Abstract: 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 NOx in the exhaust of stoichiometric-burn natural gas vehicles are processed, the produced byproduct NH3 can also be processed, and the conversion rates of CO, HC, NOx, and NH3 are high.

Abstract: A method for preparing a molecular sieve SCR (selective catalytic reduction) catalyst and a prepared catalyst therethrough. In the method, several molecular sieves are mixed and modified by transition metal or rare-earth metal via ion exchange, then loaded Fe by equivalent-volume impregnation, and loaded Cu by one or more liquid ion exchange. This present invention, combined with several techniques, such as modification of stable molecular sieve by transition and rare-earth metal, Fe loading by equivalent-volume impregnation and Cu loading by one or more liquid ion exchange, and after through stable and effective modification and loading control, the obtained catalyst material is coated on a carrier substrate via size mixing and coating process to be prepared into an integral catalyst.

Abstract: Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe.

Abstract: The present invention discloses a method for preparing a catalyst, comprising the following steps: (1) taking a noble metal salt solution A, adding a modified alumina support material, stirring until uniform and standing; (2) drying the material obtained in step (1) in a vacuum, and calcining at 500° C.-600° C. for 1-4 hours to obtain a powder material containing the noble metal; (3) mixing the noble metal powder material, an adhesive and other components to be added, and ball-milling to obtain a uniform slurry; (4) preparing a noble metal solution B and adjusting pH to 0.5-1; and (5) mixing the slurry of the step (3) with the noble metal solution B, coating the mixture on a support, drying, and calcining at 500° C.-600° C. for 1-2 hours to obtain the target product. The method for preparing the catalyst of the present invention is simple, the conditions of the preparation process are easy to control and the preparation method has strong practicality.