N掺杂多孔碳负载Co_(4)S_(3)的制备及其电化学氧还原反应催化性能研究

Preparation and oxygen reduction reaction occurring at the cathode catalytic performance of nitrogen-doped porous carbon loaded with Co_(4)S_(3)

近年来,高能量密度、清洁环保的燃料电池发展迅速,作为汽车动力电源、穿戴电源展现出重要的潜力。然而,由于燃料电池在放电时,阴极发生的氧还原反应(ORR)存在很高的过电位和缓慢的动力学过程,亟需高性能廉价的电催化剂以提高电池效率。本文以处理后的油菜花粉为前驱体,通过水热、硫化、退火工艺制备了一种N掺杂多孔碳负载Co_(4)S_(3)纳米颗粒复合材料(Co_(4)S_(3)/PC)。Co_(4)S_(3)/PC表现出优异的ORR催化性能:其催化起始电位为0.96 V,半波电位为0.80 V,极限电流为5.03 mA·cm^(-2),接近商业Pt/C催化剂的催化活性。同时Co_(4)S_(3)/PC还具备持久的催化稳定性:循环5000次后,催化ORR反应极限电流仍保持95.8%。这种源于生物质的复合材料为制备燃料电池阴极催化剂提供了一种低成本方案。

In recent years,the fuel batteries with high energy density and clean environmental protection have developed rapidly,showing important potential as automobile power source and wearable power source.However,due to the high overpotential and slow kinetic process of oxygen reduction reaction(ORR)occurring at the cathode during fuel batteries discharge,high-performance and cheap electrocatalysts are urgently needed to improve the efficiency of batteries.In this paper,an N-doped porous carbon loaded with Co_(4)S_(3) nanoparticles composite(Co_(4)S_(3)/PC)has been prepared by employing treated rape pollen as precursor during hydrothermal,sulfurization and annealing processes.The Co_(4)S_(3)/PC exhibited excellent electrocatalytic activity in ORR:the initial potential,the half-wave potential,and the limiting current were 0.96 V,0.80 V and 5.03 mA·cm^(-2),closing to the catalytic activity of commercial Pt/C catalyst.At the same time,the Co_(4)S_(3)/PC also exhibited a durable catalytic stability:after 5000 cycles,the limit current of catalytic ORR reaction remained 95.8%.The composite material derived from biomass provides a low-cost solution for the preparation of cathode catalyst for fuel batteries.