A catalyst comprising palladium, a porous support comprising at least one refractory oxide selected from the group constituted by silica, alumina and silica-alumina, the palladium content in the catalyst being in the range 0.01% to 2% by weight with respect to the total catalyst weight, at least 80% by weight of the palladium being distributed in a crust at the periphery of said support, the thickness of said crust being in the range 20 to 100 m, characterized in that said support is in the form of an extrudate and in that said support comprises a specific surface area in the range 165 to 250 m.sup.2/g.

A silica particle includes a silica particle body and a titania coating layer formed on a surface of the silica particle body through a reaction of a titanium compound having a structure in which a hydrocarbon group bonds to a titanium atom through an oxygen atom. The silica particle has absorption at a wavelength of about 400 nm or more and about 800 nm or less in an ultraviolet-visible absorption spectrum.

The present invention is in the field of catalysis. More particularly, the present invention is directed to supported precious metal catalysts, preferably palladium and/or platinum metal catalysts, having a high metal loading, a high degree of dispersion and a high degree of edge-coating. The present invention is further directed to a process for producing these catalysts, as well as to the use of these catalysts in chemical reactions.

An object of the present invention is to provide ferrite particles for supporting a catalyst having a small apparent density, various properties are maintained in a controllable state and a specified volume is filled with a small weight, and a catalyst using the ferrite particles for supporting a catalyst. To achieve the object, ferrite particles for supporting a catalyst provided with an outer shell structure containing Ti oxide, a catalyst using the ferrite particles for supporting a catalyst are employed.

Disclosed are novel processes for making cyclohexanone compositions, from a mixture comprising phenol, cyclohexanone, and cyclohexylbenzene. The process includes hydrogenation of a feed stream comprising phenol, cyclohexanone, and cyclohexylbenzene. The feed stream may be subjected to one or more pre-hydrogenation treatments, such as passing through one or more sorbents, addition of basic chemical agents, and/or addition of water, so as to improve catalyst activity, minimize undesired side reactions, and/or remove catalyst poisons from the feed stream. The feed stream may be provided to a hydrogenation reaction zone in the vapor phase, with periodic alterations to hydrogenation reaction conditions such that the feed is provided in mixed liquid and vapor phase in order to carry out liquid washing of a hydrogenation catalyst bed within the hydrogenation reaction zone.

Disclosed are a method for preparing a noble metal hydrogenation catalyst comprising preparing a carrier from a molecular sieve having a 10-member ring structure and/or an amorphous porous material; preparing a noble metal impregnation solution; and preparing noble metal impregnation solutions in a concentration gradient ranging from 0.05 to 5.0 wt % with deionized water, and sequentially impregnating the carrier with the impregnation solutions from low to high concentrations during the carrier impregnation process, or preparing a noble metal impregnation solution at a low concentration ranging from 0.05 to 0.5 wt % and impregnating the carrier by gradually increasing the concentration of the noble metal impregnation solution to 2.0 to 5.0 wt % in the impregnation process, followed by homogenization, drying, and calcination, as well as a noble metal hydrogenation catalyst, use thereof, and a method for preparing lubricant base oil.

This invention relates to a novel nickel catalyst and a novel one-pot solution combustion synthesis of that catalyst for the CO.sub.2 reforming and low temperature steam reformation of methane. The novel nickel catalyst has exceptional activity for dry reforming and steam reforming of methane, and exhibits excellent resilience to deactivation due to carbon formation.

A composition containing a supported hydrogenation catalyst comprising palladium and a support, wherein the supported hydrogenation catalyst is capable of selectively hydrogenating highly unsaturated hydrocarbons to unsaturated hydrocarbons, and a dopant, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof. A method of making a selective hydrogenation catalyst by contacting a support with a palladium-containing compound to form a supported-palladium composition, contacting the supported-palladium composition with a dopant to form a selective hydrogenation catalyst precursor, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof, and reducing the selective hydrogenation catalyst precursor to form the selective hydrogenation catalyst. A selective hydrogenation catalyst produced via the method of making a selective hydrogenation catalyst, and a method of selectively hydrogenating highly unsaturated hydrocarbons to an unsaturated hydrocarbon enriched composition are also provided.

A process for producing a catalyst, comprising the steps of modifying a carrier by a first impregnation with at least one alkaline earth metal in a first metal precursor solution, the first metal precursor being decomposed to form at least one metal oxide or metal hydroxide, thereby obtaining a modified carrier. A second impregnation is carried out by incipient wetness by a second precursor solution comprising at least one metal Me in a second solution. Finally, the second precursor is decomposed, thereby obtaining a catalyst body having an enrichment of the at least one metal Me in the outer shell of the catalyst body, the metal being present in a concentration having either as an egg-shell profile or a hammock profile.

The present invention relates to a novel process for oxidative esterification, generally for reaction of aldehydes with alcohols in the presence of oxygenous gases directly to give the corresponding ester in the presence of a heterogeneous catalyst, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The new catalyst has titanium dioxide as the main component of the support material. The catalysts are especially notable for high mechanical and chemical stability and for good catalytic performance even over very long periods. The process is an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.