A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing an oxygen carrier having oxygen ionic conductivity, and a basic oxide supported on the oxygen carrier. In addition, the basic oxide preferably contains at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), cobalt (Co), strontium (Sr), and rubidium (Rb). The reducing agent has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

A supported catalyst for decomposing an organic substance that includes a support and a catalyst particle supported on the support. The catalyst particle contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni and Fe, y+z=1, x≥0.995, z≤0.4, and w is a positive value satisfying electrical neutrality. A film thickness of a catalyst-supporting film supported on the support and containing the catalyst particle is 5 μm or more, or a supported amount as determined by normalizing a mass of the catalyst particle supported on the support by a volume of the support is 45 g/L or more.

Methods and systems for converting methane to syngas are provided. Certain exemplary methods and systems involve reacting methane and carbon dioxide with a nickel oxide catalyst in a reaction chamber, thereby providing syngas and a reduced nickel species. The reduced nickel species can be regenerated by oxidation with air in a regeneration chamber, thereby generating a regenerated nickel oxide and heat. The regenerated nickel oxide and heat can be returned to the reaction chamber to drive the syngas reaction.

This disclosure features a urea conversion catalyst located within a urea decomposition reactor (e.g., a urea decomposition pipe) of a diesel exhaust aftertreatment system. The urea conversion catalyst includes a refractory metal oxide and a cationic dopant. The urea conversion catalyst can decrease the temperature at which urea converts to ammonia, can increase the urea conversion yield, and can decrease the likelihood of incomplete urea conversion.

This disclosure features a urea conversion catalyst located within a urea decomposition reactor (e.g., a urea decomposition pipe) of a diesel exhaust aftertreatment system. The urea conversion catalyst includes a refractory metal oxide and a cationic dopant. The urea conversion catalyst can decrease the temperature at which urea converts to ammonia, can increase the urea conversion yield, and can decrease the likelihood of incomplete urea conversion.

A new process for the decomposition of hydrocarbon feed stream(s) that achieves the conversion of a hydrocarbon feed stream to hydrogen and filamentous carbon, with minimal resulting production of carbon oxides is described herein. In this invention it is proposed to achieve the hydrocarbon conversion by the use of dual fluidized bed reaction zones, fluidly connected, for (i). hydrocarbon reaction (the reactor) and (ii). catalyst regeneration and heating (the regenerator) and to use a transition metal supported catalyst to achieve high hydrocarbon conversion and to produce high quality filamentous carbon.

A new process for the decomposition of hydrocarbon feed stream(s) that achieves the conversion of a hydrocarbon feed stream to hydrogen and filamentous carbon, with minimal resulting production of carbon oxides is described herein. In this invention it is proposed to achieve the hydrocarbon conversion by the use of dual fluidized bed reaction zones, fluidly connected, for (i). hydrocarbon reaction (the reactor) and (ii). catalyst regeneration and heating (the regenerator) and to use a transition metal supported catalyst to achieve high hydrocarbon conversion and to produce high quality filamentous carbon.

Process for the removal of NOx (NO, NO2) and nitrous oxide (N2O) contained in a process off-gas comprising the steps of (a) adding an amount of a NOx reducing agent into the process off-gas;(b) in a first stage passing the process off-gas admixed with the reducing agent through a catalyst active in selective catalytic reduction of NOx with the reducing agent and providing an effluent gas comprising the nitrous oxide and residual amounts of reducing agent; and(c) in a second stage passing the effluent gas through a catalyst comprising a cobalt compound and being active in decomposition of nitrous oxide and oxidation of the residual amounts of the reducing agent.

Process for the removal of NOx (NO, NO2) and nitrous oxide (N2O) contained in a process off-gas comprising the steps of (a) adding an amount of a NOx reducing agent into the process off-gas;(b) in a first stage passing the process off-gas admixed with the reducing agent through a catalyst active in selective catalytic reduction of NOx with the reducing agent and providing an effluent gas comprising the nitrous oxide and residual amounts of reducing agent; and(c) in a second stage passing the effluent gas through a catalyst comprising a cobalt compound and being active in decomposition of nitrous oxide and oxidation of the residual amounts of the reducing agent.