Electrochemical performance of dual catalysts system based on nickel phthalocyanine and nano-manganese dioxide for O_2 reduction

摘要

The electrochemical performance of the dual-catalyst system composed of nickel phthalocyanine (NiPc) and nano-manganese dioxide (nano-MnO_2) for O_2 reduction in alkaline media was studied. The electrocatalytic activities for oxygen reduction were evaluated by cyclic voltammeter method and linear sweep voltammeter method. The optimum ratio of NiPc and nano-MnO _2 was established by Job's method. The methanol tolerance property of dual catalysts with the optimum ratio was tested. The results implied that the dual catalysts showed excellent ORR activity involving a four-electron mechanism, with a Tafel slope of about 130 mV, indicating a one-electron process in the rate-determining step.