金属间化合物Pt_(7)Sb投影Berry相位与析氢催化关联的第一性原理计算

First-Principles Study of Projected Berry Phase and Hydrogen Evolution Catalysis in Pt_(7)Sb

高效催化材料的设计是能源材料领域的重要任务之一。本工作根据寻找具有低Pt负载量的高效析氢反应(HER)催化剂的指导原则,结合投影Berry相位描述符,设计发现了性能优异的HER催化剂立方Pt_(7)Sb,其氢吸附Gibbs自由能(ΔG_(H^(*)))甚至小于Pt元素。因此,在降低Pt负载量的情况下,其HER催化活性有望提高。从电子结构分析来看,2个描述符ΔG_(H^(*))和投影Berry相位之间有很好的一致性。由于投影Berry相位完全由体态(波函数相位)决定,这种一致性意味着良好的催化性能与本征电子结构的拓扑性质之间存在着密切的关系。该结果提供了一个很好的HER催化剂候选材料,降低了Pt的负载量,并为展示催化剂本征拓扑性质的作用提供了参考。

With the increase of global energy consumption and related environment pollution,new types of renewable clean energy resources and carriers are desirable.Given its high gravimetric energy density and combustion product(i.e.,water),molecular hydrogen has attracted considerable attention.Obtaining molecular hydrogen from water splitting is the ideal strategy because inputs and outputs are carbon-free clean matter.In achieving this process,a suitable and highly efficient catalyst is a crucial parameter.Novel metal Pt is an excellent catalyst with high efficiency and chemical stability.However,owing to its high cost and insufficient reserves on Earth,the wide application of Pt in catalysis is strongly limited.Correspondingly,the design of a highly efficient hydrogen evolution reaction(HER)catalyst with low Pt loading is an important task for electrochemical water splitting in the field of renewable energy resources.Understanding the hidden mechanism is essential for the guiding principle of such a design.In this study,an excellent HER catalyst in cubic Pt_(7)Sb is proposed,in which Gibbs free energy for hydrogen adsorption(ΔG_(H^(*)))is smaller than that from Pt.Thus,together with its good chemical stability,a better HER catalytic activity with reduced Pt loading can be obtained.Based on the analysis of electronic structures,a good agreement between the two descriptors of ΔG_(H^(*))and the projected Berry phase(PBP)is revealed.Considering that the PBP is purely decided by the bulk state,such an agreement indicates a strong relationship between the good catalytic performance and the topological nature of the intrinsic electronic structure.This work provides an excellent HER catalytic candidate with reduced Pt loading and a good example to show the role of the intrinsic topological nature in catalysts.