Metal oxides are provided that have selective hydrogen combustion activity while also acting as solid oxygen carriers (SOCs). The metal oxides correspond to a metal oxide core of at least one metal having multiple oxidation states that is modified with an alkali metal oxide and/or alkali metal halogen (such as an alkali metal chloride). The resulting modified metal oxide, corresponding to a solid oxygen carrier, can allow for selective combustion of hydrogen while reducing or minimizing combustion of hydrocarbons, such as within a propane dehydrogenation environment. Additionally, it has been unexpectedly found that modifying the core metal oxide with the alkali metal oxide and/or alkali metal chloride can also mitigate coke formation on the solid oxygen carrier. Methods of using such metal oxides for selective hydrogen combustion are also provided.

Metal oxides are provided that have selective hydrogen combustion activity while also acting as solid oxygen carriers (SOCs). The metal oxides correspond to a metal oxide core of at least one metal having multiple oxidation states that is modified with an alkali metal oxide and/or alkali metal halogen (such as an alkali metal chloride). The resulting modified metal oxide, corresponding to a solid oxygen carrier, can allow for selective combustion of hydrogen while reducing or minimizing combustion of hydrocarbons, such as within a propane dehydrogenation environment. Additionally, it has been unexpectedly found that modifying the core metal oxide with the alkali metal oxide and/or alkali metal chloride can also mitigate coke formation on the solid oxygen carrier. Methods of using such metal oxides for selective hydrogen combustion are also provided.

The disclosure relates to a single-atom-based catalyst system with total-length control of single-atom catalytic sites. The single-atom-based catalyst system comprises at least one catalyst structure comprising a first assembly of a plurality of single-atom-catalyst superparticles. The single-atom-catalyst superparticles comprise a second assembly of a plurality of single-atom-catalyst nanoparticles. The single-atom-based catalyst system has controlled porosity and spatial distribution of active single-atom catalysts from the atomic scale to the macroscopic scale. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

The disclosure relates to a single-atom-based catalyst system with total-length control of single-atom catalytic sites. The single-atom-based catalyst system comprises at least one catalyst structure comprising a first assembly of a plurality of single-atom-catalyst superparticles. The single-atom-catalyst superparticles comprise a second assembly of a plurality of single-atom-catalyst nanoparticles. The single-atom-based catalyst system has controlled porosity and spatial distribution of active single-atom catalysts from the atomic scale to the macroscopic scale. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

A process for producing ethylene and syngas comprising reacting, via OCM, first reactant mixture (CH.sub.4&O.sub.2) in first reaction zone comprising OCM catalyst to produce first product mixture comprising ethylene, ethane, hydrogen, CO.sub.2, CO, and unreacted methane; introducing second reactant mixture comprising first product mixture to second reaction zone excluding catalyst to produce second product mixture comprising ethylene, ethane, hydrogen, CO, CO.sub.2, and unreacted methane, wherein a common reactor comprises both the first and second reaction zones, wherein ethane of second reactant mixture undergoes cracking to ethylene, wherein CO.sub.2 of second reactant mixture undergoes hydrogenation to CO, and wherein an amount of ethylene in the second product mixture is greater than in the first product mixture; recovering methane stream, ethane stream, CO.sub.2 stream, ethylene stream, and syngas stream (CO&H.sub.2) from the second product mixture; and recycling the ethane stream and the carbon dioxide stream to second reaction zone.

A process for producing ethylene and syngas comprising reacting, via OCM, first reactant mixture (CH.sub.4&O.sub.2) in first reaction zone comprising OCM catalyst to produce first product mixture comprising ethylene, ethane, hydrogen, CO.sub.2, CO, and unreacted methane; introducing second reactant mixture comprising first product mixture to second reaction zone excluding catalyst to produce second product mixture comprising ethylene, ethane, hydrogen, CO, CO.sub.2, and unreacted methane, wherein a common reactor comprises both the first and second reaction zones, wherein ethane of second reactant mixture undergoes cracking to ethylene, wherein CO.sub.2 of second reactant mixture undergoes hydrogenation to CO, and wherein an amount of ethylene in the second product mixture is greater than in the first product mixture; recovering methane stream, ethane stream, CO.sub.2 stream, ethylene stream, and syngas stream (CO&H.sub.2) from the second product mixture; and recycling the ethane stream and the carbon dioxide stream to second reaction zone.

Mixed metal oxide catalysts having an amorphous content of not less than 40 wt. % are prepared by calcining the catalyst precursor fully or partially enclosed by a porous material having a melting temperature greater than 600° C. in an inert container including heating the catalyst precursor at a rate from 0.5 to 10° C. per minute from room temperature to a temperature from 370° C. to 540° C. under a stream of pre heated gas chosen from steam and inert gas and mixtures thereof at a pressure of greater than or equal to 1 psig having a temperature from 300° C. to 540° C. and holding the catalyst precursor at that temperature for at least 2 hours and cooling the catalyst precursor to room temperature.

Mixed metal oxide catalysts having an amorphous content of not less than 40 wt. % are prepared by calcining the catalyst precursor fully or partially enclosed by a porous material having a melting temperature greater than 600° C. in an inert container including heating the catalyst precursor at a rate from 0.5 to 10° C. per minute from room temperature to a temperature from 370° C. to 540° C. under a stream of pre heated gas chosen from steam and inert gas and mixtures thereof at a pressure of greater than or equal to 1 psig having a temperature from 300° C. to 540° C. and holding the catalyst precursor at that temperature for at least 2 hours and cooling the catalyst precursor to room temperature.

Provided is a process for converting an alkane to an alkene. The process comprises (a) contacting the alkane and either (i) an oxidizing electrophile comprising a main group element in oxidized form, or (ii) an oxidant and a reduced form of the oxidizing electrophile, in a liquid medium comprising an oxygen acid and optionally one or more additives selected from a non-oxidizable liquid, a salt additive, a Lewis acid, and water, to provide an oxidized intermediate and a reduced form of the oxidizing electrophile; (b) optionally separating the oxidized intermediate and the reduced form of the oxidizing electrophile; and (c) performing an elimination reaction on the oxidized intermediate to provide the alkene and the oxygen acid.

Provided is a process for converting an alkane to an alkene. The process comprises (a) contacting the alkane and either (i) an oxidizing electrophile comprising a main group element in oxidized form, or (ii) an oxidant and a reduced form of the oxidizing electrophile, in a liquid medium comprising an oxygen acid and optionally one or more additives selected from a non-oxidizable liquid, a salt additive, a Lewis acid, and water, to provide an oxidized intermediate and a reduced form of the oxidizing electrophile; (b) optionally separating the oxidized intermediate and the reduced form of the oxidizing electrophile; and (c) performing an elimination reaction on the oxidized intermediate to provide the alkene and the oxygen acid.