One step synthesis of hydrogen peroxide through fuel cell reaction

The fuel cell system [O2, HCl aq. or H2SO4 aq., M(cathode)/Nafion—H/Pt(anode), H2] where M is Pt, Pd, Au, graphite or Au-mesh, cogenerates H2O2 and electricity. Current efficiency for the formation of H2O2 was 100% at the early stage of the reaction. However, the efficiency dropped sharply as H2O2 accumulated in the solution at cathode because of further electrochemical reduction and/or thermal decomposition of the H2O2. The rate of formation of H2O2 was controlled by mass transfer of oxygen. Thus, less active material such as graphite or Au-mesh was a better electrode for the synthesis of H2O2. The best conditions for the accumulation of H2O2 were as follows: M = Au-mesh, pH = 1.1 using HCl aq., pressure of hydrogen = 5 kPa, and pressure of oxygen ⩾ 101 kPa.