ELECTROCHEMICAL CELLS HAVING MIXED VALENCY TRANSITION METAL PEROVSKITES AS CATHODIC REDUCTION CATALYSTS

摘要

1363110 Fuel cell electrodes ESSO RESEARCH & ENG CO 4 Oct 1971 46054/71 Heading B1E [Also in Divisions Cl C7 and H1] The cathode of a fuel or other electrochemical cell having an alkaline electrolyte has a catalyst comprising a mixed valency non- noble metal perovskite of the general formula A x ASP1/SP y BO 3 where' A, ASP1/SP are metals of different valencies selected from Groups IA, IIA and IIIA and B is a non-noble transition metal selected from Groups IVA, VA, VIA, VIIA and VIII, and the sum of x and y is 1, the perovskite being a solid solution of a first oxide having the formula ABO 3 and a second oxide having the formula ASP1/SPBO 3 , the metal B having different valencies in the first and second oxides, the sums of the valencies of A and B and of ASP1/SP and B both being 6. Preferably, A is a lanthanide series metal, ASP1/SP is an alkaline earth metal and B is Ti, V, Cr, Mn, Fe, Co or Ni. Stoichiometric compositions of examples are: La 0À7 Ba 0À3 TiO 3 , La 0À7 Ba 0À3 MnO 3 , La 0À7 Ba 0À3 FeO 3 , La 0À7 Ba 0À3 CoO 3 . A cathode may be formed by mixing a desired perovskite with an aqueous emulsion containing P.T.F.E. applying the paste to a nickel or nickel alloy screen and subjecting the coated screen to heat and pressure. The cathode may also be used in electrolytic cells for the production of organic chemicals.