The invention is a cathode arrangement comprising a cathode housing (20) defining a space (16) for cathode material and comprising a cathode housing wall being permeable to an electrolyte, and a collector member made of carbon, having a first end part extending into the space (16) for cathode material and a second end part extending outside the space (16) for cathode material, and cathode particles (10), having a cylindric shape with a diameter of 2-5 mm and being extruded from carbon, are arranged in the space (16) for cathode material. The invention is, furthermore, an energy cell comprising the cathode arrangement, an arrangement for processing hydrogen gas comprising the cathode arrangement and use the energy cell applying seawater or salt water as an electrolyte. Furthermore, the invention is a method for manufacturing the cathode arrangement.

Compositions comprising hydrogenated and dehydrogenated graphite comprising a plurality of flakes. At least one flake in ten has a size in excess of ten square micrometers. For example, the flakes can have an average thickness of 10 atomic layers or less.

Compositions comprising hydrogenated and dehydrogenated graphite comprising a plurality of flakes. At least one flake in ten has a size in excess of ten square micrometers. For example, the flakes can have an average thickness of 10 atomic layers or less.

This invention is directed to a method of oxygenating hydrocarbons with molecular oxygen, O.sub.2, as oxidant under electrochemical reducing conditions, using polyoxometalate compounds containing copper such as Q.sub.10[Cu.sub.4(H.sub.2O).sub.2(B-α-PW.sub.9O.sub.34).sub.2] or Q.sub.13{[Cu(H.sub.2O)].sub.3[(A-α-PW.sub.9O.sub.34).sub.2(NO.sub.3).sup.−]} or solvates thereof as catalysts, wherein Q are each independently selected from alkali metal cations, alkaline earth metal cations, transition metal cations, NH.sub.4.sup.+, H.sup.+ or any combination thereof.

A process and related electrode composition are disclosed for the electrocatalytic hydrogenation and/or hydrodeoxygenation of biomass-derived bio-oil components by the production of hydrogen atoms on a catalyst surface followed by the reaction of the hydrogen atoms with the organic compounds in bio-oil. The catalyst is a metal supported on a monolithic high surface area material such as activated carbon cloth. Electrocatalytic hydrogenation and/or hydrodeoxygenation stabilizes the bio-oil under mild conditions to reduce coke formation and catalyst deactivation. The process converts oxygen-containing functionalities and unsaturated bonds into chemically reduced forms with an increased hydrogen content. The process is operated at mild conditions, which enables it to be a good means for stabilizing bio-oil to a form that can be stored and transported using metal containers and pipes.

A process and related electrode composition are disclosed for the electrocatalytic hydrogenation and/or hydrodeoxygenation of biomass-derived bio-oil components by the production of hydrogen atoms on a catalyst surface followed by the reaction of the hydrogen atoms with the organic compounds in bio-oil. The catalyst is a metal supported on a monolithic high surface area material such as activated carbon cloth. Electrocatalytic hydrogenation and/or hydrodeoxygenation stabilizes the bio-oil under mild conditions to reduce coke formation and catalyst deactivation. The process converts oxygen-containing functionalities and unsaturated bonds into chemically reduced forms with an increased hydrogen content. The process is operated at mild conditions, which enables it to be a good means for stabilizing bio-oil to a form that can be stored and transported using metal containers and pipes.

Copper-boron-ferrite (Cu—B—Fe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

Copper-boron-ferrite (Cu—B—Fe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

In a first implementation, a method for exfoliation of graphene flakes from a graphite sample includes compressing a graphite sample in an electrochemical reactor and applying a voltage between the graphite sample and an electrode in the electrochemical cell.

In various aspects and embodiments the invention provides a method for preparing a metal periodate by anodic oxidation of a metal iodide in an electrolysis cell comprising one or more anodes and one or more cathodes, characterised in that the one or more anodes are carbon-comprising electrodes. In certain embodiments the method is characterised in that the one or more anodes comprise a diamond layer doped with one or more IUPAC group 13, 15 or 16 elements of the periodic table.