A flow plate for use as an anode current collector in an electrolytic cell for the production of hydrogen from water is provided. The flow plate comprises a channel plate and a cover plate. A front face of the channel plate is provided with a flow field pattern of open-faced channels defined by depressed portions alternating with elevated portions. The cover plate made of a material that is corrosion resistant in an anodic environment of water electrolysis. The cover plate is arranged parallel on top of the channel plate and in electrical contact with the front face thereof. The cover plate is further provided with a pattern of through-going apertures alternating with closed portions, and the closed portions cover at least the elevated portions of the channel plate.

A cell stack includes a plurality of single cells, wherein each single cell includes a membrane electrode assembly having a cathode, an anode, an interposed membrane, and an anode gas diffusion layer wherein a) in a single cell, the anode gas diffusion layer and a cathode gas diffusion layer are arranged in relation to one another such that a first thickness gradient of the anode gas diffusion layer and a second thickness gradient of the cathode gas diffusion layer run opposite to one another or b) in two or more single cells, the anode gas diffusion layers are arranged in relation to one another such that an overall thickness gradient of the anode gas diffusion layers is minimized and/or wherein in two or more single cells, the cathode gas diffusion layers are arranged such that an overall thickness gradient of the cathode gas diffusion layers is minimized.

A cell stack includes a plurality of single cells, wherein each single cell includes a membrane electrode assembly having a cathode, an anode, an interposed membrane, and an anode gas diffusion layer wherein a) in a single cell, the anode gas diffusion layer and a cathode gas diffusion layer are arranged in relation to one another such that a first thickness gradient of the anode gas diffusion layer and a second thickness gradient of the cathode gas diffusion layer run opposite to one another or b) in two or more single cells, the anode gas diffusion layers are arranged in relation to one another such that an overall thickness gradient of the anode gas diffusion layers is minimized and/or wherein in two or more single cells, the cathode gas diffusion layers are arranged such that an overall thickness gradient of the cathode gas diffusion layers is minimized.

An electrolytic cell may include a cathode half-cell having a cathode, an anode half-cell having an anode, and a separator that separates the two half-cells from one another and that is permeable to electrolyte present in the half-cells during operation. At least one inlet for electrolyte is provided in a first half-cell of the two half-cells, and at least one outlet for electrolyte and no inlet for electrolyte are provided in the second half-cell such that electrolyte supplied via the at least one inlet is dischargeable via the at least one outlet after passing through the separator. A method can also be utilized to operate such an electrolytic cell. And an electrolyzer may include multiple of such electrolytic cells.

The present invention relates to a method for producing hydrogen in a polymer electrolyte membrane (PEM) water electrolyser cell. A direct electric current is applied to the water electrolyser cell. Water molecules are allowed to diffuse from a cathode compartment through a polymer electrolyte membrane into an anode compartment, to oxidize water molecules at an anode catalyst layer into protons, oxygen and electrons. The protons are allowed to migrate through a polymer electrolyte membrane into the cathode compartment and the protons are reduced at a cathode catalyst layer to produce hydrogen. The cell is supplied with water to the cathode compartment, and humidified air is supplied to the anode compartment. The invention also relates to a polymer electrolyte membrane (PEM) water electrolyser cell, a polymer electrolyte membrane (PEM) water electrolyser stack and a polymer electrolyte membrane (PEM) water electrolyser system.

The present invention relates to a method for producing hydrogen in a polymer electrolyte membrane (PEM) water electrolyser cell. A direct electric current is applied to the water electrolyser cell. Water molecules are allowed to diffuse from a cathode compartment through a polymer electrolyte membrane into an anode compartment, to oxidize water molecules at an anode catalyst layer into protons, oxygen and electrons. The protons are allowed to migrate through a polymer electrolyte membrane into the cathode compartment and the protons are reduced at a cathode catalyst layer to produce hydrogen. The cell is supplied with water to the cathode compartment, and humidified air is supplied to the anode compartment. The invention also relates to a polymer electrolyte membrane (PEM) water electrolyser cell, a polymer electrolyte membrane (PEM) water electrolyser stack and a polymer electrolyte membrane (PEM) water electrolyser system.

There is provided an electrolysis device configured to use unpurified water containing a small amount of ions of alkaline earth metal such as Ca and Mg as raw water, and to have a structure of supplying the raw water to a cathode chamber in which deposition of scale of the alkaline earth metal on the surface of a cathode provided in the cathode chamber can be prevented. The electrolysis device and the apparatus for producing electrolyzed ozone water are configured by an electrolysis cell formed in a manner that a membrane-electrode assembly is configured by a solid polymer electrolyte separation membrane formed by a cation exchange membrane, and an anode and a cathode which are respectively adhered to both surfaces of the solid polymer electrolyte separation membrane, and the membrane-electrode assembly is compressed from both surfaces thereof, and thus the solid polymer electrolyte separation membrane, the anode, and the cathode are adhered to each other. A porous conductive metallic material having flexibility and having multiple fine voids therein is used as the cathode, and scale which is mainly formed of hydroxide of alkaline earth metal is stored in fine voids in the cathode, and thus localized deposition of hydroxide of the alkaline earth metal at a contact interface between the cathode and the solid polymer electrolyte separation membrane is prevented.

Electrochemical systems comprising separator plates and the separator plates comprising a first individual plate and a second individual plate. The individual plate comprising: an electrochemically active region, at least one through-opening and a sealing bead. Conveying channels adjoin a bead flank of the sealing bead and the conveying channels connecting the through-opening and the sealing bead interior. A plurality of first weld sections connecting the two individual plates and the first weld sections extend in the direction of the first conveying channels and arranged between the first conveying channels.

Systems and methods for increasing the concentration of a desired CO.sub.x reduction reaction product are described. In some embodiments, the systems and methods include ethylene purification.

An object is to provide a methane synthesis device having as a whole a reduced size and a simplified configuration. A methane synthesis device 100 is composed of respective components from an end plate 2 at the leftmost side to an end plate 23 at the rightmost side and is compactly assembled by fastening plural bolts and nuts to bring these individual components into tightly contact with each other. The components may be divided into a Sabatier reaction unit of signs 3 to 9, a water electrolysis unit of signs 13 to 19, and other components. Hydrogen gas generated in the water electrolysis unit is mixed with carbon dioxide gas and supplied to the Sabatier reaction unit, and methane is synthesized in the Sabatier reaction unit. The size of the device is reduced as a whole and configuration is simplified by integrally stacking the water electrolysis unit, the Sabatier reaction unit, a carbon dioxide supplying unit, and a hydrogen gas supplying unit.