The invention relates to a process and devices for reducing impurities in molten salts, a molten salt being purified in an electrochemical process by applying a voltage between two electrodes. According to the invention, the voltage is varied so that in different phases different electrodes act as cathode or anode.

The invention relates to an electrode material, preferably an inert anode material comprising at least a metal core and a cermet material, characterized in that: said metal core contains at least one nickel (Ni) and iron (Fe) alloy, said cermet material comprises at least as percentages by weight: 45 to 80% of a nickel ferrite oxide phase (2) of composition Ni.sub.xFe.sub.yM.sub.zO.sub.4 with 0.60 ≤x≤0.90; 1.90≤y≤2.40; 0.00≤z≤0.20 and M being a metal selected from aluminum (Al), cobalt (Co), chromium (Cr), manganese (Mn), titanium (Ti), zirconium (Zr), tin (Sn), vanadium (V), niobium (Nb), tantalum (Ta) and hafnium (Hf) or being a combination of these metals, 15 to 45% of a metallic phase (1) comprising at least one alloy of nickel and copper.

A gas diffusion electrode may be provided comprising an electron conducting layer with a first side and an opposite second side, wherein the first side is provided with a microstructuring, wherein the gas diffusion electrode additionally has a hydrophobic membrane with a first side and an opposite second side, wherein the second side of the membrane is arranged on the first side of the electron conducting layer. A battery or an accumulator or an electrolyser or a galvanic cell may be provided with a gas diffusion electrode of this type.

A gas diffusion electrode may be provided comprising an electron conducting layer with a first side and an opposite second side, wherein the first side is provided with a microstructuring, wherein the gas diffusion electrode additionally has a hydrophobic membrane with a first side and an opposite second side, wherein the second side of the membrane is arranged on the first side of the electron conducting layer. A battery or an accumulator or an electrolyser or a galvanic cell may be provided with a gas diffusion electrode of this type.

There is provided a method of electrochemically reducing multiple metal oxide pellets simultaneously, the method comprising: contacting an anode and a cathode with multiple metal oxide pellets with an electrolyte, wherein the multiple metal oxide pellets are secured to the cathode; and applying an electrical potential between the anode and the cathode to reduce multiple metal oxides comprised in the multiple metal oxide pellets to its respective metals. There is also provided an electrochemical cell for electrochemically reducing multiple metal oxide pellets simultaneously.

An electrode (10) is disclosed. The electrode (10) comprises an electrode substrate (20). A layer of TiO.sub.x (30, 40) with a total thickness in the range of between 40-200 μm is present on at least one surface of the electrode substrate (20) and a porosity of layer of TiO.sub.x (30, 40) is below 15%. An electro-catalytic layer (50) comprising oxides of ruthenium and cerium according comprising at least 50 molar % ruthenium oxides is present on layer of TiO.sub.x (30, 40) and wherein x is in the range 1-2 for the layer of TiO.sub.x. A process for the manufacture of the electrode (10) is disclosed as are uses thereof.

An electrode (10) is disclosed. The electrode (10) comprises an electrode substrate (20). A layer of TiO.sub.x (30, 40) with a total thickness in the range of between 40-200 μm is present on at least one surface of the electrode substrate (20) and a porosity of layer of TiO.sub.x (30, 40) is below 15%. An electro-catalytic layer (50) comprising oxides of ruthenium and cerium according comprising at least 50 molar % ruthenium oxides is present on layer of TiO.sub.x (30, 40) and wherein x is in the range 1-2 for the layer of TiO.sub.x. A process for the manufacture of the electrode (10) is disclosed as are uses thereof.

A porous transparent electrode is formed where a film comprising of semiconducting nanoparticles is decorated with polyoxometalates (POMs) bonded to their surfaces. The semiconducting nanoparticles are transparent metal oxide. The semiconducting nanoparticles include tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or titanium dioxide (TiO.sub.2). In an embodiment, the POM is [SiW.sub.12O.sub.40].sup.4−; [α-P.sub.2W.sub.18O.sub.62].sup.6−; or [α.sub.2-P.sub.2W.sub.17O.sub.61].sup.10−. The semiconducting nanoparticles bond to the POM through a combination of electrostatic interactions and hydrogen bonds. The porous transparent electrode can be placed in a protonated form or ion-paired with alkali metal cations or tetraalkylammonium cations.

A porous transparent electrode is formed where a film comprising of semiconducting nanoparticles is decorated with polyoxometalates (POMs) bonded to their surfaces. The semiconducting nanoparticles are transparent metal oxide. The semiconducting nanoparticles include tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or titanium dioxide (TiO.sub.2). In an embodiment, the POM is [SiW.sub.12O.sub.40].sup.4−; [α-P.sub.2W.sub.18O.sub.62].sup.6−; or [α.sub.2-P.sub.2W.sub.17O.sub.61].sup.10−. The semiconducting nanoparticles bond to the POM through a combination of electrostatic interactions and hydrogen bonds. The porous transparent electrode can be placed in a protonated form or ion-paired with alkali metal cations or tetraalkylammonium cations.

The present invention relates to a system for superimposing alternating current on direct current flowing through one or more electrolytic cells, for electro-winning or electro-refining processes, in which the terminals of an alternating current source are connected to the first and last electrode of a cell or a group of cells.