Herein discussed is a method of producing hydrogen comprising introducing a first stream comprising a fuel to an electrochemical (EC) reactor having a mixed-conducting membrane, introducing a second stream comprising water to the reactor, reducing the water in the second stream to produce hydrogen, and recycling at least portion of the produced hydrogen to the first stream, wherein the membrane comprises an electronically conducting phase and an ionically conducting phase; and wherein the first stream and the second stream do not come in contact with each other in the reactor.

Herein discussed is a method of producing hydrogen comprising introducing a first stream comprising a fuel to an electrochemical (EC) reactor having a mixed-conducting membrane, introducing a second stream comprising water to the reactor, reducing the water in the second stream to produce hydrogen, and recycling at least portion of the produced hydrogen to the first stream, wherein the membrane comprises an electronically conducting phase and an ionically conducting phase; and wherein the first stream and the second stream do not come in contact with each other in the reactor.

An electrolyzer stack is configured for high-speed manufacturing and assembly of a plurality of scalable electrolysis cells. Each cell comprises a plurality of water windows configured to maintain a pressure loss, temperature rise and/or oxygen outlet volume fraction below predetermined thresholds. Repeating components of the cells are configured based on a desired roll web width for production and a stack compression system is configured to enable a variable quantity and variable area of said repeating cells in a single stack. A high-speed manufacturing system is configured to produce scalable cells and assemble scalable stacks at rates in excess of 1,000 MW-class stacks per year.

The present disclosure relates to a transition metal-doped nickel phosphide nanostructure, a method for preparing the same, and a catalyst for electrochemical water decomposition including the transition metal-doped nickel phosphide nanostructure. More specifically, a transition metal-doped nickel phosphide nanostructure can be prepared by converting a zinc oxide nanostructure grown on a substrate vertically by hydrothermal synthesis to a transition metal-doped nickel oxide nanostructure by cation exchange and then phosphorizing the nickel oxide. The transition metal-doped nickel phosphide nanostructure of the present disclosure is advantageous in that it has superior catalytic activity and conductivity due to large surface area. In addition, when used as a catalyst for water decomposition under an alkaline condition, it has a low overvoltage and can have excellent catalytic activity for hydrogen evolution reaction or oxygen evolution reaction.

The present disclosure relates to a transition metal-doped nickel phosphide nanostructure, a method for preparing the same, and a catalyst for electrochemical water decomposition including the transition metal-doped nickel phosphide nanostructure. More specifically, a transition metal-doped nickel phosphide nanostructure can be prepared by converting a zinc oxide nanostructure grown on a substrate vertically by hydrothermal synthesis to a transition metal-doped nickel oxide nanostructure by cation exchange and then phosphorizing the nickel oxide. The transition metal-doped nickel phosphide nanostructure of the present disclosure is advantageous in that it has superior catalytic activity and conductivity due to large surface area. In addition, when used as a catalyst for water decomposition under an alkaline condition, it has a low overvoltage and can have excellent catalytic activity for hydrogen evolution reaction or oxygen evolution reaction.

A coral reef-like nickel phosphide-tungsten oxide nanocomposite is disclosed. The coral reef-like nickel phosphide-tungsten oxide nanocomposite has a structure in which algae-like transition metal-doped nickel phosphide nanosheets are deposited on coral-like tungsten oxide nanostructures grown vertically on a substrate. This structure allows the coral reef-like nickel phosphide-tungsten oxide nanocomposite to have a large surface area, which leads to a significant increase in the number of catalytic active sites, and ensures high conductivity and electrochemical stability of the coral reef-like nickel phosphide-tungsten oxide nanocomposite. Due to these advantages, the coral reef-like nickel phosphide-tungsten oxide nanocomposite has a low overpotential and superior hydrogen evolution reaction or oxygen evolution reaction efficiency when applied to a water splitting catalyst under alkaline conditions. Also disclosed are a method for preparing the coral reef-like nickel phosphide-tungsten oxide nanocomposite and a catalyst for electrochemical water splitting including the coral reef-like nickel phosphide-tungsten oxide nanocomposite.

A coral reef-like nickel phosphide-tungsten oxide nanocomposite is disclosed. The coral reef-like nickel phosphide-tungsten oxide nanocomposite has a structure in which algae-like transition metal-doped nickel phosphide nanosheets are deposited on coral-like tungsten oxide nanostructures grown vertically on a substrate. This structure allows the coral reef-like nickel phosphide-tungsten oxide nanocomposite to have a large surface area, which leads to a significant increase in the number of catalytic active sites, and ensures high conductivity and electrochemical stability of the coral reef-like nickel phosphide-tungsten oxide nanocomposite. Due to these advantages, the coral reef-like nickel phosphide-tungsten oxide nanocomposite has a low overpotential and superior hydrogen evolution reaction or oxygen evolution reaction efficiency when applied to a water splitting catalyst under alkaline conditions. Also disclosed are a method for preparing the coral reef-like nickel phosphide-tungsten oxide nanocomposite and a catalyst for electrochemical water splitting including the coral reef-like nickel phosphide-tungsten oxide nanocomposite.

A system for high-temperature reversible electrolysis of water, characterised in that it includes: a high-temperature reversible electrolyser, configured to operate in SOEC (solid oxide electrolyser cell) mode to produce hydrogen and store electricity, and/or in SOFC (solid oxide fuel cell) mode to withdraw hydrogen and produce electricity; a hydride tank, thermally coupled with the reversible electrolyser, the system being configured to allow the recovery of heat released by the hydride tank during hydrogen absorption in order to produce pressurised steam intended for entering the reversible electrolyser in SOEC mode, and to allow the recovery of heat released by the one or more outgoing streams from the reversible electrolyser in SOFC mode so as to allow the desorption of hydrogen from the hydride tank.

A system for high-temperature reversible electrolysis of water, characterised in that it includes: a high-temperature reversible electrolyser, configured to operate in SOEC (solid oxide electrolyser cell) mode to produce hydrogen and store electricity, and/or in SOFC (solid oxide fuel cell) mode to withdraw hydrogen and produce electricity; a hydride tank, thermally coupled with the reversible electrolyser, the system being configured to allow the recovery of heat released by the hydride tank during hydrogen absorption in order to produce pressurised steam intended for entering the reversible electrolyser in SOEC mode, and to allow the recovery of heat released by the one or more outgoing streams from the reversible electrolyser in SOFC mode so as to allow the desorption of hydrogen from the hydride tank.

An electrolyzer cell comprises a first half cell comprising a housing at least partially enclosing a cell interior, a first electrode coated with a first catalyst coating, wherein the first electrode is coupled to the housing in the cell interior without welding, a second electrode coupled to the housing in the cell interior without welding, and a separator positioned between the first electrode and the second electrode, wherein a voltage is applied between the first electrode and the second electrode.