燃料电池的阴极反应的反应动力学速率非常慢,限制了燃料电池技术的发展.因此,寻找低成本、高活性的氧还原催化剂具有重要的意义.多元金属核壳团簇表现出优良的氧还原活性.在本文中,以原子个数为19、38、55和79的八面体团簇作催化剂模型,采用密度泛函理论(GGA-PBE-PAW)方法,研究了一系列不同尺寸核壳Nim@Mn-m=19,38,55,79;m=1,6,13,19;M=Pt,Pd,Cu,Au,Ag)团簇催化剂的活性规律.优化*O、*OH和*OOH吸附中间体结构,计算了吸附自由能和反应吉布斯自由能,以超电势为催化活性的描述符,研究了单原子Pt嵌入Nim@Aun-m团簇的活性规律.结果 表明,Ni6@Pt1Au31具有最好的ORR活性,并且Ni1@Pt1Au17 、Ni6@Pt1Au31、Ni13@Pt1Au41、Ni1g@Pt1Au5表现出比Pt38团簇以及Pt(111)表面更高的催化活性.Bader电荷和态密度分析表面,核壳之间的电荷转移以及单原子Pt嵌入Nim@Aun-m表面,改变了吸附位的电子性质,降低了*OH的吸附强度,提高了ORR活性.单原子Pt嵌入Nim@Aun-m表面可能是一种合适的多元金属核壳ORR催化剂设计策略.“,”The slow kinetics of oxygen reduction reaction (ORR) limits the performance of low temperature fuel cells.Thus,it needs to design effective catalysts with low cost.Core-shell clusters (CSNCs) show promising activity because of their size-depen-dent geometric and electronic effects.The ORR activity trend of Nim@Pt1Aun-m-1(n =19,38,55,79;m =1,6,13,19) was studied using the GGA-PBE-PAW methods.The adsorption configurations of *O,*OH and *OOH were optimized and the reaction free energies of four proton electron (H+ + e-) transfer steps were calculated.Using overpotential as a descriptor for the catalytic activity,Ni6@Pt1Au31 was found to be the most active ORR catalyst.Ni1@Pt1Au17,Ni13@Pt1Au41,and Ni19@Pt1Au59 had better activity than pure Pt clusters and Pt(111).Bader charge and DOS data indicate that the single Pt atom embedded on Nim@Aun-m can tune the electronic property of active site,and thus,significantly improve the activity.The present study showed that the single Pt atom embedded on Nim@Aun-m is a rational strategy to design effective core-shell ORR catalysts.