The presently claimed invention relates an automotive catalyst system which can be used to selectively reduce carbon monoxide. The system comprises a first close coupled three-way conversion catalytic article in fluid communication with an engine exhaust outlet, a catalytic article located downstream of and in fluid communication with the first close coupled three-way conversion catalytic article, a tail-pipe catalytic article arranged downstream in fluid communication and 1.0 to 10 feet away from the catalytic article at a position selected from before or behind a resonator, before or after a muffler, between the resonator and the muffler, inside the muffler, inside the resonator, and at a tail pipe end.

The oxidative coupling of methane (OCM) and the oxidative dehydrogenation (ODH) of ethane and higher hydrocarbons is described using SO.sub.3 and sulfate, sulfite, bisulfite and metabifulfite salts as oxygen transfer agents in the presence of one or more elements selected from Groups 3 to 14 of the periodic table, optionally further in the presence of alkali or alkaline salts and/or sulfur-containing compounds.

The present disclosure provides perovskite catalytic materials and catalysts comprising platinum-group metals and perovskites. These catalysts may be used as oxygen storage materials with automotive applications, such as three-way catalysts. They are also useful for water or CO.sub.2 reduction, or thermochemical energy storage.

The present disclosure provides perovskite catalytic materials and catalysts comprising platinum-group metals and perovskites. These catalysts may be used as oxygen storage materials with automotive applications, such as three-way catalysts. They are also useful for water or CO.sub.2 reduction, or thermochemical energy storage.

An exhaust gas purifying catalyst for 2-stroke general-purpose engines, which is characterized in that: the exhaust gas purifying catalyst includes a base and a coat layer on the base; the coat layer contains noble metals and metal oxides; the noble metals include palladium and one or more elements selected from among platinum and rhodium; the zirconia content in the coat layer is 0.07 mole or less per 100 g of the metal oxides contained in the coat layer; and the total content of one or more metal oxides selected from among lanthana and alkaline earth metal oxides in the coat layer is 0.05 mole or more per 100 g of the metal oxides contained in the coat layer.

An exhaust gas purifying catalyst for 2-stroke general-purpose engines, which is characterized in that: the exhaust gas purifying catalyst includes a base and a coat layer on the base; the coat layer contains noble metals and metal oxides; the noble metals include palladium and one or more elements selected from among platinum and rhodium; the zirconia content in the coat layer is 0.07 mole or less per 100 g of the metal oxides contained in the coat layer; and the total content of one or more metal oxides selected from among lanthana and alkaline earth metal oxides in the coat layer is 0.05 mole or more per 100 g of the metal oxides contained in the coat layer.

Embodiments of the present disclosure are directed to hydrogen-selective oxygen carrier materials and methods of using hydrogen-selective oxygen carrier materials. The hydrogen-selective oxygen carrier material may comprise a core material, which includes a redox-active transition metal oxide; a shell material, which includes one or more alkali transition metal oxides; and a support material. The shell material may be in direct contact with at least a majority of an outer surface of the core material. At least a portion of the core material may be in direct contact with the support material. The hydrogen-selective oxygen carrier material may be selective to combust hydrogen in an environment that includes hydrogen and hydrocarbons.

Embodiments of the present disclosure are directed to hydrogen-selective oxygen carrier materials and methods of using hydrogen-selective oxygen carrier materials. The hydrogen-selective oxygen carrier material may comprise a core material, which includes a redox-active transition metal oxide; a shell material, which includes one or more alkali transition metal oxides; and a support material. The shell material may be in direct contact with at least a majority of an outer surface of the core material. At least a portion of the core material may be in direct contact with the support material. The hydrogen-selective oxygen carrier material may be selective to combust hydrogen in an environment that includes hydrogen and hydrocarbons.

The invention relates to an oxygen carrier solid, its preparation and its use in a method of combustion of a hydrocarbon feedstock by active mass chemical-looping oxidation-reduction, i.e. chemical-looping combustion (CLC). The solid, which is in the form of particles, comprises an oxidation-reduction active mass composed of metal oxide(s) dispersed in a ceramic matrix comprising at least at least one feldspar or feldspathoid with a melting point higher than 1500° C., such as celsian, and has, initially, a specific macroporous texture. The oxygen carrier solid is prepared from a precursor of the ceramic matrix, obtained from a macroporous zeolitic material with zeolite crystals of a specific size, and a precursor of the oxidation-reduction active mass.

The invention relates to an oxygen carrier solid, its preparation and its use in a method of combustion of a hydrocarbon feedstock by active mass chemical-looping oxidation-reduction, i.e. chemical-looping combustion (CLC). The solid, which is in the form of particles, comprises an oxidation-reduction active mass composed of metal oxide(s) dispersed in a ceramic matrix comprising at least at least one feldspar or feldspathoid with a melting point higher than 1500° C., such as celsian, and has, initially, a specific macroporous texture. The oxygen carrier solid is prepared from a precursor of the ceramic matrix, obtained from a macroporous zeolitic material with zeolite crystals of a specific size, and a precursor of the oxidation-reduction active mass.