The present disclosure broadly relates to a process for preparing aqueous solutions of vanadium sulfates or aqueous solutions of transition metal sulfates. More specifically, but not exclusively, the present disclosure relates to a direct electrochemical process in which a suspension, obtained by slurrying transition metals oxides such as oxides of vanadium, oxides of iron, oxides of cobalt, oxides of nickel, oxides of chromium, oxides of manganese, oxides of titanium, oxides of cerium, oxides of praseodymium, oxides of europium, oxides of terbium, oxides of uranium, oxides of plutonium, or their mixtures thereof with sulfuric acid as carrier fluid, is reduced electrochemically inside the cathode compartment of an electrolyzer to produce an aqueous solution of vanadium sulfates or of transition metal sulfates. Simultaneously, oxidizing co-products are produced in the anode compartment.

The application discloses an electrode having polarity capable of being reversed and use thereof. The electrode includes a substrate comprising a metal or an alloy thereof; an intermediate layer arranged on the substrate and comprising a platinum group metal and a platinum group metal oxide; and a catalytic layer arranged on the intermediate layer and comprising a mixed metal oxide. The electrode may be used as an electrode for electrolysis, electrodialysis or electroplating. The electrode can simultaneously meet the working environment requirements of the cathode and the anode, which improves the environmental tolerance and realizes the protection of the substrate; and can carry out polarity reversal to clean deposits on the surface of the electrode quickly and efficiently.

An advanced manufactured electrochemical reactor to convert air (N.sub.2+O.sub.2) to nitric acid (HNO.sub.3) and ammonia (NH.sub.3). The electrochemical reactor platform can be tailored via advanced manufacturing to improve activity, selectivity, energy efficiency and stability of the reactions.

An electrode suitable for use as a cathode for the development of hydrogen in industrial electrolytic processes, equipped with a catalytic coating having an external layer containing ruthenium and selenium; and a method for the production of the same.

An electrode suitable for use as a cathode for the development of hydrogen in industrial electrolytic processes, equipped with a catalytic coating having an external layer containing ruthenium and selenium; and a method for the production of the same.

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.

In a case where an alkali aqueous solution is used as an electrolyte, provided are an oxygen catalyst excellent in catalytic activity and composition stability, an electrode having high activity and stability using this oxygen catalyst, and an electrochemical measurement method that can evaluate the catalytic activity of the oxygen catalyst alone. The oxygen catalyst is an oxide having peaks at positions of 2θ=30.07°±1.00°, 34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuKα ray, and having constituent elements of bismuth, ruthenium, sodium, and oxygen. An atom ratio O/Bi of oxygen to bismuth and an atom ratio O/Ru of oxygen to ruthenium are both more than 3.5.

Systems and methods for manufacturing and use of a two layer coated electrode are provided. The two layer coated electrode may comprise a substrate, a first coating layer, and a second coating layer. The first coating layer may comprise a mixture of iridium oxide and tin oxide, and the second coating layer may comprise a mixture of iridium oxide and tantalum oxide. The electrode may be used in, for example, an electrolytic cell.

Provided is a cathode for electrolysis comprising a conductive substrate and a Ru element-containing catalyst layer on the conductive substrate, wherein in the catalyst layer, the ratio of the maximum intensity of the Ru 3d 5/2 peak appearing between 281.4 eV and 282.4 eV to the maximum intensity of the Ru 3d 5/2 peak appearing between 280.0 eV and 281.0 eV, in an X-ray photoelectron spectroscopic measurement is 0.45 or more.

Provided are an electrode, an electrolysis cell, and an electrochemical analyzer that improve the long-term stability of analysis data. A working electrode, a counter electrode, and reference electrode are disposed in an electrolysis cell. The working electrode is obtained by forming a lead wire in a composite material having platinum or a platinum alloy as a base material, in which a metal oxide is dispersed, or in a laminated material obtained by laminating a valve metal and platinum such that the cross sectional crystal texture in the thickness direction of the platinum is formed in layers and the thickness of each layer of the platinum is 5 micrometers or less. The metal oxide is selected from among zirconium oxide, tantalum oxide, and niobium oxide, and the metal oxide content of the platinum or the platinum alloy is 0.005 to 1 wt % in terms of the zirconium, tantalum, or niobium metal.