Preparation of C/PTFE gas diffusion electrode and its application in electro-synthesis of hydrogen peroxide

C/PTFE gas diffusion electrode was prepared, and hydrogen peroxide electro-synthesis by oxygen reduction was investigated with it in membrane reactor. The influences of H⁺ concentration and Na₂SO₄ concentration on oxygen-reduction for H₂O₂ generation were studied by cyclic voltammogram and constant current electrolysis. Mechanism transformation was found, resulting from the sharp increase of pH, which was favorable for H₂O₂ generation. On the contrary, H₂O₂ accumulation was not propitious for its synthesis. High current efficiency (>80%), high H₂O₂ concentration (>0.3%) and stable pH were also achieved simultaneously by open constant electrolysis. Deep oxidation loss of H₂O₂ in anode was effectively reduced by membrane.