电催化析氢反应中的氢溢流效应

Hydrogen Spillover Effect in Electrocatalytic Hydrogen Evolution Reaction

电解水制氢技术碳排放量低、能量利用率高、所得氢气纯度高,在多数制氢技术中具有显著优势,业已成为学术界和工业界的研究热点。其中,电催化析氢反应(HER)处于核心地位,常涉及多步氢转移过程和多个活性位点共同参与的情况。然而,这些活性位点之间的催化关联和潜在的氢溢流效应常被忽视。本文回顾了过渡金属氧化物、磷化物和硫化物等的电催化体系的析氢性能和反应机制;结合传统热催化理论,将参与氢溢流的活性位点抽象总结为初级和次级活性位点,并明晰了它们的催化关联和功能差异;本文将不仅为高效廉价析氢电催化剂的创制提供一种设计理念,也为进一步研究涉氢电催化反应中的氢转移行为提供参考。

Water electrolysis for hydrogen harvesting has become a research hotspot in both academia and industry due to its low carbon emissions,high energy efficiency,and high purity,which offer significant advantages over the majority of hydrogen production technologies.Thereinto,the electrocatalytic hydrogen reaction(HER)is at the core,which aways involves a multi-step hydrogen transfer process and multiple active sites working together.However,catalytic correlations between those active sites and potential hydrogen spillover effects involved are often overlooked.In this paper,we first review the hydrogen evolving properties and reaction mechanisms in electrocatalytic systems such as transition metal oxides,phosphides,and sulfides.By combining traditional theories of thermal catalysis,active sites involved in hydrogen spillover are then conceptually summarized into both the primary and secondary active sites,elucidating their catalytic relevance and functional differences.This paper will not only provide a design concept for the creation of efficient and inexpensive electrocatalysts for hydrogen evolution,but also serve as a useful reference for further studies of hydrogen transfer behaviors in other hydrogen-involved electrocatalytic reactions.