Disclosed in the present invention is an integrated catalyst system for stoichiometric-burn natural gas vehicles, the catalyst system consisting of a three-way catalyst, a molecular sieve catalyst, and a base body, the three-way catalyst and the molecular sieve catalyst being coated on a surface of the base body. In the integrated three-way catalyst and molecular sieve catalyst system of the present invention, at the same time that pollutants such as CO, HC, and NO.sub.x in the exhaust of stoichiometric-burn natural gas vehicles are processed, the produced byproduct NH.sub.3 can also be processed, and the conversion rates of CO, HC, NO.sub.x, and NH.sub.3 are high.

A fluid catalytic cracking catalyst for hydrocarbon oil that is a blend of two types of fluid catalytic cracking catalysts each of which has a different hydrogen transfer reaction activity or has a pore distribution within a specific range after being pseudo-equilibrated. One catalyst is a catalyst containing a zeolite and matrix components, and the other catalyst is a catalyst containing a zeolite and matrix components. This catalyst is composed of the one catalyst and the other catalyst blended at a mass ratio within a range of 10:90 to 90:10.

A fluid catalytic cracking catalyst for hydrocarbon oil that is a blend of two types of fluid catalytic cracking catalysts each of which has a different hydrogen transfer reaction activity or has a pore distribution within a specific range after being pseudo-equilibrated. One catalyst is a catalyst containing a zeolite and matrix components, and the other catalyst is a catalyst containing a zeolite and matrix components. This catalyst is composed of the one catalyst and the other catalyst blended at a mass ratio within a range of 10:90 to 90:10.

Novel MEL framework type zeolites can be made to have small crystallite sizes and desirable silica/SiCb molar ratios. Catalyst compositions comprising such MEL framework type zeolites can be particularly advantageous in isomerization C8 aromatic mixtures. An isomerization process for converting C8 aromatic hydrocarbons can advantageously utilize a catalyst composition comprising a MEL framework type zeolite.

Novel MEL framework type zeolites can be made to have small crystallite sizes and desirable silica/SiCb molar ratios. Catalyst compositions comprising such MEL framework type zeolites can be particularly advantageous in isomerization C8 aromatic mixtures. An isomerization process for converting C8 aromatic hydrocarbons can advantageously utilize a catalyst composition comprising a MEL framework type zeolite.

The present disclosure provides a method of preparing a SCR (Selective Catalytic Reduction) catalyst including preparing a synthetic mother liquid that includes a source of silica and alumina including zeolite A and silica, a structure-inducing material, a complexing material, and a solvent, reacting the synthetic mother liquid to prepare CHA zeolite, and ion-exchanging the prepared CHA zeolite with a transition metal.

The present disclosure provides a method of preparing a SCR (Selective Catalytic Reduction) catalyst including preparing a synthetic mother liquid that includes a source of silica and alumina including zeolite A and silica, a structure-inducing material, a complexing material, and a solvent, reacting the synthetic mother liquid to prepare CHA zeolite, and ion-exchanging the prepared CHA zeolite with a transition metal.

Disclosed are a catalyst and a preparation method therefor, the catalyst being able to maintain a high production yield of C8 aromatic hydrocarbons in the process of converting a feedstock containing alkyl aromatics to C8 aromatic hydrocarbons such as mixed xylene through disproportionation/transalkylation/dealkylation while reducing a content of ethylbenzene in the products.

Disclosed are a catalyst and a preparation method therefor, the catalyst being able to maintain a high production yield of C8 aromatic hydrocarbons in the process of converting a feedstock containing alkyl aromatics to C8 aromatic hydrocarbons such as mixed xylene through disproportionation/transalkylation/dealkylation while reducing a content of ethylbenzene in the products.

A catalytic cracking catalyst contains 10-70 wt % of a cracking active component, 10-60 wt % of a binder and 10-70 wt % of a clay. The cracking active component has 5-100 wt % of a first Y-type molecular sieve and 0-95 wt % of a second molecular sieve. The first Y-type molecular sieve is a modified molecular sieve based on the crystal modification of kaolin and has the sodium oxide content of less than 2 wt %. The process for preparing the catalyst includes the steps of vigorously mixing and stirring a cracking active component comprising a modified molecular sieve based on the crystal modification of kaolin, a binder and a clay with water; spray drying; washing; filtering; and drying. The catalyst is used in the catalytic cracking reaction of heavy oils, and has a good coke selectivity, as well as a higher heavy oil conversion rate.