Fluoride-containing nickel iron oxyhydroxide electrocatalysts for use as anodes in anion exchange membrane electrolyzers for generating hydrogen gas.

Described herein are salt-splitting electrolysis systems, which comprise flow electrodes, and methods of operating such systems. Specifically, the flow electrodes comprise active particles (suspended in a solvent) with catalysts. These catalysts are configured to react with either cations or anions, provided in a feed stream. The flow electrodes allow using the same system for different feed streams, e.g., by flowing different types of electrodes through the system. Furthermore, the flow electrodes allow in-situ catalyst reconditioning. For example, the active particles can be flown from the current collectors to respective recovery devices where the particles are discharged or subjected to a reverse potential. The active particles can be conductive and provide more desirable electrical field distribution between the current collectors resulting in greater ionic mobility. Finally, the active particles concentrate ions around the particles thereby providing a higher concentration gradient through separating structures, which enclose the feed stream.

Described herein are salt-splitting electrolysis systems, which comprise flow electrodes, and methods of operating such systems. Specifically, the flow electrodes comprise active particles (suspended in a solvent) with catalysts. These catalysts are configured to react with either cations or anions, provided in a feed stream. The flow electrodes allow using the same system for different feed streams, e.g., by flowing different types of electrodes through the system. Furthermore, the flow electrodes allow in-situ catalyst reconditioning. For example, the active particles can be flown from the current collectors to respective recovery devices where the particles are discharged or subjected to a reverse potential. The active particles can be conductive and provide more desirable electrical field distribution between the current collectors resulting in greater ionic mobility. Finally, the active particles concentrate ions around the particles thereby providing a higher concentration gradient through separating structures, which enclose the feed stream.

Disclosed herein is a method for fabricating a membrane-electrode assembly for PEM water electrolysis, whereby the electrode layer can be improved in electrical conductivity. Specifically, a membrane-electrode assembly for PEM water electrolysis, comprising: a polymer electrolyte membrane; an anode disposed on one surface of the polymer electrolyte membrane and containing an anode catalyst; a cathode disposed on another surface of the polymer electrolyte membrane and containing a cathode catalyst; and a platinum layer disposed on the anode, and a fabrication method therefor are provided.

Disclosed herein is a method for fabricating a membrane-electrode assembly for PEM water electrolysis, whereby the electrode layer can be improved in electrical conductivity. Specifically, a membrane-electrode assembly for PEM water electrolysis, comprising: a polymer electrolyte membrane; an anode disposed on one surface of the polymer electrolyte membrane and containing an anode catalyst; a cathode disposed on another surface of the polymer electrolyte membrane and containing a cathode catalyst; and a platinum layer disposed on the anode, and a fabrication method therefor are provided.

A tandem electrode for electrochemically reducing carbon dioxide is described. The electrode includes a first distinct catalyst layer and a second distinct catalyst layer. The first distinct catalyst layer is made of a C.sub.1 hydrocarbon or C.sub.2+ product selective catalyst and the second distinct catalyst layer is comprised of a CO selective catalyst. In one embodiment, the second distinct catalyst layer is concentrated at one end of the tandem electrode. In another embodiment, the tandem electrode also includes a microporous layer and a substrate layer.

A tandem electrode for electrochemically reducing carbon dioxide is described. The electrode includes a first distinct catalyst layer and a second distinct catalyst layer. The first distinct catalyst layer is made of a C.sub.1 hydrocarbon or C.sub.2+ product selective catalyst and the second distinct catalyst layer is comprised of a CO selective catalyst. In one embodiment, the second distinct catalyst layer is concentrated at one end of the tandem electrode. In another embodiment, the tandem electrode also includes a microporous layer and a substrate layer.

A light-driven fuel cell includes a cathode, an anode, and a proton-permeable membrane between the anode and the cathode. The anode includes a photocatalyst for anaerobic methane oxidation reaction, and when the anode is supplied with methane and water and is irradiated with light, methanol, protons and electrons are generated by anaerobic methane oxidation reaction from the methane and the water supplied to the anode; the protons pass through the proton-permeable membrane and move to the cathode; and the electrons move to the cathode via an external circuit. The cathode includes a photocatalyst for aerobic methane oxidation reaction, and when the cathode is supplied with methane and oxygen and is irradiated with light, methanol and water are generated by aerobic methane oxidation reaction from the methane and the oxygen supplied to the cathode and the protons and the electrons moved from the anode.

A light-driven fuel cell includes a cathode, an anode, and a proton-permeable membrane between the anode and the cathode. The anode includes a photocatalyst for anaerobic methane oxidation reaction, and when the anode is supplied with methane and water and is irradiated with light, methanol, protons and electrons are generated by anaerobic methane oxidation reaction from the methane and the water supplied to the anode; the protons pass through the proton-permeable membrane and move to the cathode; and the electrons move to the cathode via an external circuit. The cathode includes a photocatalyst for aerobic methane oxidation reaction, and when the cathode is supplied with methane and oxygen and is irradiated with light, methanol and water are generated by aerobic methane oxidation reaction from the methane and the oxygen supplied to the cathode and the protons and the electrons moved from the anode.

A method of ammonia synthesis is described that includes contacting a nitrogen gas-containing plasma with an aqueous solution, thereby forming ammonia from the nitrogen gas and water. The nitrogen gas-containing plasma is present in an electrochemical cell. The electrochemical cell includes a container including an acidic liquid electrolyte. The electrochemical cell also includes a source of nitrogen gas, a metal electrode at least partially immersed in the electrolyte, a metal tube electrode spaced apart from a surface of the electrolyte by a predetermined spacing. The electrochemical cell is configured to provide a plasma spanning the predetermined space from the metal tube electrode to contact the surface of the electrolyte when power is applied to the metal tube electrode.