用于质子交换膜燃料电池的高活性、高稳定性PdCo/C合金催化剂

Remarkably Active and Durable PdCo/C Alloy Catalysts for Proton Exchange Membrane Fuel Cells

利用乙酸钴和双氰胺在不同温度下制备了碳包覆钴样品,并将其作为载体,利用液相还原法和真空热处理制备了PdCo/C合金催化剂。采用多种测试技术对样品进行了结构、形貌及组分的表征,研究了不同载体和不同热处理温度的样品的催化性能。实验结果表明,平均粒径为1.9nm的钯纳米颗粒能够均匀负载到含氮的石墨化程度较低的碳包覆钴载体上。热处理带来的合金化作用能够极大地提高催化剂的氧还原活性和稳定性,经过900℃热处理的样品其氧还原活性和稳定性都优于传统商业Pt/C催化剂。

Carbon-coated cobalt samples were prepared at different temperatures using cobalt acetate and dicyandiamide.PdCo/C alloy catalysts were synthesized on the carbon-coated cobalt substrate by a liquid reduction and heat treatment method.All samples were characterized by several methods to study the morphologies and crystallization properties of the catalysts.Electrochemical measurements were used to test the catalytic performance of the samples with different supports and different heat treatment temperatures.Results show that Pd nanoparticles with an average particle diameter of 1.9 nm can be uniformly deposited on the nitrogen-containing carbon-coated cobalt support with a lower degree of graphitization.It is proved that great improvement of the activity and stability of the catalysts toward oxygen reduction reaction(ORR)can be achieved by the alloying effect,and the catalyst annealed at 900℃has better ORR activity and stability than the conventional commercial Pt/C catalyst.