Patent ID: 6638888
Filing Date: 2003-10-28
Classification: B01J,C10G

Abstract:
Mesoporous material comprising an &ggr; alumina throughout which optionally one or more oxides selected from silica, boron oxide, phosphorous oxide, the oxide of a metal of group VIII and/or VIB having general formula MOx, are uniformly dispersed, with the following molar ratios between said oxides and the alumina:SiO2/Al2O3=0-3.0 B2O3/Al2O3=0-4.0 P2O5/Al2O3=0-0.2 MOx/Al2O3=0-0.2. wherein the material has a surface area of between 260 and 700 m2/g, a pore volume of between 0.2 and 1.0 cm3/g, a monomodal pore size distribution of between 20 and 70 Ã¥, and substantially all pore diameters of between 20 and 70 Ã¥, wherein an X-ray diffraction spectrum from powders of the mesoporous material exposed to CuK&agr; radiation has in the high angular region a pattern typical or indicative of &ggr; alumina, wherein at angular values of not more than 2&thgr;=5Â°, there are (1) no coherent scattering phenomena or (2) there is an enlarged diffraction line or there is weak or diffuse scattering, and, wherein said material is prepared by a process comprising: (a) preparing a solution, in an alcohol having the formula Râ€³OH, wherein Râ€³ is a linear or branched C1-C5 group, of an aluminum alkoxide having the formula Al(OR)3, wherein R is a linear or branched C1-C5 alkyl group, and optionally of a source of one or more elements selected from silicon, boron, phosphorous, and/or a compound soluble in an alcohol environment of a metal of a group VIII; (b) subjecting the alcohol solution prepared in step (a) to hydrolysis and gelification, at a temperature of between 20 and 80Â° C., with a water solution containing a hydroxide of tetralkylammonium having the formula Râ€²4Nâ€”OH, wherein Râ€² is a linear or branched C2-C7 alkyl group, and optionally a compound of a metal of group VIB soluble in a basic environment, the quantity of the constituents of the mixture thus obtained being such as to respect the following molar ratios: H2O/Al2O3 =15-100Râ€³OH/Al2O3 =5-50 Râ€²4Nâ€”OH/Al2O3 =0.3-5SiO2/Al2O3 =0-3.0B2O3/Al2O3 =0-4.0P2O5/Al2O3 =0-0.2MOX/Al2O3 =0-0.2(c) subjecting the gel obtained in step (b) to drying and calcination.