A catalyst system for catalyzed electrochemical reactions, in particular the electrochemical conversion of carbon dioxide into valuable chemical products, such as carboxylates and carboxylic acids, comprises a catalyst, wherein the catalyst comprises bismuth and indium. The catalyst system can be a component of a gas diffusion electrode, that can be used as the cathode electrode in an electrochemical cell.

A catalyst system for catalyzed electrochemical reactions, in particular the electrochemical conversion of carbon dioxide into valuable chemical products, such as carboxylates and carboxylic acids, comprises a catalyst, wherein the catalyst comprises bismuth and indium. The catalyst system can be a component of a gas diffusion electrode, that can be used as the cathode electrode in an electrochemical cell.

A method for making an electrocatalyst containing manganese oxide nanoparticles present on carbon obtained from Albizia procera (MnO.sub.xNPs-C) for electrochemical water oxidation. The method includes a thermal decomposition and forms a product with specific morphological variations, including crystalline structure, elemental composition, and chemical compatibility. The manganese oxide nanoparticles are well dispersed over the carbon. The amount of manganese oxide nanoparticles increases by increasing the amount of precursor. Single-phase formation of the Mn.sub.3O.sub.4, and Mn.sub.3O.sub.4 along with MnO phase occurs at low and high amount of the precursor materials, respectively. The electrocatalyst can be used for the purpose electrolytic water splitting.

A method for making an electrocatalyst containing manganese oxide nanoparticles present on carbon obtained from Albizia procera (MnO.sub.xNPs-C) for electrochemical water oxidation. The method includes a thermal decomposition and forms a product with specific morphological variations, including crystalline structure, elemental composition, and chemical compatibility. The manganese oxide nanoparticles are well dispersed over the carbon. The amount of manganese oxide nanoparticles increases by increasing the amount of precursor. Single-phase formation of the Mn.sub.3O.sub.4, and Mn.sub.3O.sub.4 along with MnO phase occurs at low and high amount of the precursor materials, respectively. The electrocatalyst can be used for the purpose electrolytic water splitting.

An electrocatalyst for producing hydrogen peroxide solution on-demand via a 2-electron electrochemical oxygen reduction reaction in an acid electrolyte is synthesized from oxygen-functionalized nanostructured carbon and noble metal particles.

An electrocatalyst for producing hydrogen peroxide solution on-demand via a 2-electron electrochemical oxygen reduction reaction in an acid electrolyte is synthesized from oxygen-functionalized nanostructured carbon and noble metal particles.

A composite material made of an amorphous (bi)metal sulfide nanoparticles directly linked, through coordinate covalent bonds, to a sulfur-containing polymer and a method of preparation of the composite material. The composite material can also be used as a catalyst for hydrogen production. Finally, a proton-exchange membrane (PEM) electrolyser and a photoelectrochemical cell, can both including the composite material.

To provide a manganese-iridium composite oxide, a manganese-iridium composite oxide and a manganese-iridium composite oxide electrode material, having high catalytic activity produced at low cost, to be used as an anode catalyst for oxygen evolution in water electrolysis, and their production methods.

A manganese-iridium composite oxide, which has an iridium metal content ratio (iridium/(manganese+indium)) of 0.1 atomic % or more and 30 atomic % or less, and has interplanar spacings of at least 0.243±0.002 nm, 0.214±0.002 nm, 0.165±0.002 nm, 0.140±0.002 nm, and a manganese-iridium composite oxide electrode material comprising an electrically conductive substrate constituted by fibers at least part of which are covered with the above manganese-iridium composite oxide.

To provide a manganese-iridium composite oxide, a manganese-iridium composite oxide and a manganese-iridium composite oxide electrode material, having high catalytic activity produced at low cost, to be used as an anode catalyst for oxygen evolution in water electrolysis, and their production methods.

A manganese-iridium composite oxide, which has an iridium metal content ratio (iridium/(manganese+indium)) of 0.1 atomic % or more and 30 atomic % or less, and has interplanar spacings of at least 0.243±0.002 nm, 0.214±0.002 nm, 0.165±0.002 nm, 0.140±0.002 nm, and a manganese-iridium composite oxide electrode material comprising an electrically conductive substrate constituted by fibers at least part of which are covered with the above manganese-iridium composite oxide.

The present invention relates to a composite that is-cost-effective, has an excellent catalytic activity, and significantly improves stability compared to a pure platinum catalyst according to the related art. Specifically, the composite according to the present invention contains a carbon support and a binary alloy consisting of platinum and an alkaline earth metal supported on the carbon support which satisfies a specific condition in a Pt 4f X-ray photoelectron spectroscopy (XPS) spectrum of the binary alloy.