The transition metal complex of cobalt tetrasulfonate phthalocyanine (CoTSPc) was added into the electrolyte of 0.5 mol•L^－1 sulfuric acid and its effect on oxygen reduction and methanol tolerant ability at cathodic Pt electrode was studied. The results showed that this kind of effect was concentration dependent and when the concentration of CoTSPc in the electrolyte was 0.09 mmol•L^－1, the oxygen reduction reaction at the cathodic Pt electrode was not affected, however methanol oxidation at the same electrode was effectively restrained—methanol oxidation current was decreased by 79.7% compared to the case without CoTSPc in the electrolyte.

Key words: direct methanol fuel cell, cathodic oxygen reduction, cobalt tetrasulfonate phthalocyanine, methanol-tolerant