The present disclosure is directed to a method for treating a gaseous exhaust stream containing nitrogen oxides (NO.sub.x) from a diesel or lean-burn gasoline engine following a cold-start of the engine The method involves contact of the gaseous exhaust stream with at least a low temperature NO.sub.x adsorber (LT-NA) component. The LT-NA component includes a rare earth metal component, a platinum group metal (PGM) component, and a dopant. The present disclosure is also directed to a method of modulating a NO.sub.x adsorption/desorption profile of an LT-NA composition, a NO.sub.x desorption temperature range of an LT-NA composition, or both.

A method of producing a hydrofluoroolefin includes reacting a chlorofluoroolefin that is represented by Formula (I) or Formula (II) and that has 8 or less carbon atoms with a hydrogen molecule, in the presence of an intermetallic compound containing at least one first metal that is selected from the group consisting of palladium, platinum, rhodium, copper and iridium, and containing a second metal that is different from the first metal, to obtain a hydrofluoroolefin in which a hydrogen atom is substituted for at least a chlorine atom represented by Cl among chlorine atoms contained in Formula (I) or Formula (II). ##STR00001##

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: antimony (Sb) or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide; wherein the platinum group metal (PGM) and the antimony (Sb) or an oxide thereof is each supported on the support material.

A catalytic composite for a cyclic process of adiabatic, non-oxidative dehydrogenation of an alkane into an olefin, comprising a dehydrogenation catalyst, a semimetal and a carrier supporting the catalyst and the semimetal. During the reduction and/or regeneration stages of the adiabatic process, the semimetal releases heat which can be used to initiate the dehydrogenation reactions, which are endothermic in nature, thereby reducing the need for hot air flow and combustion of coke as heat input. The semi-metal is inert towards the dehydrogenation reaction itself, alkane feed and olefin product as well as other side reactions of the cyclic process such as cracking and decoking.

This invention relates to heterogeneous catalysts useful for selective hydrogenation of unsaturated hydrocarbons, comprising palladium and optionally a promoter, supported on a substrate, having an uncoated BET surface area of 9 m.sup.2/g, the surface being coated with an ionic liquid. Also described are methods of making the catalysts and methods of selective hydrogenation of acetylene and/or dienes in front-end mixed olefin feed streams.

This invention relates to heterogeneous catalysts useful for selective hydrogenation of unsaturated hydrocarbons, comprising palladium and optionally a promoter, supported on a substrate, having an uncoated BET surface area of 9 m.sup.2/g, the surface being coated with an ionic liquid. Also described are methods of making the catalysts and methods of selective hydrogenation of acetylene and/or dienes in front-end mixed olefin feed streams.

Electrocatalyst, electrode coating and an electrode for preparing chlorine and process for producing the electrode, the electrocatalyst comprising a noble metal oxide and/or a noble metal of transition groups VIIIa of the Periodic Table of the Elements and at least one finely divided pulverulent oxide of another metal, in which one or more components are doped and the base metal oxide powder is chemically stable in the presence of aqueous electrolytes.

A process for producing methyl methacrylate, the process comprising contacting reactants comprising methacrolein, methanol and an oxygen-containing gas, under reaction conditions in the presence of a solid catalyst comprising palladium, bismuth and at least one third element X, where X is selected from the group consisting of P, S, Sc, V, Ga, Se, Y, Nb, Mo, La, Ce, and Nd, wherein the solid catalyst further comprises a support selected from at least one member of the group consisting of silica, alumina, calcium carbonate, active carbon, zinc oxide, titanium oxide and magnesium oxide.

To provide a method for producing a hydrofluoroolefin, wherein formation of an over-reduced product having hydrogen added to a material chlorofluoroolefin and an over-reduced product having not only chlorine atoms but also fluorine atoms in the chlorofluoroolefin replaced with hydrogen atoms, as by-products, is suppressed.

A method for producing a hydrofluoroolefin, which comprises reacting a specific chlorofluoroolefin with hydrogen in the presence of a catalyst supported on a carrier, to obtain a specific hydrofluoroolefin, wherein the catalyst is a catalyst composed of an alloy containing at least one platinum group element selected from the group consisting of palladium and platinum, and at least one second element selected from the group consisting of manganese, copper, aluminum, gold, lithium, sodium, potassium, magnesium, silver, zinc, cadmium, indium, silicon, germanium, tin, lead, arsenic, antimony and bismuth.

A metal oxide supported palladium catalyst comprised of a -Bi.sub.2O.sub.3/Bi.sub.2Sn.sub.2O.sub.7 hetero-junction catalyst support and palladium was developed. The catalyst was synthesized using a sol-gel technique as a nanocrystalline structure. In the presence of fluorene, an oxidant and ultraviolet irradiation, the catalyst converts the hydrocarbon to a mixture of fluorenol/fluorenone oxidation products. The close proximity between -Bi.sub.2O.sub.3 and Bi.sub.2Sn.sub.2O.sub.7 heterojunction phases in the catalyst is thought to be responsible for the efficient charge separation and catalytic activity. An indirect chemical probe method using active species scavengers elucidated that the photo-oxidation mechanism proceeds via holes and superoxide radical (O.sub.2..sup.) moieties.