A method of hydrogenating carbon dioxide comprises forming a tunable catalyst comprising at least one metal comprising a size within a range of from a single atom to about 999 nanometers and formulated to produce one or more carbon-containing compound. An electrochemical cell comprising a positive electrode, a negative electrode comprising the tunable catalyst, and an electrolyte between the positive electrode and the negative electrode is formed. Carbon dioxide is introduced to the negative electrode of the electrochemical cell and a potential difference is applied between the positive electrode and the negative electrode to selectively hydrogenate the carbon dioxide. The hydrogen ions are diffused through the electrochemical cell. The carbon dioxide at the negative electrode is hydrogenated to selectively form carbon monoxide, methane, or a desired ratio of carbon monoxide and methane. An electrochemical cell and a carbon dioxide hydrogenation system are also disclosed.

Herein discussed is an electrochemical reactor comprising a first electrode, wherein the first electrode is liquid when the reactor is in operation; a second electrode having a metallic phase and a ceramic phase, wherein the metallic phase is electronically conductive and wherein the ceramic phase is ionically conductive; and a membrane, wherein the membrane is positioned between the first and second electrodes and is in contact with the first and second electrodes, wherein the membrane is mixed conducting. Also discussed herein is a method of producing hydrogen or carbon monoxide comprising: (a) providing an electrochemical reactor having an anode, a cathode, and a membrane between the anode and the cathode, wherein the anode is liquid when the reactor is in operation and wherein the membrane is mixed conducting; (b) introducing a feedstock to the anode; (c) introducing a stream to the cathode, wherein the stream comprises water or carbon dioxide.

Herein discussed is an electrochemical reactor comprising a first electrode, wherein the first electrode is liquid when the reactor is in operation; a second electrode having a metallic phase and a ceramic phase, wherein the metallic phase is electronically conductive and wherein the ceramic phase is ionically conductive; and a membrane, wherein the membrane is positioned between the first and second electrodes and is in contact with the first and second electrodes, wherein the membrane is mixed conducting. Also discussed herein is a method of producing hydrogen or carbon monoxide comprising: (a) providing an electrochemical reactor having an anode, a cathode, and a membrane between the anode and the cathode, wherein the anode is liquid when the reactor is in operation and wherein the membrane is mixed conducting; (b) introducing a feedstock to the anode; (c) introducing a stream to the cathode, wherein the stream comprises water or carbon dioxide.

A method for producing a transparent electrode for oxygen production having a Ta nitride layer on a transparent substrate, including: a step of forming a Ta nitride precursor layer on the transparent substrate; and a step of nitriding the Ta nitride precursor layer with a mixed gas containing ammonia and a carrier gas.

An electrode catalyst in which a metal or a metal oxide is supported on an electrode support composed of a conductive substance is provided. It is preferable that the electrode support contain one or more metals which are selected from the group consisting of a transition metal and a typical metal in Groups 12 to 14 or a carbon material and the metal or the metal oxide contain one or more metals which are selected from the group consisting of a transition metal and a typical metal in Groups 12 to 14 or a metal oxide.

A copper-palladium-loaded mesoporous silicon carbide-based catalyst, a preparation method, and an application thereof are provided. First, a mesoporous silicon carbide material is prepared by using mesoporous silica as a hard template; subsequently, the mesoporous silicon carbide material is mixed with a copper-palladium precursor mixed solution, and dried after the solvent is completely volatilized. The dried powder is successively subjected to calcination with N.sub.2 and reduction with H.sub.2 to finally obtain the copper-palladium-loaded mesoporous silicon carbide-based catalyst. The catalyst is made into an electrode, and the nitrate in water body is catalytically reduced by electrochemical method. The preparation method of the catalyst of the present invention is simple. The catalyst can realize high-efficiency catalytic denitrification at a low metal loading amount, with high selectivity of nitrogen. Moreover, the catalyst has the advantages of high activity, good stability, wide application range and low cost.

A copper-palladium-loaded mesoporous silicon carbide-based catalyst, a preparation method, and an application thereof are provided. First, a mesoporous silicon carbide material is prepared by using mesoporous silica as a hard template; subsequently, the mesoporous silicon carbide material is mixed with a copper-palladium precursor mixed solution, and dried after the solvent is completely volatilized. The dried powder is successively subjected to calcination with N.sub.2 and reduction with H.sub.2 to finally obtain the copper-palladium-loaded mesoporous silicon carbide-based catalyst. The catalyst is made into an electrode, and the nitrate in water body is catalytically reduced by electrochemical method. The preparation method of the catalyst of the present invention is simple. The catalyst can realize high-efficiency catalytic denitrification at a low metal loading amount, with high selectivity of nitrogen. Moreover, the catalyst has the advantages of high activity, good stability, wide application range and low cost.

A solid oxide electrochemical cell includes a solid oxide electrolyte, a fuel-side electrode located on a first side of the solid oxide electrolyte, and an air-side electrode located on a second side of the solid oxide electrolyte. The air-side electrode includes a strontium getter material, a current collector layer and a functional layer located between the current collector layer and the second side of the solid oxide electrolyte.

A solid oxide electrochemical cell includes a solid oxide electrolyte, a fuel-side electrode located on a first side of the solid oxide electrolyte, and an air-side electrode located on a second side of the solid oxide electrolyte. The air-side electrode includes a strontium getter material, a current collector layer and a functional layer located between the current collector layer and the second side of the solid oxide electrolyte.

Provided is a photocathode structure including: a photocathode including silicon (Si); an intermediate layer formed on the photocathode, and including a silicon oxide (SiO.sub.x); and a protective layer foiled on the intermediate layer, and including a metal oxide, wherein the intermediate layer is a tunneling barrier configured to transfer charges from the photocathode to the protective layer by an electric field applied from an outside.