The present disclosure relates to an isomerization method of a cyclohexane dicarboxylic acid (CHDA) and, more specifically, to a method for preparing a trans-cyclohexane dicarboxylic acid (t-CHDA) from a cis-cyclohexane dicarboxylic acid (c-CHDA) by means of catalytic isomerization.

Particularly, an embodiment of the present disclosure provides a method for preparing, in high efficiency and high yield and at a low cost, a CHDA having a high t-CHDA content from a CHDA mainly containing c-CHDA, by using an isomerization catalyst containing zirconia and having a BET specific surface area of 50 m.sup.2/g or more.

A Ni—Al.sub.2O.sub.3@Al.sub.2O.sub.3—SiO.sub.2 catalyst with coated structure is provided. The catalyst has a specific surface area of 98 m.sup.2/g to 245 m.sup.2/g, and a pore volume of 0.25 cm.sup.3/g to 1.1 cm.sup.3/g. A mass ratio of an Al.sub.2O.sub.3 carrier to active component Ni in the catalyst is Al.sub.2O.sub.3:Ni=100:4˜26, a mass ratio of the Al.sub.2O.sub.3 carrier to an Al.sub.2O.sub.3—SiO.sub.2 coating layer is Al.sub.2O.sub.3:Al.sub.2O.sub.3—SiO.sub.2=100:0.1˜3, and a molar ratio of Al to Si in the Al.sub.2O.sub.3—SiO.sub.2 coating layer is 0.01 to 1. Ni particles are distributed on a surface of the Al.sub.2O.sub.3 carrier in an amorphous or highly dispersed state and have a grain size less than or equal to 8 nm, and the coating layer is filled among the Ni particles.

A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.

An object of the present invention is to provide means for releasing oxygen at a temperature lower than conventional means in an exhaust gas purification catalyst. A Ce—Zr composite oxide is provided, which has a crystallite diameter of 6.5 nm or less and a BET specific surface area of 90 m.sup.2/g or more.

The present invention addresses to catalysts applicable to the conversion of CO to CO.sub.2 and H.sub.2 by the water-gas shift reaction. Such catalysts are made up of iron oxides, zirconium oxides, cerium oxides or a mixture of the same, promoted by platinum (Pt) contents between 0.1 and 0.4% m/m and with a sodium (Na) content below 0.01% m/m, based on the oxidized material. The present invention makes it possible to obtain catalysts with a high dispersion of Pt, with metallic particles of the order of 1 nm and methods of preparation by coprecipitation of soluble salts in aqueous medium using ammonium hydroxide as a precipitating agent.

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

Disclosed herein are a catalyst composition, catalyst devices, and methods for removing formaldehyde, volatile organic compounds, and other pollutants from an air flow stream. The catalyst composition including manganese oxide, optionally one or more of alkali metals, alkaline earth metals, zinc, iron, binder, an inorganic oxide, or carbon.

Disclosed are a catalyst for preparing hydrocarbons from carbon dioxide by one-step hydrogenation and a method for preparing same. The catalyst includes nano-metal oxides and hierarchical zeolites, where the mass fraction of the nano-metal oxides in the catalyst is 10%-90%, and the mass fraction of the hierarchical zeolites in the catalyst is 10%-90%. The catalyst has excellent catalytic performance, good reaction stability and high selectivity for desired products, and in the hydrocarbons, C.sub.2.sup.=-C.sub.4.sup.= reach up to 80%, C.sub.5+ reach up to 80%, and aromatics reach up to 65%.

A method of manufacturing a methane oxidation catalyst and methane oxidation catalysts formed by the method are provided. The method includes providing a palladium (Pd)-based catalyst including Pd dispersed onto a support. A magnesium (Mg) precursor is introduced to the Pd-based catalyst by one of ion exchange or incipient wetness impregnation. After introducing the magnesium precursor to the Pd-based catalyst, the catalyst is dried and subjected to a final heat treatment that includes hydrothermal calcination. A method of methane oxidation in a lean exhaust environment via the methane oxidation catalyst is also provided.

A nickel-iron alloy hydrogenation catalyst and a fabricating method thereof are provided. The nickel-iron alloy hydrogenation catalyst has 65 to 95 atomic percent nickel; and 5 to 35 atomic percent of iron, wherein the nickel-iron alloy hydrogenation catalyst is spherical and has an average particle diameter of 180 to 300 nm. The nickel-iron alloy hydrogenation catalyst is present in a non-carrier form. The nickel-iron alloy hydrogenation catalyst can generate a hydrogenation reaction at a low temperature (about 130˜140° C.) and has a high conversion rate (compared to pure nickel catalyst).