Electrochemical promotion of catalytic reactions with Pt/C (or Pt/Ru/C)//PBI catalysts

Abstract

The paper is an overview of the results of the investigation on electrochemical promotion of three catalytic reactions: methane oxidation with oxygen, NO reduction with hydrogen at 135 °C and Fischer–Tropsch synthesis (FTS) at 170 °C in the [CH4/O2(or NO/H2 or CO/H2)/Ar//Pt (or Pt/Ru)//PBI(H3PO4)/H2, Ar] fuel cell. It has been shown that the partial methane oxidation to C2H2 and the C2 selectivity were electrochemically promoted by the negative catalyst polarization. This was also the case in NO reduction with hydrogen for low NO and H2 partial pressures. In both cases the catalytic reactions have been promoted by the electrochemically produced hydrogen. It has been found that the NO reduction with hydrogen on the Pt/PBI strongly depends on NO and hydrogen partial pressures in the working gas mixture. At higher NO and H2 partial pressures the catalysis is promoted by the electrochemical pumping of H+ from the catalyst, i.e. at positive polarization. FTS demonstrated the highest methane production rate (11% of CO conversion) at zero fuel cell voltage.