Electrocatalyst, electrode coating and electrode for the production of chlorine

Electrocatalyst for preparation of chlorine by electrolysis of chlorine ion containing electrolytes comprising at least one precious metal oxide and/or noble metal of subgroup VIIIa of the periodic table of the elements (in particular selected from the group of Ru, Rh, Pd, Os, Ir, Pt ), finely powdered oxide of another metal (non-noble metal oxide powder), where the non-noble metal oxide powder is chemically stable in the presence of aqueous electrolytes, is new. Independent claims are included for: (1) an electrocatalytic coating comprising the electrocatalyst; (2) an electrode for producing chlorine by electrolysis of chlorine-ion-containing aqueous electrolytes of at least one electrically conductive carrier and a catalytically active coating, where the catalytically active coating comprises the electrocatalyst; and (3) producing the electrodes, comprising applying a layer of at least one finely divided non-noble metal oxide powder, preferably titanium oxide, at least one noble metal and/or noble metal of sub-group of VIIIa of the periodic table of the elements, and optionally the valve metal or a valve metal oxide and a doped non-noble metal oxide powder onto an electrically conductive support consisting of a valve metal including titanium (preferred), zirconium, tungsten, tantalum or niobium, in which a mixture of non-noble metal oxide powder, a solvent, a noble metal compound soluble in the solvent, and a soluble non-noble metal compound and optionally a valve metal compound and/or optionally the soluble dosing element compound is applied on the electrically conductive support, is dried to remove solvent, and then is sintered at elevated temperature.