This exhaust gas purifying catalyst is provided with a substrate 10 and a catalyst layer 20 formed on a surface of the substrate 10. The catalyst layer 20 contains zeolite particles 22 that support a metal, and a rare earth element-containing compound 24 that contains a rare earth element. The rare earth element-containing compound 24 is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite 22 is 0.001 to 0.014 in terms of oxides.

A catalyst for preparing light olefin using direct conversion of syngas is a composite catalyst and formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide; and the component II is one or more than one of zeolite of CHA and AEI structures or metal modified CHA and/or AEI zeolite. A weight ratio of the active ingredients in the component I to the component II is 0.1-20. The reaction process has high product yield and selectivity, wherein the sum of the selectivity of the propylene and butylene reaches 40-75%; and the sum of the selectivity of light olefin comprising ethylene, propylene and butylene can reach 50-90%. Meanwhile, the selectivity of a methane side product is less than 15%.

A catalyst for preparing light olefin using direct conversion of syngas is a composite catalyst and formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide; and the component II is one or more than one of zeolite of CHA and AEI structures or metal modified CHA and/or AEI zeolite. A weight ratio of the active ingredients in the component I to the component II is 0.1-20. The reaction process has high product yield and selectivity, wherein the sum of the selectivity of the propylene and butylene reaches 40-75%; and the sum of the selectivity of light olefin comprising ethylene, propylene and butylene can reach 50-90%. Meanwhile, the selectivity of a methane side product is less than 15%.

A method for the removal of nitrous oxide from off gas by direct decomposition or by selective catalytic reduction in presence of a reducing agent, comprising the steps of contacting the gas directly or together with the reducing agent or a precursor thereof with a catalyst comprising an Fe-AEI zeolite material essentially free of alkali metal ions (Alk) and having the following molar compositions:
SiO.sub.2: oAl.sub.2O.sub.3: pFe: qAlk wherein o is in the range from 0.001 to 0.2; wherein p is in the range from 0.001 to 0.2; wherein Alk is one or more of alkali ions and wherein q is less than 0.02.

A method for the removal of nitrous oxide from off gas by direct decomposition or by selective catalytic reduction in presence of a reducing agent, comprising the steps of contacting the gas directly or together with the reducing agent or a precursor thereof with a catalyst comprising an Fe-AEI zeolite material essentially free of alkali metal ions (Alk) and having the following molar compositions:
SiO.sub.2: oAl.sub.2O.sub.3: pFe: qAlk wherein o is in the range from 0.001 to 0.2; wherein p is in the range from 0.001 to 0.2; wherein Alk is one or more of alkali ions and wherein q is less than 0.02.

A composite catalyst containing heteroatom-doped zeolite for preparing light olefin using direct conversion of syngas formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide, and the component II is a heteroatom-doped zeolite. The zeolite topology is CHA or AEI, and the skeleton atoms include Al—P—O or Si—Al—P—O; the heteroatoms is at least one of divalent metal Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Mo, Cd, Ba and Ce, trivalent metal Ti and Ga, and tetravalent metal Ge. A weight ratio of the active ingredient in the component I to the component II is 0.1-20. The reaction process has high light olefin selectivity; the sum selectivity of the light olefin including ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.

A cold start catalyst is disclosed. The cold start catalyst is effective to adsorb NO.sub.x and hydrocarbons (HC) at or below a low temperature and to covert and release the adsorbed NO.sub.x and HC at temperatures above the low temperature. The cold start catalyst comprises a molecular sieve catalyst and a supported platinum group metal catalyst. The molecular sieve catalyst consists essentially of a noble metal and a molecular sieve. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst, and a method for treating exhaust gas from an internal combustion engine utilizing the cold start catalyst.

This exhaust gas purifying catalyst is provided with a substrate and a catalyst layer formed on a surface of the substrate. The catalyst layer contains zeolite particles that support a metal, and a rare earth element-containing compound that contains a rare earth element. The rare earth element-containing compound is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite is 0.001 to 0.014 in terms of oxides.

An AFI-CHA hybrid crystal molecular sieve and an NH.sub.3—SCR catalyst using the AFI-CHA hybrid crystal molecular sieve as a carrier, and preparation methods thereof are disclosed. The AFI-CHA hybrid crystal molecular sieve includes an AFI-type SAPO-5 molecular sieve and a CHA-type SAPO-34 molecular sieve, with hybrid crystal grains of AFI and CHA. The hybrid crystal molecular sieve is synthesized by a hydrothermal synthesis method and can be obtained by changing the structure directing agent, the heating rate and the calcinating temperature in the preparation process. Further, copper is loaded on the basis of the hybrid crystal molecular sieve to prepare copper-based NH.sub.3—SCR catalyst and corresponding monolithic catalyst. The catalytic activity and hydrothermal stability of the catalyst are significantly improved by the hybrid crystal molecular sieve.

The present disclosure provides an aromatization catalyst, a preparation method, a regeneration method and an aromatization method thereof. The preparation method comprises steps of: mixing a zeolite molecular sieve with a binder to obtain a catalyst precursor; the catalyst precursor is successively subjected to an ion exchange modification and a first modification treatment, and then subjected to a hydrothermal treatment, and further subjected to active metal loading and a second modification treatment, to obtain the aromatization catalyst. The aromatization catalyst has good carbon deposition resistance and high aromatization activity, and enables an aromatization reaction to be completed under mild conditions, and has high aromatic selectivity, and the liquid yield is above 98.5%.