Pd基氧还原反应纳米合金电催化剂研究进展

Research advances on Pd-based nanoalloy electrocatalysts for oxygen reduction reaction

在电催化过程中,反应物、中间态和最终产物分子与电催化剂表面的相互作用至关重要,因此对电催化剂表面的活性位点进行调控与修饰是电催化研究中极其重要的一部分,直接决定了电催化过程的效率和成本.首先,简单介绍了电催化的相关基础知识,以燃料电池阴极氧还原反应(oxygen reduction reaction,ORR)为例,介绍了反应过程机理和高效电催化剂的设计原则.然后,综述了电催化剂活性位点调控的最新进展及面临的挑战,主要包括Pd基纳米合金催化剂的结构和组成;介绍了如何利用各种物理效应(例如晶格应变和电子耦合效应)提升催化活性和稳定性.最后,围绕Pd基纳米合金催化剂性能的进一步提升以及贵金属电催化剂成本控制这两个问题,对其未来的合成策略和发展进行了展望.

In electrocatalysis processes,the interactions among reactants,reaction inter-mediates and their products,and the surfaces of electrocatalysts are of great significance.Therefore,the tailoring of active sites has become a primary focus in thefield of electro-catalysis,which directly determines the catalytic performance and cost of electro catalysis processes.Herein,the fundamentals of electrocatalysis were briefly introduced.The reac-tion mechanism and principles for designing high-efficiency electrocatalysts were presented using the anodic oxygen reduction reaction(ORR)of fuel cells as a typical model reaction.Recent advances and challenges in tailoring the active sites of ORR electrocatalysts were reviewed,including the structure and chemical composition,as well as the physical effects(eg.lattice-strain and electronic coupling effects)in boosting the catalytic activity and durability of Pd-based nanoalloy electrocatalysts.Finally,considering the cost of noble metal electrocatalysts and the improvements in catalytic performance in ORR processes,the perspectives on future synthetic strategies and developments of Pd-based nanoalloy electrocatalysts were presented.