of pseudoboehmite (Catapal B, 73% AbOj, Vista Chemicals) was slurried in 22.50 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 22.87 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 7.82 g. di-n-butyl amine (Riedel-dettaen 99%) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1. The chemical composition of the solid material in terms of mole ratio of oxide was found to be (Formula Removed) Example 3 This synthesis process describes the synthesis of vanadium containing VPI-5 (V-PI-5) using a mixture of triisopropanolamine and tetramethylammonium hydrioxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was (Formula Removed) 8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 5.89 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 12.0802 g. triisopropanolamine (Aldrich 99%) was dissolved in 23.35 g. water and 0.5469 g. tetramethylammonium hydroxide (Aldrich, 25% solution) was mixed with it and added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be (Formula Removed) Example 4 This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using a mixture of tetrabutylammonium hydroxide and tetramethyl ammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was (Formula Removed) 8.4 g. of pseudoboehmite (Catapal B, 73% A12O3> Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 6.3 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above AlPCU gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40 wt% solution) was mixed with 0.547 g. tetramethylammonium hydroxide (Aldrich, 25% solution) and added to the aged AIPO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be (Formula Removed) Example 5 This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using tetrabutylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was (Formula Removed) 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) was diluted in 45.37 g. water. 8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was added to the diluted phosphoric acid. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40 wt% solution) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be (Formula Removed) Example-6 This process illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using a mixture of di-n-butyl amine and tetramethylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was 1 A12O3 : 1 P2O5 : x VO2 : 1 n-DBA : 0.025 TMAOH : 50 H2O, where x 8.4 g. of pseudoboehmite (Catapal B, 73% A^Os, Vista Chemicals) was slurried in 22.5 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 22.87 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 7.82 g. di-n-butyl amine (Riedel-dettaen 99%) was mixed with 0.547 g. tetramethylammonium hydroxide and added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried a; room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be (Formula Removed) Example 7 This example describes in details the conversion of V4+ ions in the as-synthesized vanadium containing VPI-5 (V-VPI-5) into Vs+ ions. The vanadium containing aluminophosphate V- VPI-5 were prepared according to the procedure described in the example 1 of this patent application with different vanadium contents (V-VPI-5(1), V-VPI-5(2), V-VP"l-5(3) and V- VPI-5(4) (Table 4) using tetrabutyiamtnonium hydroxide as an organic agent. They were then soaked once in an 1 M ammonium acetate solution for 6 hours at room temperature, filtered, washed well with deionized water and dried at room temperature. They were then treated two times with dilute hydrogen peroxide (H2O2, 1:10 wt.%) to convert V4+ ions into V5* ions, filtered, washed with water and dehydrated slowly at 623K in high vacuum (10~4 Torr) overnight. The V4+ and V5^ contents in the as-synthesized, NtLiOAc washed and H2O2 treated samples were estimated by chemical analysis, atomic absorption spectroscopy, inductively coupled plasma analysis and permanganometric titrations (Table Table 4 : Chemical composition of V-VPI-5 samples (Table Removed) "The numbers in brackets refer to the % of V*f and V5+ in the samples. Example 8 In this example, the catalytic activity of these novel V-VPI-5 samples in an oxidation reaction is demonstrated. The hydroxylation of phenol using H2O2 as the oxidant in the presence of V-VPI-5 synthesized by the procedure described in this invention with different vanadium content (V-VPI-5(1), V-VPI-5(2), V-VPI-5(3) and V-VPI-5(4)) and treated with H2O2 as described in the example 7 is described. The catalytic runs were carried out in a 100 ml two-necked round bottom flask fitted with a magnetic stirrer, a condenser and a septum. The temperature of the reaction vessel was maintained using an oil bath. In a standard run, 1 g. phenol, 10 g. water and 100 mg. of the catalyst were placed in the round bottom flask. After the required temperature of 353K was attained, 0.5 ml (25% aqueous solution) of H2O2was added through a syringe. The product was taken out periodically for analysis in a capillary GC. The composition of the reaction products under the reaction conditions are given in Table 5. For comparison, the catalytic behaviour of a V-impregnated VPI-5 is included in the Table 5. V-impregnated VPI-5 is almost inactive in this reaction. Under similar conditions, the presently described V-VPI-5 samples obtained by the process of the present invention are found to be more active in this reaction. Table 5 : Ilydroxylation of phenol" (Table Removed) "Reaction conditions : Catalyst = 100 mg, Solvent(water) = 10 g, Phenol/H2O2 = 3, Temp. = 353K, Reaction time 24 h, Substrate = Ig. BQ, benzoquinone; CAT, catechol; HQ, hydroquinone. Example 9 In this example, the catalytic activity of these novel V-VPI-5 samples with different vanadium contents synthesized by the process of the present invention and treated with H2O2 as described in the example 7 in the oxidation of a large size organic molecule, 2-methyl naphthalene using both HzOa and tert. butyl hydroperoxide (TBHP) as oxidants is described. The catalytic runs were carried out in a 100 ml two-necked round bottom flask fitted with a magnetic stirrer, a condenser and a septum. The temperature of the reaction vessel was maintained using an oil bath. In a standard run, 1 g. 2-methyl naphthalene, 10 g. acetonitrile and 100 mg. of the catalyst were placed in the round bottom flask. After the required temperature of 353K was attained, 0.5 ml (70% aqueous solution) of TBHP was added through a syringe. The product was taken out periodically for analysis in a capillary GC. Details of the conversion of 2-methyl naphthalene to products like 2-naphthaldehyde, 2-naphthalene methanol and others under the reaction conditions are given in Table 6. For comparison, the catalytic behaviour of a V-impregnated VPI-5 is also included in the Table 6. V-impregnated VPI-5 sample is found to possess very little activity under similar conditions, the presently described V-VPI-5 samples in the present invention are found to be more active in this reaction confirming that the activity of V-VPI-5 samples arises from V-ions incorporated in the framework. The oxidation of 2-methyl naphthalene produces more side chain products. In general, medium pore vanado and titanosilicates such as VS-1 or TS-1 can not oxidize molecules such as 2-methyl naphthalene due to pore size restrictions. Besides, they can not utilize TBHP as an oxidant due to its large size and spatial restrictions inside the pores. V-VPI-5 is able to oxidize the large molecule, 2-methyl naphthalene, it is also able to use TBHP as the oxidant. The oxidation of such large molecules using TBHP is not possible with the presently known vanadosilicates and vanadoaluminophosphates such as VS-1, VS-2, VAPO-5 or VAPO-31. Table 6 : Oxidation of 2-mcthyl naphthalene over V-VPI-5" (Table Removed) 'Reaction conditions : Catalyst = 100 mg, Solvent(acetonitrile = lOg, Substrate/TBHP(mol) = 2, Temp. = 353K. Reaction time = 24 h, Substrate = 1 g. 'Mostly ring hydroxylation products. CH2O2 used as oxidant; reaction conditions same as in the case of TBHP runs expt., substrate/H2O2 (mole) = 2. We Claims 1.. An improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve of the chemical compasition having formula XR: A1/2O3 MVO2:YP2OS:ZH R is an organic amine selected from - di-n-butylamine (n-DBA) or tetrabutylammonium hydroxide (TBAOH) or a mixture of triisopropanolamine and tetramethylammonium hydroxide (TIPOA + TMAOH) or a mixture of di-n-butylamine and tetramethylammonium hydroxide (n-DBA > TMAOH) and x is between 0.5-1.5, m is in the range of 0.0005-0.04, y is in the range 0.6-1.4 and Z is in the ivnge 30-70 which comprises mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and healing the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve. 2. A process as claimed in claim 1 wherein the source of aluminium is pseudoboehmiic. aluminium isopropoxide and aluminium hydroxide the preferred one being pseudoboehmite. 3. A process as claimed in claims 1-2 wherein the source of phosphorous is orthophosphoric acid or polyphosphoric acid, the preferred source being orthophosphoric acid. 4. A process as claimed in claims 1-3 wherein the source of vanadium is vanadyl sulphate trihydrate, vanadium pentoxide or ammonium metavanadate, preferably vanadyl sulphate trihydrate. 5. An improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve substantially as herein described with reference to the examples.

Full Text

This invention relates to an improved process for the preparation of crystalline vanadoaluminophosphate molecular sieve. More specifically, the present invention relates to a process for the synthesis of an ultra-large pore molecular sieve with VPI-5 structure.
The vanadosilicate molecular sieve of this invention is useful as a catalyst for the oxidation of a wide variety of large organic molecules in the presence of both organic peroxides and HiCh. For example, it converts aliphatic hydrocarbons into the corresponding alcohols, aldehydes or ketones; aromatic compounds into phenolic derivatives and alcohols into the corresponding aldehydes or ketones.
Microporous crystalline molecular sieves are special materials. They comprise a class of inorganic composites with unique properties that are related to their framework structures. The framework of a crystalline molecular sieve consists of tetrahedral atoms (T-atoms, such as Al, Si, P) that are bridged by oxygen atoms to form a three dimensional structure. These materials possess uniformly sized channels and/or cavities that have openings circumscribed by rings consisting of a number of T-atoms (tetrahedral V-rings). For example, the main channels of the zeolite ZSM-5 are encompassed by rings of 10 T-atoms (10 rings) with medium pore size of ca. 5.5A. The largest ring found in silicate based molecular sieves such as zeolites is a 12 ring. This 12 ring pore size limits the pore opening of the zeolite such as L, Y and P (which are considered as large pore materials), to less than 8A.
A significant feature of the aluminosilicate zeolites is the catalytic activity exhibited by them in acid catalyzed reactions. Zeolites possess a rigid framework of croos linked SiOa and A1O4 tetrahedra containing the trivalcnt aluminium ions and non-framework charge balancing cations usually of the alkali or alkaline earth metals. The non-framework alkali metal cations can be replaced by conventional techniques of ion exchange by other cations
such as NH4+, FT, transition metal and rare earth ions. By suitable selection of the cation, it is possible to vary the properties of a given aluminosilicate ; for e.g., when the cation is a proton (H+), we get a highly acidic zeolite as a solid catalyst.
By means of isomorphous substitution methods, either Si or Al ions of the aluminosilicate zeolite framework can be replaced by other tri- or tetravalent ions. Methods of direct synthesis or post synthesis are well known in the prior-art for such substitutions. In general, such metallosilicate zeolite isomorphs are potential new catalytic materials when Si and Al are replaced entirely or partially. Among the various aspects of these materials, the isomorphous replacements of A13+ by other trivalent metals like Fe3+, B3+, Cr3+, Ga3+ and La3* into the tectosilicate frameworks have been extensively reported in the prior-art [European Patent, EPA 64328, Proceedings of the 5th Int. Zeo. Conf, p. 40-48, 1980; European Patent, EPA 68, 796(1983), Proceedings of the 7th Int. Zeo. Conf, p. 137-144(1986), and US Patent, U.S. 4, 280, 305].
Small amounts of tetrahedral Ti (IV) have been reported in a ZSM-5 analog, called TS-1 [M. Taramasso et al., U. S. Patent 4,410,501 (1983); G. Pergo et al., Proceedings of the 7th Int. Zeo. Conf. P. 120 (1986), EPA 132, 550 (1985)] and in ZSM-11 analog, called TS-2 [J.S. Reddy et al., Applied Catalysis, Vol. 131, P 294 (1991)]. These titanosilicates, TS-1 and TS-2 have been found to be excellent catalysts in selective oxidation reactions involving HiCh. However, the major limitation of the use of the above metal-silicates is that their pore openings are made of 10 rings or 12 rings with pore diameter between 5.5 to 7.5 A. Thus, these materials can catalytically transform only small (molecules which are smaller in the size than the pore openings).
Recently a number of V-containing molecular sieves such as VS-1, VS-2 and V-ZSM-48, possessing selective oxidation properties have also been synthesized. Like the
titanosilicates these have also been found to act as selective oxidation catalysts. However, these being medium pore materials, they can transform only molecules smaller, than 5.5A in diameter.
Another class of molecular sieve materials are the microporous, three dimensional crystalline aluminophosphate phases (AlPO-i) having uniform pore dimensions ranging from about 3 A to about 10A and capable of making size selective separations of molecules. In 1982, Wilson and co-workers at Union Carbide announced the synthesis of a family of aluminophosphate molecular sieves [J. Am. Chem. Soc., 104 (1982) 1146-1147]. This novel family of molecular sieves has greatly expanded the compositional and structural diversity of molecular sieve materials. Since then, hundreds of aluminophosphates and heteroatom substituted aluminophosphates with more than two dozen structures have been synthesized [S. T. Wilson et al., Synthesis of AJPCvbased molecular sieves., Stud. Surf. Sci. Catal., 58 (1991) 137-151]. These aluminophosphates differ from zeolites and titano and vanadosilicates described earlier. They are made up of [A1O4] and [PO4] tetrahedral units instead of the usual [MO4] and [SiO4] units. The chemistry of aluminio-phosphates has been reviewed by J.H. Morris et al. [Chem. Soc. Rev. 6,173 (1977)]. Aluminophosphates with an A12O3 : P2Os molar ratio of 1 : 1 are the most common and have been most widely studied. Dense phase anhydrous aluminophosphates are also known. These are isoelectronic and isostructural with silica and possess structures similar to quartz (as Berlinite), tridymite and cristobalite forms possessing frameworks of alternating AlCu and PO4 tetrahedra.
Isomorphous substitution of A13+ and P5+ ions by other ions such as Si4*, V4+/V5f, Ti44and Co2+ etc. in the framework of microporous aluminophosphates has already been reported. Such metal substituted aluminophosphates are called metal-aluminophosphates (MeAPO's).
he materials containing Si44 called silico-aluminophosphates, (SAPO's) are acidic in nature and are useful as acid catalysts. Those containing elements such as vanadium make excellent catalysts for the selective oxidation of organic compounds in the presence of peroxides such as hydrogen peroxide or organic peroxides such as tertiary butyl hydroperoxide. The synthesis of vanadium containing A1PO4-5 has been reported by E.M. Flanigen et a/.[Eur. Pat. 158, 976 (1985)], C. Montes et al.[J. Phys. Chem. 94 (1990) 6431] and S. Qiu et al. [Zeolites, 9, (1989) 440]. Similarly, the synthesis of another aluminophosphate molecular sieve containing vanadium called V-A1PO4-31 (VAPO-31) has been reported by Venkatathri el al. in The Journal of Chemical Society, Chemical Communications, p. 151, 1995.
Currently,. due to a growing demand in the chemical and petrochemical industries for molecular sieves with large pores in order to catalyze reactions of larger molecules or for separation of mixtures of large molecules, synthesis of extra-large pore molecular sieves (ring size > than 12A) has generated a great interest.
In 1988, VPI-5, an aluminophosphate molecular sieve containing pores comprising of 18-rings was reported [M.E. Davis et al, Nature 331 (1988) 698-699]. This extra-large pore molecular sieve VPI-5 (Virginia Polytechnic Institute number 5) possess pores larger than 12 A. in diameter.
The prior-art procedure for the synthesis of VPI-5 as reported by M. Davis et al. [Stud. Surf. Sci. Catal., 49 (1989) 199-214, 60 (1991) 53-64] involves the reaction of pseudoboehmite with phosphoric acid which are used as sources of Al and P respectively at an elevated temperature around 418K for 24 hours in the presence of an organic amine. Al-isopropoxide and polyphosphoric acid as a source of Al and P respectively may also be used. Organic species used can either be secondary or tertiary amine or quaternary
ammonium ions, e.g., di-n-propylamine (n-DPA), tetrabutylammonium hydroxide (TBAOH), , di-n-pentylamine (DPeA), triethanolamine, triisopropanolamine (TIPOA), cyclopentylamine and cyclohexylamine. Duncon et al.[Bull. Soc. Fr. 129 (1992) 98-110] reported an organic free synthesis of an aluminophosphate that shows the XRD pattern of VPI-5 and concluded that VPI-5 and A1PO4-H1 synthesized by D'Yvoir in 1961 [Bull. Soc. Chem. France (1961) 1762] are similar.
The synthesis of VPI-5 with partial substitution by heteroatoms such as, silicon [Davis et ai, Stud. Surf. Sci., 49 (1989) 199-214, J.A. Martens el al, Stud. Surf. Sci., 69 (1991) 267-273, Cauffreiz et al., Zeolites, 12 (1992) 121-125, J.A. Martens et al, Catal. Lett. 12 (1992) 367-374, Derouane et al., Appl. Catal., 51 (1989) L13-L20], Cobalt [Davis et al., Stud. Surf. Sci., 49 (1989) 199-214] and iron [R.F. Shinde et al., J. Phys. D., 24 (1991) 1486-1488] has been reported. The amount of Si incorporated in the VPI-5 material was very small as compared to the amount substituted in aluminophosphates molecular sieves such as Si-AlPO4-5 (SAPO-5). [J.A. Martens et al.. Stud. Surf. Sci., 37 (1988) 97-104] and Si-AlPO4-37 ( SAPO-37) [L. Sierra de Saldrriaga elal, J. Am. Chem. Soc. 109 (1987) 2686-2691].
It was found during the course of our research activity on aluminophosphate molecular sieves, that it is possible to substitute vanadium ions in the VPI-5 lattice and the vanadium containing VPI-5 analog makes an excellent catalyst for the selective oxidation of large organic molecules such as those containing two or three fused benzene rings, the oxidation of such large molecules not being feasible using the prior-art MeAPO4 molecular sieves containing 10 membered ring or 12 membered ring pore openings.
Accordingly, the present invention provides an improved process ror the preparation
of crystalline vanadoaluminophosphaie molecular sieve of the chemica/fewftttla where R is
an organic amine selected from di-n-butylamine (n-DBA) or tetrabutylammonium hydroxide
(TBAOH) or a mixture of triisopropanolamine and tetramethylammonium hydroxide (T1POA +• TMAOH) or a mixture of di-n-butylamine and tetramethylammonium hydroxide (n-DBA + TMAOH) and x is between 0.5-1.5, m is in the range of 0.0005-0.04. y is in the range 0.6-1.4 and Z is in the range 30-70 which comprises mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and heating the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve.
In an embodiment of the present invention, the catalyst composite material produced has the chemical composition in terms of the mole ratios of oxides as follows :
(Formula Removed)
where y is between 4). 9- 1.1, x is between 0.5-1.5, m is in the range of 0.0016-0.ti2 and / is
between 26=66. which comprises mixing aqueous solution of the sources of aluminium, phosphorous or organic template ( R ) in the molar composition in terms of mole ratios of oxides as under :
0.8-1.3 R : A12O, : 0.001-0.05 VO2 : 0.9.1 P2()5 : 20-60 H2O
and mixing and digesting the resultant gel at room temperature in the range of 135-15()°C for 5-100 hours, filtering, washing and drying the composite material at room temperature for about 40 hours, thereafter calcining the same in vacuum at a temperature in the range of 150-350"C and converting the vanadoaluminophosphate into the dehydrated form.
The source of aluminium in the reaction mixture used in the preparation of the material of the present invention can be pseudobochmite, aluminium isopropoxide and aluminium hydroxide. The preferred source of aluminium is pseudoboehmite sold under the trade name, Catapal B. The source of phosphorous in the reaction mixture used in the preparation of aluminophosphate of this invention can be orthophosphoric acid or polyphosphoric acid, the preferred source being phosphorous is orthophosphoric acid. The source of vadadium is vanadyl sulphate trihydrate, vanadium pentaoxide or ammonium metavanadate preferably vanadyl sulphate trihydrate.
The vanadoaluminophosphate molecular sieve of the present invention can be prepared
by mixing in any order the source of aluminium, phosphorous, vanadium, di-n-butylamine (n-
OBA) or tetrabutylammonium hydroxide (TBAOH) or a mixture of triisopropanolamine and
tertamethylammonium hydroxide (T1POA ^ TMAOH) or a mixture of di-n-butylamine and
tetramethylammonium hydroxide (n-DBA + TMAOH) and water. The resulting mixture is then
digested at room temperature for 5-25 hours and heated in an autoclave and maintained at a
temperature from 130-150"C for a sufficient period to crystallize the desired material. After
crystallization is over, the contents of the autoclave are quenched in cold water, filtered and
washed thoroughly by hot deionized water and dried at room temperature overnight. In order to
improve the catalytic properties of the material, it is desirable to convert the V4 ions into \°
ions by treating two times with dilute aqueous hydrogen peroxide (H2O2 1:10 wt.%). washing
well with water and dehydrating slowly by evacuating at 623K for 6
to 12 hours. Prior to the above oxidation treatment, it may be
desirable to remove any occluded vanadium species from the sample by washing it with a 1 M solution of ammonium acetate at room temperature for 6 hours, filtering and washing thoroughly with deionized water. The dehydrated catalyst after oxidation with H2O2, makes an excellent selective oxidation catalyst.
Even though the catalyst composite material thus obtained may be directly used as a catalyst, it is desirable in many large scale applications to enhance its mechanical strength and handling propereties by mixing it with a suitable binder material and converting into a suitable shape such as cylindrical extrudates, spheres, etc. Examples of suitable materials which impart improved mechanical properties of the catalyst material of this invention include acetic acid, stearic acid, silica, alumina, silica-alumina, clay minerals such as bentonite, kaolinite and kiesulghur and mixtures thereof.
The structure of the freshly prepared vanadoaluminophosphate molecular sieves synthesizd by the process of the present invention can be characterized by different techniques. The x-ray diffraction pattern is set forth as shown in table 1 and the framework infra-red spectrum is set forth as shown in table 2. Other minor variations can occur depending on the P : V ratios of the particular sample. The vanadoaluminophosphate of the present invention is seen to have an x-ray diffraction pattern similar to that of VPI-5 molecular sieve. The novel vanadoaluminophosphate catalyst composite material prepared by the process of this invention has molecular sieve properties analogous to other known molecular sieves. Thus, the vanadoaluminophosphate may be characterized by its adsorption capacities for molecules of various sizes. Typical results are shown in table 3. The large uptakes of HjO, n-hexane and triisopropylbenzene indicates that the vanadoaluminophosphate has ultra; large pore voids. .
Table 3 : Equilibrium adsorption capacity at p/po = 0.5 and 25°C.
(Table Removed)

* = Leonard Jones Kinetic Diameter
** = V-VPI-5 sample (NH4OAc treated and H2O2 treated) with the chemical compositioi
in terms of mole ratio of oxide as 1 A12O3 : 0.98 P2O5 : 0.007 VO2
It is understood that x-ray diffraction, infra-red framework vibration frequencies and
adsorption capacity are characteristics of all the species of vanadoaluminophosphate
composition.
The process of the present invention will be further described with reference to the
followingexamples which are for illustrative purposes only and are not to be construed as
limitations.
Example 1
This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using tetrabutylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
(Formula Removed)
8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 6.3 g. water was added slowly with stirring to the alumina slurry. 1.042 g., trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40

wt% solution) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
1 A12O3 : 0.99P2O5 : 0.008 VO2: 3.5 H2O
/
Example 2
This process illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using di-n-butyl amine as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
(Formula Removed)
8.4 g. of pseudoboehmite (Catapal B, 73% AbOj, Vista Chemicals) was slurried in 22.50 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 22.87 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 7.82 g. di-n-butyl amine (Riedel-dettaen 99%) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
(Formula Removed)
Example 3
This synthesis process describes the synthesis of vanadium containing VPI-5 (V-PI-5) using a mixture of triisopropanolamine and tetramethylammonium hydrioxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
(Formula Removed)

8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 5.89 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 12.0802 g. triisopropanolamine (Aldrich 99%) was dissolved in 23.35 g. water and 0.5469 g. tetramethylammonium hydroxide (Aldrich, 25% solution) was mixed with it and added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
(Formula Removed)
Example 4
This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using a mixture of tetrabutylammonium hydroxide and tetramethyl ammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
(Formula Removed)
8.4 g. of pseudoboehmite (Catapal B, 73% A12O3> Vista Chemicals) was slurried in 16.0 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 6.3 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above AlPCU gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40 wt% solution) was mixed with 0.547 g. tetramethylammonium hydroxide (Aldrich, 25% solution) and added to the aged AIPO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
(Formula Removed)
Example 5
This example illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using tetrabutylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
(Formula Removed)
13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) was diluted in 45.37 g. water. 8.4 g. of pseudoboehmite (Catapal B, 73% A12O3, Vista Chemicals) was added to the diluted phosphoric acid. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in
4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 38.922 g. tetrabutylammonium hydroxide (Aldrich, 40 wt% solution) was added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot water and dried at room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
(Formula Removed)
Example-6
This process illustrates the synthesis of vanadium containing VPI-5 (V-VPI-5) using a mixture of di-n-butyl amine and tetramethylammonium hydroxide as an organic agent. The composition of the hydrothermal gel in terms of moles of oxides was
1 A12O3 : 1 P2O5 : x VO2 : 1 n-DBA : 0.025 TMAOH : 50 H2O, where x 8.4 g. of pseudoboehmite (Catapal B, 73% A^Os, Vista Chemicals) was slurried in 22.5 g. water. 13.86 g. orthophosphoric acid (S. D. Fine chemicals 85% solution) diluted in 22.87 g. water was added slowly with stirring to the alumina slurry. 1.042 g. vanadyl sulphate trihydrate (Aldrich, 99%) dissolved in 4.0 g. water was added to the above A1PO4 gel and aged at 298K for 24 hours. Then 7.82 g. di-n-butyl amine (Riedel-dettaen 99%) was mixed with 0.547 g. tetramethylammonium hydroxide and added to the aged A1PO4 gel and stirred for one hour. The reaction mixture was transferred to the stainless steel autoclave and crystallized at 418K for 24 hours. The crystalline material obtained was washed with hot
water and dried a; room temperature. The V-VPI-5 sample was identified by XRD, and IR spectra as shown in Table 1 and 2 respectively. The chemical composition of the solid material in terms of mole ratio of oxide was found to be
(Formula Removed)
Example 7
This example describes in details the conversion of V4+ ions in the as-synthesized vanadium
containing VPI-5 (V-VPI-5) into Vs+ ions. The vanadium containing aluminophosphate V-
VPI-5 were prepared according to the procedure described in the example 1 of this patent
application with different vanadium contents (V-VPI-5(1), V-VPI-5(2), V-VP"l-5(3) and V-
VPI-5(4) (Table 4) using tetrabutyiamtnonium hydroxide as an organic agent. They were
then soaked once in an 1 M ammonium acetate solution for 6 hours at room temperature,
filtered, washed well with deionized water and dried at room temperature. They were then
treated two times with dilute hydrogen peroxide (H2O2, 1:10 wt.%) to convert V4+ ions
into V5* ions, filtered, washed with water and dehydrated slowly at 623K in high vacuum
(10~4 Torr) overnight. The V4+ and V5^ contents in the as-synthesized, NtLiOAc washed
and H2O2 treated samples were estimated by chemical analysis, atomic absorption spectroscopy, inductively coupled plasma analysis and permanganometric titrations (Table
Table 4 : Chemical composition of V-VPI-5 samples

(Table Removed)
"The numbers in brackets refer to the % of V*f and V5+ in the samples.
Example 8
In this example, the catalytic activity of these novel V-VPI-5 samples in an oxidation reaction is demonstrated. The hydroxylation of phenol using H2O2 as the oxidant in the presence of V-VPI-5 synthesized by the procedure described in this invention with different vanadium content (V-VPI-5(1), V-VPI-5(2), V-VPI-5(3) and V-VPI-5(4)) and treated with H2O2 as described in the example 7 is described. The catalytic runs were carried out in a 100 ml two-necked round bottom flask fitted with a magnetic stirrer, a condenser and a septum. The temperature of the reaction vessel was maintained using an oil bath. In a standard run, 1 g. phenol, 10 g. water and 100 mg. of the catalyst were placed in the round bottom flask. After the required temperature of 353K was attained, 0.5 ml (25% aqueous solution) of H2O2was added through a syringe. The product was taken out periodically for analysis in a capillary GC. The composition of the reaction products under the reaction conditions are given in Table 5. For comparison, the catalytic behaviour of a V-impregnated VPI-5 is included in the Table 5. V-impregnated VPI-5 is almost inactive in this reaction. Under similar conditions, the presently described V-VPI-5 samples obtained by the process of the present invention are found to be more active in this reaction.
Table 5 : Ilydroxylation of phenol"

(Table Removed)
"Reaction conditions : Catalyst = 100 mg, Solvent(water) = 10 g, Phenol/H2O2 = 3, Temp. = 353K, Reaction time 24 h, Substrate = Ig. BQ, benzoquinone; CAT, catechol; HQ, hydroquinone.
Example 9
In this example, the catalytic activity of these novel V-VPI-5 samples with different vanadium contents synthesized by the process of the present invention and treated with H2O2 as described in the example 7 in the oxidation of a large size organic molecule, 2-methyl naphthalene using both HzOa and tert. butyl hydroperoxide (TBHP) as oxidants is described. The catalytic runs were carried out in a 100 ml two-necked round bottom flask fitted with a magnetic stirrer, a condenser and a septum. The temperature of the reaction vessel was maintained using an oil bath. In a standard run, 1 g. 2-methyl naphthalene, 10 g. acetonitrile and 100 mg. of the catalyst were placed in the round bottom flask. After the required temperature of 353K was attained, 0.5 ml (70% aqueous solution) of TBHP was added through a syringe. The product was taken out periodically for analysis in a capillary GC. Details of the conversion of 2-methyl naphthalene to products like 2-naphthaldehyde, 2-naphthalene methanol and others under the reaction conditions are given in Table 6. For comparison, the catalytic behaviour of a V-impregnated VPI-5 is also included in the Table
6. V-impregnated VPI-5 sample is found to possess very little activity under similar conditions, the presently described V-VPI-5 samples in the present invention are found to be more active in this reaction confirming that the activity of V-VPI-5 samples arises from V-ions incorporated in the framework. The oxidation of 2-methyl naphthalene produces more side chain products. In general, medium pore vanado and titanosilicates such as VS-1 or TS-1 can not oxidize molecules such as 2-methyl naphthalene due to pore size restrictions. Besides, they can not utilize TBHP as an oxidant due to its large size and spatial restrictions inside the pores. V-VPI-5 is able to oxidize the large molecule, 2-methyl naphthalene, it is also able to use TBHP as the oxidant. The oxidation of such large molecules using TBHP is not possible with the presently known vanadosilicates and vanadoaluminophosphates such as VS-1, VS-2, VAPO-5 or VAPO-31.
Table 6 : Oxidation of 2-mcthyl naphthalene over V-VPI-5"

(Table Removed)
'Reaction conditions : Catalyst = 100 mg, Solvent(acetonitrile = lOg, Substrate/TBHP(mol) = 2, Temp. = 353K. Reaction time = 24 h, Substrate = 1 g.
'Mostly ring hydroxylation products.
CH2O2 used as oxidant; reaction conditions same as in the case of TBHP runs expt.,
substrate/H2O2 (mole) = 2.

We Claims
1.. An improved process for the preparation of crystalline vanadoaluminophosphate
molecular sieve of the chemical compasition having formula XR: A1/2O3 MVO2:YP2OS:ZH
R is an organic amine selected from
-
di-n-butylamine (n-DBA) or tetrabutylammonium hydroxide (TBAOH) or a mixture of triisopropanolamine and tetramethylammonium hydroxide (TIPOA + TMAOH) or a mixture of di-n-butylamine and tetramethylammonium hydroxide (n-DBA > TMAOH) and x is between 0.5-1.5, m is in the range of 0.0005-0.04, y is in the range 0.6-1.4 and Z is in the ivnge 30-70 which comprises mixing aqueous solutions of sources of aluminium, vanadium, phosphorous and digesting the mixture at room temperature for 5-25 hours and healing the mixture in an autoclave at a temperature in the 130-150°C for a 5-100 hours to crystallize the product, filtering and washing the product thoroughly by hot deionized water and drying overnight at room temperature to obtain vanadoaluminophosphate molecular sieve.
2. A process as claimed in claim 1 wherein the source of aluminium is pseudoboehmiic.
aluminium isopropoxide and aluminium hydroxide the preferred one being
pseudoboehmite.
3. A process as claimed in claims 1-2 wherein the source of phosphorous is
orthophosphoric acid or polyphosphoric acid, the preferred source being
orthophosphoric acid.
4. A process as claimed in claims 1-3 wherein the source of vanadium is vanadyl
sulphate trihydrate, vanadium pentoxide or ammonium metavanadate, preferably
vanadyl sulphate trihydrate.
5. An improved process for the preparation of crystalline vanadoaluminophosphate
molecular sieve substantially as herein described with reference to the examples.

Documents:

1086-del-1996-abstract.pdf

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1086-del-1996-complete specification (granted).pdf

1086-del-1996-correspondence-others.pdf

1086-del-1996-correspondence-po.pdf

1086-del-1996-description (complete).pdf

1086-del-1996-form-1.pdf

1086-del-1996-form-2.pdf

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Patent Number

196838

Indian Patent Application Number

1086/DEL/1996

PG Journal Number

29/2008

Publication Date

26-Sep-2008

Grant Date

30-Mar-2007

Date of Filing

23-May-1996

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	KARUNA CHAUDHARI	NATIONAL CHEMICAL LABORATORY, PUNE, MAHARASHTRA STATE, PUNE, INDIA.
2	TAPAN KUMAR DAS	NATIONAL CHEMICAL LABORATORY, PUNE, MAHARASHTRA STATE, PUNE, INDIA.
3	ASHA JEEVAN CHANDWADKAR	NATIONAL CHEMICAL LABORATORY, PUNE, MAHARASHTRA STATE, PUNE, INDIA.
4	SUBRAMANIAN SIVASANKER	NATIONAL CHEMICAL LABORATORY, PUNE, MAHARASHTRA STATE, PUNE, INDIA.

PCT International Classification Number

C08F 4/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA