基于结构调控的Pt基氧还原催化剂的研究进展

Research Progress on Pt-Based Catalysts Based on Structural Regulation for Oxygen Reduction Reaction

贵金属Pt基催化剂作为氧还原反应(ORR)中重要的催化剂之一,因储量有限且价格昂贵,限制了其规模化应用。如何提高Pt的利用率是目前开发高性能氧还原催化剂的关键。特别是,对催化剂进行结构调控(形貌、晶相、晶面、电子结构),可以有效提升Pt原子利用率及其本征活性,但由于表面效应和小尺寸效应使Pt纳米粒子具有较高的表面能和化学活性,导致它在化学反应中不稳定,影响催化剂的寿命。因此,开发具有高本征活性、高暴露活性晶面且结构稳定的Pt基催化剂依然是质子交换膜燃料电池领域的一个重大挑战。针对近年来该领域催化剂的研究进展进行综述。重点讨论通过调控Pt基纳米催化剂的形貌、晶相、晶面和电子结构等结构要素,提高Pt基纳米催化剂氧还原性能的设计理念与制备技术。最后简要总结Pt基纳米催化剂面临的挑战和研究重点。

Precious-metal Pt-based catalysts,as one of the important catalysts in oxygen reduction reaction(ORR),have the limited reserves and high prices,limiting their large-scale application.How to improve the utilization rate of Pt is currently the key to develop high-performance catalysts for ORR.Especially,structure regulation(morphology,crystal phases,exposed crystal planes,electronic structure)of catalysts can effectively improve the utilization efficiency and intrinsic activity of Pt atoms.However,Pt nanoparticles have high surface energy due to their surface effect and small size effect,which leads to their instability in chemical reactions and affects the lifespan of the catalyst.Therefore,it remains still a major challenge to obtain Pt nanoparticles with high intrinsic activity,high exposure activity,and stable structure for Pt-based catalysts in the field of proton exchange membrane fuel cell(PEMFC).This article provides a review of the research progress in this field in recent years.The focus is on discussing the design concept and preparation technology of improving the oxygen reduction performance of Pt based nanocatalysts by regulating their structural elements such as morphology,crystal phase,crystal plane,and electronic structure.Finally,a brief summary is given for the challenges and research priorities faced by Pt-based catalysts for ORR.