Abstract: The present invention aims to provide an activated cathode enabling a long-time stable operation with hydrogen overvoltage maintained at a low value, keeping a high remaining rate of the catalyst element after a cease of operation for a short-circuiting and after an electrolysis operation at a high current density, restricting catalyst loss to a little, and having a strong resistance to contamination caused by electrolyte impurity elements. The present invention relates to a cathode for hydrogen evolution with a catalyst layer formed on the cathode substrate, having, at least, three elements comprising platinum, cerium and palladium, as essential element, in a state of metal, metal oxide, or hydroxide, contained, where the mole fraction of respective element being x, y, and z, within a range of 5 mol %?x?90 mol %, 5 mol %?y?55 mol %, 5 mol %?z?65 mol %.

Abstract: The present invention aims to provide an activated cathode enabling a long-time stable operation with hydrogen overvoltage maintained at a low value, keeping a high remaining rate of the catalyst element after a cease of operation for a short-circuiting and after an electrolysis operation at a high current density, restricting catalyst loss to a little, and having a strong resistance to contamination caused by electrolyte impurity elements. The present invention relates to a cathode for hydrogen evolution with a catalyst layer formed on the cathode substrate, having, at least, three elements comprising platinum, cerium and palladium, as essential element, in a state of metal, metal oxide, or hydroxide, contained, where the mole fraction of respective element being x, y, and z, within a range of 5 mol %?x?90 mol %, 5 mol %?y?55 mol %, 5 mol %?z?65 mol %.

Abstract: The present invention provides an electrode for generation of hydrogen comprising: a conductive substrate; a catalytic layer formed on the conductive substrate and containing at least one platinum group metal selected from the group consisting of Pt, Ir, Ru, Pd and Rh; and a hydrogen adsorption layer formed on the catalytic layer. The present invention also provides an electrode for generation of hydrogen comprising: a conductive substrate, a catalytic layer formed on the conductive substrate and containing: at least one platinum group metal selected from the group consisting of Pt, Ir, Ru, Pd and Rh and/or at least one oxide of said platinum group metals; and at least one metal selected from the group consisting of lanthanum series metals, valve metals, iron series metals and silver and/or at least one oxide of said metals; and a hydrogen adsorption layer formed on the catalytic layer.

Abstract: The present invention provides a cathode for hydrogen generation comprising a cathode substrate having provided thereon a catalytic layer, wherein the catalytic layer contains at least three components of platinum, cerium and lanthanum in amounts of 50 to 98 mol %, 1 to 49 mol % and 1 to 49 mol %, respectively, in the form of metal, metal oxide or metal hydroxide.

Abstract: The present invention provides a cathode for hydrogen generation comprising a cathode substrate having provided thereon a catalytic layer, wherein the catalytic layer contains at least three components of platinum, cerium and lanthanum in amounts of 50 to 98 mol %, 1 to 49 mol % and 1 to 49 mol %, respectively, in the form of metal, metal oxide or metal hydroxide.

Abstract: The present invention provides an electrode for generation of hydrogen comprising: a conductive substrate; a catalytic layer formed on the conductive substrate and containing at least one platinum group metal selected from the group consisting of Pt, Ir, Ru, Pd and Rh; and a hydrogen adsorption layer formed on the catalytic layer. The present invention also provides an electrode for generation of hydrogen comprising: a conductive substrate, a catalytic layer formed on the conductive substrate and containing: at least one platinum group metal selected from the group consisting of Pt, Ir, Ru, Pd and Rh and/or at least one oxide of said platinum group metals; and at least one metal selected from the group consisting of lanthanum series metals, valve metals, iron series metals and silver and/or at least one oxide of said metals; and a hydrogen adsorption layer formed on the catalytic layer.

Abstract: The present invention provides an electrolysis cell for synthesizing a perchloric acid compound, the electrolysis cell having: a feedstock solution containing a chloride or a chloric acid compound; a cathode; and an anode having an electroconductive diamond as an anode substance, the anode electrolytically oxidizing the chloride or the chloric acid compound to synthesize the perchloric acid compound, and a method for electrolytically synthesizing a perchloric acid compound.

Abstract: Highly active hydrogen evolving cathode using a platinum group metal catalyst in an amount smaller than that used in the conventional hydrogen evolving cathode. The hydrogen evolving cathode includes a conductive substrate, and a catalyst layer comprising at least one selected from the group consisting of silver and a silver oxide compound, and at least one selected from the group consisting of a platinum group metal, a platinum group metal oxide and a platinum group metal hydroxide, formed on a surface of the conductive substrate.

Abstract: A diamond electrode having a prolonged life by combining a conventional diamond electrode having a relatively short life with other components is provided. A diamond electrode for electrolysis includes an electrode substrate, at least the surface of which comprises Magneli phase titanium oxide, and conductive diamond supported as an electrode catalyst on a surface of the electrode. The electrode catalyst may contain a titanium oxide powder. Magneli phase titanium oxide improves conductivity without forming a stable oxide layer on the substrate surface.

Abstract: Highly active hydrogen evolving cathode using a platinum group metal catalyst in an amount smaller than that used in the conventional hydrogen evolving cathode. The hydrogen evolving cathode includes a conductive substrate, and a catalyst layer comprising at least one selected from the group consisting of silver and a silver oxide compound, and at least one selected from the group consisting of a platinum group metal, a platinum group metal oxide and a platinum group metal hydroxide, formed on a surface of the conductive substrate.

Abstract: A diamond electrode having a prolonged life by combining a conventional diamond electrode having a relatively short life with other components is provided. A diamond electrode for electrolysis includes an electrode substrate, at least the surface of which comprises Magneli phase titanium oxide, and conductive diamond supported as an electrode catalyst on a surface of the electrode. The electrode catalyst may contain a titanium oxide powder. Magneli phase titanium oxide improves conductivity without forming a stable oxide layer on the substrate surface.

Abstract: An electrochemical treating apparatus comprising an electrolytic cell comprising an anode and a cathode spaced apart from the anode, the anode including an electrode material made of diamond and the cathode including an electrode material made of diamond. Also disclosed is an electrochemical treating method for electrochemically decomposing a substance contained in a gas or solution, which comprises introducing a gas or solution containing a substance to be treated into the electrolytic cell, passing an electric current through the electrolytic cell, and recovering a treated gas or solution. In a preferred embodiment, the electrolytic cell comprises an anode including an electrode material made of diamond, a cathode including an electrode material made of diamond and an ion exchange resin or an ion exchange membrane as an electrolyte disposed between the anode and the cathode.

Abstract: An activated cathode comprising an electrically conductive substrate, an interlayer comprising a nickel oxide formed on the surface of the electrically conductive substrate, and a catalyst layer containing at least one lanthanum component selected from oxides and hydroxides of lanthanum metals and at least one platinum component selected from platinum metals and silver and oxides and hydroxides thereof formed on the interlayer. A process for the preparation of an activated cathode is also disclosed which comprises forming an interlayer comprising a nickel oxide on the surface of an electrically conductive substrate, and then forming a catalyst layer containing at least one lanthanum component selected from oxides and hydroxides of lanthanum metals and at least one platinum. component selected from platinum metals and silver and oxides and hydroxides thereof on the surface of the interlayer.

Abstract: An electrode adapted for chromium plating from trivalent chromium baths which comprises a conductive base, an electrode material layer comprising iridium oxide formed thereon, and a porous layer formed on the surface of the electrode material layer. The porous can comprise an oxide containing at least one element selected from the group consisting of silicon, molybdenum, titanium, tantalum, zirconium, and tungsten. Use of this electrode for chromium plating reduces the oxidation of trivalent chromium into hexavalent chromium.