原子数精确的金属纳米团簇在电催化领域的应用研究进展

Application of Atomically Precise Metal Nanoclusters in Electrocatalysis

金属纳米团簇(MNCs)是由几个到数百个金属原子组成,其尺寸一般小于2nm。金属纳米团簇在许多催化反应中表现出高的催化活性和选择性,这与金属纳米团簇具有高的比表面积、较多暴露的活性原子,以及与金属纳米粒子(MNPs)不同的电子结构有关。金属纳米团簇确定的组成和结构使其成为一种新型模型催化剂,对纳米团簇的催化性能研究有利于人们深入理解催化剂结构-性质之间的关系,更利于催化剂的理性设计与发展。结合近几年国内外和本课题组在金属纳米团簇电催化领域的研究进展和现状,本文对该领域的代表性工作进行了简要综述,并对其未来在电催化领域的应用前景和需要解决的关键问题进行了展望。

Metal nanoclusters(M NCs)consist of only several to a few hundred of metal atoms and possess core sizes less than2 nm.Owing to the quantum size effect,the electronic states of M NCs evolve to discrete levels similar to the molecule energy gaps,other than a continuous density of states to produce plasmon characteristic of bulk metal nanoparticles(M NPs).In comparison with the conventional M NPs,M NCs exhibit dramatically unique electronic and optical properties,such as molecule-like energy gaps,strong photoluminescence and high catalytic properties,which make them promising for potential application in numerous fields,such as catalysis,chemical sensors,electronics,biological labeling and biomedicine.As a new type of highly efficient catalysts,MNCs have shown high catalytic activity and unique selectivity in many catalytic reactions,which are related to their ultrasmall size with relatively high surface area-to-volume ratio,high density of exposed active atoms,and the unique electronic structure different from that of bulk M NPs.For example,the M NCs showed good performances in many catalytic reactions,such as CO oxidation,propylene epoxidation,electrocatalytic water oxidation,propane dehydrogenation,acetylene cyclotrimerization and hydrogenation and polymerization reactions.M NCs can be used as model catalysts for theoretical simulation of the reaction pathway due to the precise compositions,atomically precise and tunable structures,which is helpful to study the intrinsic relationship between structure and property of nanostructure,and to rational design and fabricate advanced catalysts.In this review article,based on the present status of this field,we highlight the development of metal nanoclusters in recent years with focusing mainly on their application in electrocatalysis,including for fuel cell anode and cathode reactions,water splitting reaction and CO_(2) reduction.Finally,we give a brief outlook on the application of metal nanoclusters in electrocatalysis and the possible challenges.