Synthesis and Property of Platinum-cobalt Alloy Nano Catalyst

In order to achieve the commercialization of proton exchange membrane fuel cells (PEMPCs), it is necessary to synthesize electrocatalyst with higher electrochemical activity. In this study, PtCo nano-alloy electrocatalyst was prepared by liquid phase synthesis method with sodium borohydride as reducing agent, triethylamine as complexing agent, and by sequential heat-treatment. The physical properties of the catalyst were characterized by different analytical methods. We studied the effects of heat-treatment temperature, different amounts of sodium borohydride and triethylamine on electrochemical performance. The results show that heat-treatment can greatly improve the mass activity of the catalyst, and 500 degrees C is the optimal temperature for preparing the catalyst with the highest catalytic performance towards oxygen reduction reaction(ORR). Compared with commercial TKK-PtCo alloy catalyst under the same test system, the as-prepared catalysts exhibits advantages of more uniform particle size distribution, smaller particle size and higher electrochemical performance. In particular, the mass activity (MA) of the prepared catalyst is 133 mA/mg(pt), which is 3 times of TKK-PtCo alloy catalyst.