A method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture wherein a weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4 and an equivalent molar ratio of titanium-containing compound to peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt. % to about 20 wt. % water and the solubilized titanium mixture to form an addition product and drying the addition product by heating to a temperature in a range of from about 50° C. to about 150° C. and maintaining the temperature in the range of from about 50° C. to about 150° C. for a time period of from about 30 minutes to about 6 hours to form a pre-catalyst.

Methods of producing gold-palladium catalysts suitable for use in the production of vinyl acetate may include drying the catalyst after the incorporation of a promoter at higher temperatures (e.g., 160° C. or greater) to restructure the metals and/or alloys on the catalyst. The restructured catalyst advantageously has increased catalytic activity and improved stability.

A process for producing an oligomerization catalyst includes hydrothermal treatment. An oligomerization catalyst produced by the process is useful for the oligomerization of C.sub.2 to C.sub.12 olefins.

A process for producing an oligomerization catalyst includes hydrothermal treatment. An oligomerization catalyst produced by the process is useful for the oligomerization of C.sub.2 to C.sub.12 olefins.

The present invention relates to the field of isobutylene preparation. Disclosed are a catalyst and preparation method thereof, and method for preparing isobutylene by applying the same; the catalyst has a core-shell structure, the core an amorphous silica-alumina particle and/or an aggregate molding thereof, and the shell aluminum oxide comprising silicon and tin; the weight ratio of aluminum oxide comprising silicon and tin to amorphous silica-alumina is 1:60-1:3; in the aluminum oxide comprising silicon and tin, on basis of the weight of aluminum oxide comprising silicon and tin, the content of silicon is 0.5-2 wt %, and of tin is 0.2-1 wt %. The catalyst of the present invention is used to catalyze a mixture of MTBE and TBA to prepare isobutylene, enabling the MTBE cleavage reaction and TBA dehydration reactions to be conducted simultaneously to generate isobutylene, achieving higher conversion rates of TBA and MTBE, and higher selectivity for generating isobutylene.

The present invention relates to the field of isobutylene preparation. Disclosed are a catalyst and preparation method thereof, and method for preparing isobutylene by applying the same; the catalyst has a core-shell structure, the core an amorphous silica-alumina particle and/or an aggregate molding thereof, and the shell aluminum oxide comprising silicon and tin; the weight ratio of aluminum oxide comprising silicon and tin to amorphous silica-alumina is 1:60-1:3; in the aluminum oxide comprising silicon and tin, on basis of the weight of aluminum oxide comprising silicon and tin, the content of silicon is 0.5-2 wt %, and of tin is 0.2-1 wt %. The catalyst of the present invention is used to catalyze a mixture of MTBE and TBA to prepare isobutylene, enabling the MTBE cleavage reaction and TBA dehydration reactions to be conducted simultaneously to generate isobutylene, achieving higher conversion rates of TBA and MTBE, and higher selectivity for generating isobutylene.

A modified β zeolite has 0.5-15 wt % of an IVB group metal element in terms of oxide on the dry basis weight of the modified β zeolite. The number of medium strong acid centers of the modified β zeolite accounts for 30-60% of the total acid amount, the number of strong acid centers accounts for 5-25% of the total acid amount, and the ratio of B acid to L acid is 0.8 or more. The ratio of the weight content of the IVB group metal element in the modified β zeolite body phase to the weight content of the IVB group metal element on the surface is 0.1-0.8. The catalytic cracking catalyst containing the modified β zeolite has good selectivity and yield of C4 olefin.

A modified β zeolite has 0.5-15 wt % of an IVB group metal element in terms of oxide on the dry basis weight of the modified β zeolite. The number of medium strong acid centers of the modified β zeolite accounts for 30-60% of the total acid amount, the number of strong acid centers accounts for 5-25% of the total acid amount, and the ratio of B acid to L acid is 0.8 or more. The ratio of the weight content of the IVB group metal element in the modified β zeolite body phase to the weight content of the IVB group metal element on the surface is 0.1-0.8. The catalytic cracking catalyst containing the modified β zeolite has good selectivity and yield of C4 olefin.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.