Effects of preparation on electrochemical properties of CoTMPP/G as catalyst for oxygen reduction reaction in acid media

摘要

Carbon supported Co tetramethoxy-phenylporphyrin (CoTMPP/C) catalysts have been synthesized by ultrasonic-assisted solvothermal method followed by heat-treatment in Ar atmosphere. The effects of preparation, including the solvent used for solvothermal reaction and the heat-treatment temperature, on electrochemical performance of the obtained CoTMPP/C catalysts towards oxygen reduction reaction (ORR) have been comparatively investigated. The results showed that the ORR peak potential could be improved by heat-treatment, it increases with increase in the calcination temperature, and then decreases when the heat-treatment temperature is larger than the optimal value, 600 ℃, where the best catalytic activity could be achieved. Among the used solvents of glacial acetic acid (HAc), methylene chloride (CH_2C1_2) and aqueous ammonia (NH_3H_2O), the catalysts prepared with HAc and NH_3H_2O demonstrated very close ORR peak potential and transferred-electron number, which are higher than that exhibited by the catalyst synthesized with CH_2C1_2. However, considering from points of ORR peak potential, transferred-electron number, synthesis convenience and environmental adaption, we suggest that glacial acetic acid is the optimal solvent to prepare high performance CoTMPP/ C catalyst for ORR.