A method is provided for refining an argon gas, in which oxygen is added to the argon gas containing hydrogen, carbon monoxide (CO), and oxygen as impurities so that the hydrogen and the CO are converted into water and carbon dioxide in a catalyst tower, or hydrogen is added to the argon gas so that the oxygen is converted into the water; the method including: monitoring the hydrogen, the CO, and the oxygen on an outlet side of the catalyst tower; and at least one of adding the oxygen to the argon gas when any one of the hydrogen and the CO is detected on the outlet side of the catalyst tower, and adding the hydrogen when the oxygen is detected, wherein the oxygen or the hydrogen to be added is intermittently added to the catalyst tower relative to continuous supply of the argon gas to the catalyst tower.

Provided is a catalyst having a core-shell structure (which employs a core comprised of a highly electrochemically stable, relatively inexpensive material and thereby reduces the amount of platinum used, while providing a better cost/performance ratio in catalytic activity as compared to when platinum particles are used as a catalyst) for use in an oxygen reduction reaction (cathode reaction in a fuel cell), and to provide an oxygen reduction method using the catalyst. Provided is a core-shell catalyst for use for an oxygen reduction reaction, including: a core that is comprised of silver; and a shell layer that comprised of platinum, the shell layer being comprised of platinum atoms constituting a (111) plane of or a (001) plane of a face centered cubic lattice, in the shell layer, a nearest neighbor platinum-platinum interatomic distance falling within the range of from 2.81 {acute over ()} to 2.95 {acute over ()}.

Materials, methods to prepare, and methods of use for partial oxidation of methane. Embodiments include delivering a metal ferrite oxygen carrier to a fuel reactor, wherein the metal ferrite oxygen carrier comprises MFexOy where 1x3 and 3y5, and where M comprise a Group II alkali earth metals; and delivering a gaseous stream that contains methane to the metal ferrite oxygen carrier in the fuel reactor and maintaining the fuel reactor at a reducing temperature sufficient to reduce some portion of the metal ferrite oxygen carrier and oxidize some portion of the methane containing gas stream. Embodiments further include generating gaseous products containing H.sub.2 and CO gas in the fuel reactor; withdrawing a product stream from the fuel reactor, where the gaseous products comprise the product stream, and where at least >50 vol. % of the product stream includes CO and H.sub.2; oxidizing the reduced carrier in an oxidizing reactor by contacting the reduced carrier and an oxidizing gas at an oxidizing temperature, where the oxidizing gas is comprised of oxygen, and where the oxidizing temperature is sufficient to generate an oxidizing reaction, where the reactants of the oxidizing reaction comprise some portion of the oxygen, some portion of the M component, and some portion of the FecOd component, and further wherein the product of the oxidizing reaction is a re-oxidized carrier that comprises some portion of the MFexOy; and delivering heat generated in the oxidizing reactor to the fuel reactor for the reaction of metal ferrite with methane.

A method is provided for refining an argon gas, in which oxygen is added to the argon gas containing hydrogen, carbon monoxide(CO), and oxygen as impurities so that the hydrogen and the CO are converted into water and carbon dioxide in a catalyst tower, or hydrogen is added to the argon gas so that the oxygen is converted into the water; the method including: monitoring the hydrogen, the CO, and the oxygen on an outlet side of the catalyst tower; and at least one of adding the oxygen to the argon gas when any one of the hydrogen and the CO is detected on the outlet side of the catalyst tower, and adding the hydrogen when the oxygen is detected, wherein the oxygen or the hydrogen to be added is intermittently added to the catalyst tower relative to continuous supply of the argon gas to the catalyst tower.

To provide a catalyst, which is formed from a perovskite oxide, for thermochemical fuel production, and a method of producing fuel using thermochemical fuel production that is capable of allowing a fuel to be produced in a thermochemical manner. Provided is a catalyst for thermochemical fuel production, which is used for producing the fuel from thermal energy by using a two-step thermochemical cycle of a first temperature and a second temperature that is equal to or lower than the first temperature, wherein the catalyst is formed from a perovskite oxide having a compositional formula of AXO.sub.3?? (provided that, 0???1). Here, A represents one or more of a rare-earth element (excluding Ce), an alkaline earth metal element, and an alkali metal element, X represents one or more of a transition metal element and a metalloid element, and O represents oxygen.

The invention relates to a process for the concentration of oxygen in extraterrestrial atmospheres having low oxygen concentrations, using a thermochemical cyclic process.