| 摘要 |
There are provided crystalline chromosilicates, their methods of preparation, and process uses. A first crystalline chromosilicate comprises a molecular sieve material providing a specific X-ray diffraction pattern and having the following composition in terms of mole ratios of oxides: 0.9+/-0.2[WR2O+(1-W)M2/nO]:Cr2O3:YSiO2:ZH2O, wherein R is an alkyl ammonium cation, M is at least one cation having a valence of n, Y is a value within the range of about 4 to about 500, Z is a value within the range of about 0 to about 160, and W is a value that is greater than or equal to 0 and less than or equal to 1. A second crystalline chromosilicate comprises a molecular sieve material providing a specific X-ray diffraction pattern and having the following composition in terms of mole ratios of oxides: 0.9+/-0.2M2/nO :Cr2O3:YSiO2:ZH2 O, wherein M is at least one cation having a valence of n, Y is within the range of about 4 to about 500, and Z is within the range of about 0 to about 160. The first crystalline chromosilicate is a precursor of the second. There is provided also a process for the conversion of a hydrocarbon stream, which process comprises contacting said stream under hydrocarbon conversion conditions with a catalyst comprising the second crystalline chromosilicate. In addtion, there is provided a process for the isomerization of a xylene feed, which process comprises contacting said feed under isomerization conditions with a catalyst comprising the second crystalline chromosilicate.
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