Abstract: In one embodiment, in a diagnosis method of an electrolysis unit, an impedance of the electrolysis unit is measured in each of a first frequency range and a second frequency range lower in frequency than the first frequency range. In the diagnosis method, a resistance value of each of a first resistance component in which influence on the impedance becomes dominant in a first frequency range and a second resistance component in which influence on the impedance becomes dominant in a second frequency range is calculated based on measurement results of the impedance, and degradation and operation of the electrolysis unit are determined based at least on a calculation result of each of the resistance values of the first resistance component and the second resistance component.

Abstract: According to the embodiment, a bonded body includes a ceramic substrate, a copper plate. A bonding layer is located on at least one surface of the ceramic substrate. The bonding layer bonds the ceramic substrate and the copper plate. The bonding layer includes a Ti reaction layer including titanium nitride or titanium oxide as a major component, and a plurality of first alloys positioned between the Ti reaction layer and the copper plate. Each of the plurality of first alloys includes at least one selected from a Cu—Sn alloy and a Cu—In alloy. The first alloys have mutually-different Sn concentrations or In concentrations. According to the embodiment, a warp amount can be reduced. A heating rate and a cooling rate in the bonding process can be increased. According to the embodiment, a silicon nitride substrate is favorable for the ceramic substrate.

Abstract: A bonded body according to an embodiment includes a ceramic substrate, a copper plate, and a bonding layer. The bonding layer is located on at least one surface of the ceramic substrate and bonds the ceramic substrate and the copper plate. The bonding layer includes Ag and Ti. The copper plate includes a first region, a second region, and a third region. The first region is separated from the bonding layer in a thickness direction. The second region is located between the bonding layer and the first region and has a higher Ag concentration than the first region. The third region is located between the bonding layer and the second region and has a lower Ag concentration than the second region.

Abstract: A membrane electrode assembly includes: a cathode that is arranged to be in contact with a reducible substance to be supplied as a raw material gas and reduces the reducible substance; an anode that is arranged to be in contact with an electrolytic solution containing an oxidizable substance and oxidizes the oxidizable substance; and a diaphragm separating the cathode and the anode. The anode includes a porous substrate having a first surface facing on the diaphragm and a second surface opposite to the first surface, and an oxidation catalyst on the porous substrate. An average surface roughness of the first surface is 0.1 ?m or more and 17.0 ?m or less.

Abstract: A membrane electrode assembly includes: a cathode that is arranged to be in contact with a reducible substance and reduces the reducible substance; an anode that is arranged to be in contact with an electrolytic solution containing an oxidizable substance and oxidizes the oxidizable substance; a diaphragm separating the cathode and the anode; and a layer that is provided between the anode and the diaphragm, has an inorganic material, and reduces a surface unevenness of the anode. An average pore size of the layer is smaller than an average pore size of the anode.

Abstract: An electrolysis cell includes: a cathode having a reduction catalyst that promotes a reduction reaction of reducing a reducible material to produce a reduction product, and the reducible material being carbon dioxide or nitrogen; an anode having an oxidation catalyst that promotes an oxidation reaction of oxidizing water to produce oxygen; a diaphragm provided between the cathode and the anode; a cathode flow path facing on the cathode and through which a gas of the reduction material flows; an anode flow path facing on the anode and through which an electrolytic solution containing the water flows; and a chemical species between the anode flow path and the diaphragm, the chemical species being configured to decompose, capture, or inactivate an active oxygen species.

Abstract: The electrochemical reaction device includes: an electrochemical reaction structure including a cathode, an anode, a diaphragm having a first surface on the cathode and a second surface on the anode, a cathode flow path, and an anode flow path; a first flow path through which a first fluid containing a reducible material to the cathode flow path flows; a second flow path through which a second fluid containing water to the anode flow path flows; a third flow path through which a third fluid containing the reduction product from the cathode flow path flows; and a fourth flow path through which a fourth fluid containing water and oxygen from the anode flow path flows. The diaphragm has concentration gradient in which a concentration of a chemical species decreases from the second surface to the first surface, the chemical species being configured to decompose, capture, or inactivate an active oxygen specie.

Abstract: A separator according to an embodiment includes a flow channel comprising one or more flow-channel grooves provided between flow-channel walls. One or more protrusions are provided on the flow-channel walls.

Abstract: A method of operating an electrochemical reaction device, includes controlling an electrolytic unit during each of a startup process, an operation process, and a shutdown process so that a first time-averaged pressure at a first position in the cathode space and closer to an inlet of a cathode space than an outlet of the cathode space is equal to or higher than a second time-averaged pressure at a second position in an anode space and opposite the first position with a diaphragm therebetween, and a third time-averaged pressure at a third position in the cathode space and closer to the outlet than the inlet is equal to or higher than a fourth time-averaged pressure at a fourth position in the anode space and opposite the third position with the diaphragm therebetween.

Abstract: A bonded body according to an embodiment comprises a ceramic substrate, a copper plate, and a bonding layer provided on at least one surface of the ceramic substrate and bonding the ceramic substrate and the copper plate, in which the bonding layer contains Cu, Ti, and a first element being one or two selected from Sn and In, and the bonding layer includes a Ti-rich region in which a ratio (MTi/ME1) of a mass MTi of Ti to a mass ME1 of the first element being 0.5 or more and a Ti-poor region in which the ratio (MTi/ME1) being 0.1 or less.

Abstract: An electrochemical reaction device includes: an electrochemical reaction structure including a cathode to reduce carbon dioxide to produce a carbon compound, an anode to oxidize water to produce oxygen, a diaphragm therebetween, a cathode flow path on the cathode, and an anode flow path on the anode; a first flow path through which a first fluid to the cathode flow path flows; a second flow path through which a second fluid to the anode flow path flows; a third flow path through which a third fluid from the cathode flow path flows; a fourth flow path through which a fourth fluid from the anode flow path flows; and a gas-liquid separator in or on the anode flow path and to separate a gas containing the oxygen from a fifth fluid containing the water and the oxygen through the anode flow path.

Abstract: According to one embodiment, when a DSC curve is measured using a differential scanning calorimeter (DSC) for a brazing material for bonding a ceramic substrate and a metal plate, the brazing material has an endothermic peak within a range of not less than 550° C. and not more than 700° C. in a heating process. The brazing material favorably includes Ag, Cu, and Ti. The brazing material favorably has not less than two of the endothermic peaks within a range of not less than 550° C. and not more than 650° C. in the heating process.

Abstract: A bonded body includes a ceramic substrate, a copper plate, and a bonding layer provided on at least one surface of the ceramic substrate and bonding the ceramic substrate and the copper plate, in which the bonding layer contains Ag, Cu, Ti, and a first element being one or two selected from Sn and In, a Ti alloy of Ti and at least one selected from Ag, Cu, Sn, and In existing at a bonding boundary between the copper plate and the bonding layer, and the Ti alloy existing over not less than 30% per a length of 30 ?m at the bonding boundary.

Abstract: An electrolysis device includes: a first electrolysis cell to reduce a reducible material and oxidize an oxidizable material; a second electrolysis cell to reduce the reducible material and oxidize the oxidizable material; a first supply source to supply a first fluid containing gas of the reducible material to the cells; a second supply source to supply a second fluid containing liquid of the oxidizable material to the cells; and at least one power supply to supply a first and a second power supply current to the first and the second electrolysis cell respectively. The at least one power supply can set values of the first and second power supply currents so that a current density of current flowing through the second electrolysis cell when reducing the reducible material is higher than a current density of current flowing through the first electrolysis cell when reducing the reducible material.

Abstract: A bonded body includes a ceramic substrate and a copper plate, in which the copper plate is bonded to the ceramic substrate via a bonding layer, the copper plate includes a surface perpendicular to a direction in which the ceramic substrate and the copper plate are bonded, and a number percentage of copper crystal grains having major diameters greater than 400 ?m in three 5 mm×5 mm regions included in the surface is not less than 0% and not more than 5%. The bonding temperature is favorably not more than 800° C. The number percentage of the copper crystal grains having major diameters greater than 400 ?m is favorably not more than 1%.

Abstract: A bonded body includes a ceramic substrate and a copper plate, in which the copper plate is bonded to the ceramic substrate via a bonding layer, the copper plate includes a surface perpendicular to a direction in which the ceramic substrate and the copper plate are bonded, and a number percentage of copper crystal grains having major diameters greater than 400 ?m in three 5 mm×5 mm regions included in the surface is not less than 0% and not more than 5%. The bonding temperature is favorably not more than 800° C. The number percentage of the copper crystal grains having major diameters greater than 400 ?m is favorably not more than 1%.

Abstract: An electrolysis cell 20 includes: a cathode 31 to reduce a reducible gas; an anode 41 to oxidize an oxidizable substance in an electrolytic solution, the cathode 41 containing titanium; and a separator 50 separating the cathode 31 from the anode 41. The separator 50 includes a porous membrane. The porous membrane gives a pore size distribution defined by a graph having a horizontal axis and a vertical axis, the horizontal axis representing pore sizes of through holes of the porous membrane, the pore sizes being determined by using a porometer, the vertical axis representing a pore size flow distribution of pore volumes corresponding to the pore sizes, and the pore size distribution having a peak top in a range of not less than 0.01 ?m nor more than 0.3 ?m. The porous membrane has an ISO air permeance of not less than 0.8 ?m/Pa·s nor more than 150 ?m/Pa·s.

Abstract: A bonded body according to an embodiment includes a ceramic substrate, a copper plate, and a bonding layer that is located on at least one surface of the ceramic substrate and bonds the ceramic substrate and the copper plate. The bonding layer includes titanium. The bonding layer includes first and second regions; the first region includes a layer including titanium as a major component; the layer is formed at an interface of the bonding layer with the ceramic substrate; and the second region is positioned between the first region and the copper plate. The bonded body has a ratio M1/M2 of a titanium concentration M1 at % in the first region and a titanium concentration M2 at % in the second region that is not less than 0.1 and not more than 5 when the Ti concentrations are measured by EDX respectively in measurement regions in the first and second regions.

Abstract: A carbon dioxide electrolytic device of an embodiment includes: an electrolysis cell including a cathode to reduce carbon dioxide, an anode to oxidize water or hydroxide ion and having a base containing titanium, a cathode flow path to supply carbon dioxide to the cathode, an anode flow path to supply an electrolytic solution containing water to the anode, and a separator to separate the anode and the cathode; a gas supply unit to supply carbon dioxide to the cathode flow path; at least either of a humidifier to humidify carbon dioxide supplied to the cathode flow path by using a humidification water, and a liquid pouring part to add the humidification water to the carbon dioxide; and an electrolytic solution supply unit to supply the electrolytic solution to the anode flow path. At least one of the electrolytic solution, the humidification water, and the supplied gas contains an oxidant.

Abstract: A bonded body according to an embodiment includes a substrate, a metal member, and a bonding layer. The bonding layer is provided between the substrate and the metal member. The bonding layer includes a first particle including carbon, a first region including a metal, and a second region including titanium. The second region is provided between the first particle and the first region. A concentration of titanium in the second region is greater than a concentration of titanium in the first region.