A catalyst composition comprising a first platinum group metal (PGM) component and a first support material, wherein the first PGM component comprises platinum (Pt) and palladium (Pd) and is supported on the first support material; and wherein the first PGM component has a Pt:Pd molar ratio of from about 5:95 to about 95:5.

Described herein is the preparation of a 1,3,5-triazinyl benzimidazole and chemical intermediates used in the synthetic process.

A hydrogen sensitive film, a hydrogen sensor and a preparation thereof. The hydrogen sensitive film has a composite structure of an aerogel and a catalyst. The aerogel can adsorb hydrogen and undergo hydrogenation reaction with hydrogen. The catalyst is a nano-noble metal catalyst for catalyzing the hydrogenation reaction, and is distributed in pores of the aerogel. The hydrogen sensitive film is prepared by mixing a catalyst into an aerogel through physical compounding. The hydrogen sensor includes an insulating substrate layer, the hydrogen sensitive film and an electrode layer.

A hydrogen sensitive film, a hydrogen sensor and a preparation thereof. The hydrogen sensitive film has a composite structure of an aerogel and a catalyst. The aerogel can adsorb hydrogen and undergo hydrogenation reaction with hydrogen. The catalyst is a nano-noble metal catalyst for catalyzing the hydrogenation reaction, and is distributed in pores of the aerogel. The hydrogen sensitive film is prepared by mixing a catalyst into an aerogel through physical compounding. The hydrogen sensor includes an insulating substrate layer, the hydrogen sensitive film and an electrode layer.

Described are exhaust gas treatment systems for treatment of a gasoline engine exhaust gas stream. The exhaust gas treatment systems comprise an ammonia generating catalyst and an ammonia selective catalytic reduction (SCR) catalyst downstream of the ammonia generating catalyst. The ammonia generating catalyst comprises a NO.sub.x storage component, a refractory metal oxide support, a platinum component, and a palladium component. The ammonia generating catalyst is substantially free of ceria. The platinum and palladium components are present in a platinum to palladium ratio of greater than about 1 to 1.

Described are exhaust gas treatment systems for treatment of a gasoline engine exhaust gas stream. The exhaust gas treatment systems comprise an ammonia generating catalyst and an ammonia selective catalytic reduction (SCR) catalyst downstream of the ammonia generating catalyst. The ammonia generating catalyst comprises a NO.sub.x storage component, a refractory metal oxide support, a platinum component, and a palladium component. The ammonia generating catalyst is substantially free of ceria. The platinum and palladium components are present in a platinum to palladium ratio of greater than about 1 to 1.

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. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

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. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

Neuroactive steroid anaesthetic agents, methods for their preparation and compositions comprising the same are disclosed. Also provided are scaled up and/or GMP methods for preparing neuroactive steroids, such as alfaxalone, alfadolone and alfadolone acetate.

Neuroactive steroid anaesthetic agents, methods for their preparation and compositions comprising the same are disclosed. Also provided are scaled up and/or GMP methods for preparing neuroactive steroids, such as alfaxalone, alfadolone and alfadolone acetate.