碱性氢氧化反应中非Pt贵金属电催化剂的研究进展

Advances in non-Pt precious metal electrocatalysts in alkaline hydrogen oxidation reaction

氢氧根交换膜燃料电池(HEMFCs)技术快速发展,碱性介质中用于催化阴极氧还原反应(ORR)的非贵金属电催化剂已有广泛研究。但HEMFCs存在的一个巨大挑战是阳极氢氧化反应(HOR)相对缓慢的动力学,因此需要较高负载量的Pt基阳极电催化剂才能实现较高的性能,这制约了HEMFCs的发展。由于Pt价格昂贵、地球储量有限,开发非Pt阳极HOR电催化剂被认为是减少Pt用量和降低燃料电池生产成本的可行途径。这里从电催化剂的异质结构、支撑效应、金属合金等方面,总结了近3年来非Pt贵金属(Ru、Rh、Pd、Ir)基HOR电催化剂的最新研究进展,归纳了相应的电催化性能,并阐明了其HOR机理。最新报道的非Pt HOR电催化剂可以降低阳极电催化剂的成本,并具有与商业Pt/C媲美的活性与稳定性。最后,基于目前对非Pt贵金属电催化剂结构特征分析,进一步对HOR研究的未来发展方向做出了展望。

Hydroxide exchange membrane fuel cells(HEMFCs)technology is rapidly developing and non-precious metal electrocatalysts for catalyzing cathodic oxygen reduction reaction(ORR)in alkaline media have been extensively investigated.However,a major challenge for HEMFCs is the relatively slow kinetics of the anodic hydrogen oxidation reaction(HOR),which limits the development of HEMFC,thus requiring high loadings of Pt-based anode electrocatalysts to achieve high performance.Due to the high price of Pt and limited earth reserves,the development of non-Pt anode HOR electrocatalysts is considered a viable way to reduce the amount of Pt usage and lower the cost of fuel cell production.Here,we reviewed the latest research progress of non-Pt precious metal(Ru,Rh,Pd,Ir)-based HOR electrocatalysts in the past three years in terms of their heterogeneous structure,support effects and metal alloys,summarized the corresponding electrocatalytic performance,and elucidated their HOR mechanisms.The recently reported non-Pt HOR electrocatalysts could reduce the cost of anode electrocatalysts and had activity and stability comparable to that of commercial Pt/C.Finally,based on the current structural characterization of non-Pt precious metal electrocatalysts,an outlook on the future development of HOR research was further provided.