Methods for oxidative coupling of methane using metal oxide catalysts and a sulfur oxidant.

The present invention relates to a stabilized rhenium-based heterogeneous catalyst, obtainable by a process comprising contacting a rhenium-based heterogeneous catalyst with a stabilizing agent at a temperature in a range from 0-100° C., the stabilizing agent comprising an aliphatic hydrocarbon compound and use thereof.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx−1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx−1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

Systems and methods include providing a gaseous alkane input stream and metal sulfide (MSx) particles that can react with an alkane in the gaseous alkane input stream to generate an alkene, a reduced metal sulfide (MSx-1) particle, and at least one of: hydrogen sulfide (H2S) and at least one sulfur containing compound selected from: S2, CS, and CS2. A product stream can be collected that includes the alkene and at least one of: hydrogen sulfide (H2S) and the at least one sulfur containing compound. A reduced metal sulfide (MSx-1) particle reacts with sulfur in a sulfur stream and can generate the metal sulfide (MSx) particle and hydrogen (H2).

The present disclosure provides a method for the oxidative dehydrogenation of an alkane, e.g., ethane, propane, etc. In embodiments, a method for oxidative dehydrogenation of an alkane comprises exposing a gas comprising an alkane having 2 or more carbons to elemental sulfur vapor at an elevated reaction temperature and for a period of time to convert the alkane to one or more products via oxidative dehydrogenation, the one or more products comprising a primary alkene.

Disclosed herein are carbon doped tin disulphide (C—SnS.sub.2) and other SnS.sub.2 composites as visible light photocatalyst for CO.sub.2 reduction to solar fuels. The in situ carbon doped SnS.sub.2 photocatalyst provide higher efficiency than the undoped pure SnS.sub.2. Also disclosed herein are methods for preparing the catalysts.