Abstract: An electrode suitable for chlorine evolution in electrolysis cells consists of a metal substrate coated with two distinct compositions applied in alternate layers, the former comprising oxides of iridium, ruthenium and valve metals, for instance tantalum, and the latter comprising oxides of iridium, ruthenium and tin. The thus-obtained electrode couples excellent characteristics of anodic potential and selectivity towards the chlorine evolution reaction.

Abstract: An electrode for electrochemical generation of hypochlorite is provided. The electrode has a valve metal substrate coated with a catalytic system consisting of two superimposed layers of distinct composition and having a different activity towards hypochlorite anodic generation from chloride solutions. The electrode has a high duration in cathodic operation conditions, imparting self-cleaning characteristics thereto when used in combination with an equivalent one with periodic polarity reversal. Moreover, the deactivation of the electrode at the end of its life cycle occurs in two subsequent steps, allowing to schedule the substitution thereof with a significant notice period.

Abstract: The invention relates to a cathode for electrolytic processes provided with a catalytic coating based on ruthenium crystallites with highly controlled size falling in a range of 1-10 nm. The coating can be produced by physical vapor deposition of a ruthenium or ruthenium oxide layer.

Abstract: The invention relates to an electrode suitable as anode for evolution of gaseous products comprising a metal substrate coated with at least one titanium suboxide layer having an interconnected porosity and containing catalytic noble metal oxides. The invention further relates to a method of manufacturing such electrode comprising applying a mixture of titanium suboxides and noble metal oxide-based catalyst on a valve metal substrate via cold gas spray technique.

Abstract: The invention relates to an electrode for evolution of gaseous products in electrolysis cells comprising e metal substrate coated with at least two catalytic compositions, the outermost catalytic composition being deposited by means of chemical or physical phase vapour deposition technique and having a composition comprising noble metals selected from the group of platinum group metals or oxides thereof.

Abstract: An electrode suitable for chlorine evolution in electrolysis cells consists of a metal substrate coated with two distinct compositions applied in alternate layers, the former comprising oxides of iridium, ruthenium and valve metals, for instance tantalum, and the latter comprising oxides of iridium, ruthenium and tin. The thus-obtained electrode couples excellent characteristics of anodic potential and selectivity towards the chlorine evolution reaction.

Abstract: The invention relates to an electrode for electrochemical generation of hypochlorite. The electrode comprises a valve metal substrate coated with a catalytic system consisting of two super-imposed layers of distinct composition and having a different activity towards hypochlorite anodic generation from chloride solutions. The electrode has a high duration in cathodic operation conditions, imparting self-cleaning characteristics thereto when used in combination with an equivalent one with periodic polarity reversal. Moreover, the deactivation of the electrode at the end of its life cycle occurs in two subsequent steps, allowing to schedule the substitution thereof with a significant notice period.

Abstract: The invention relates to an electrode formulation comprising a catalytic layer containing tin, ruthenium, iridium, palladium and niobium oxides applied to a titanium or other valve metal substrate. A protective layer based on titanium oxide modified with oxides of other elements such as tantalum, niobium or bismuth may be interposed between the substrate and the catalytic layer. The thus obtained electrode is suitable for use as an anode in electrolysis cells for chlorine production.

Abstract: The invention relates to a cathode for electrolytic processes provided with a catalytic coating based on ruthenium crystallites with highly controlled size falling in a range of 1-10 nm. The coating can be produced by physical vapour deposition of a ruthenium or ruthenium oxide layer.

Abstract: The invention relates to a method of manufacturing of metal electrodes for electrolytic applications by means of a continuous deposition of a layer of noble metals upon metal substrates by a physical vapour deposition technique.

Abstract: The invention relates to an electrode formulation comprising a catalytic layer containing tin, ruthenium, iridium, palladium and niobium oxides applied to a titanium or other valve metal substrate. A protective layer based on titanium oxide modified with oxides of other elements such as tantalum, niobium or bismuth may be interposed between the substrate and the catalytic layer. The thus obtained electrode is suitable for use as an anode in electrolysis cells for chlorine production.

Abstract: The invention relates to a gas-diffusion electrode for chlor-alkali electrolysis cells integrated in a percolator of plastic porous material suitable for being vertically crossed by a downward flow of electrolyte. The electrode comprises a catalytic composition based on silver and/or nickel mixed to a polymeric binder, directly supported on the percolator without any interposed reticulated metal current collector.

Abstract: The invention relates to a cathode for electrolytic processes, particularly suitable for hydrogen evolution in chlor-alkali electrolysis, consisting of a nickel substrate provided with a coating comprising a protective zone containing palladium and a physically distinct catalytic activation containing platinum or ruthenium optionally mixed with a highly oxidizing metal oxide, preferably chromium or praseodymium oxide.

Abstract: The invention relates to a cathode for electrolytic processes, particularly suitable for hydrogen evolution in chlor-alkali electrolysis, consisting of a nickel substrate provided with a coating comprising a protective zone containing palladium and a physically distinct catalytic activation containing platinum or ruthenium optionally mixed with a highly oxidising metal oxide, preferably chromium or praseodymium oxide.

Abstract: The invention relates to a gas-diffusion electrode for chlor-alkali electrolysis cells integrated in a percolator of plastic porous material suitable for being vertically crossed by a downward flow of electrolyte. The electrode comprises a catalytic composition based on silver and/or nickel mixed to a polymeric binder, directly supported on the percolator without any interposed reticulated metal current collector.

Abstract: Process for the reduction of a hexavalent chromium oxide based catalyst comprising contacting, under mixing conditions, a hexavalent chromium oxide based catalyst, with a molar excess, in respect of the chromium species, of a solid reducing agent and subjecting the mixture to a temperature in the range 30-1000° C. The process is simple, involves low costs and allows to obtain a permanently reduced chromium catalyst that can be disposed without toxicity risks.

Abstract: Process for the reduction of a hexavalent chromium oxide based catalyst comprising contacting, under mixing conditions, a hexavalent chromium oxide based catalyst, with a molar excess, in respect of the chromium species, of a solid reducing agent and subjecting the mixture to a temperature in the range 30-1000 C.°. The process is simple, involves low costs and allows to obtain a permanently reduced chromium catalyst that can be disposed without toxicity risks.