Modifying Pt surfaces by foreign metals with a higher oxophilicity is a promising approach to improve the kinetics of hydrogen evolution and oxidation reactions. The role of foreign metals, however, is not fully understood. Here we study Ru-modified Pt as a model system to understand the underlying mechanisms in activity improvement through combining in situ infrared spectroscopy and theoretical calculations. In an alkaline solution, the hydrogen evolution and oxidation reaction activity of Ru-modified Pt is proportional to the Ru coverage due to the strain and electronic effects of the Pt substrate, which lower the energy barrier of the rate-determining Volmer step; these are the governing reasons for the improved catalytic activities. This work not only deepens our understanding of hydrogen electrocatalysis mechanisms, but also provides guidelines for the rational design of advanced electrocatalysts.

用具有更高亲氧性的外来金属修饰 Pt 表面是改善析氢和氧化反应动力学的有前途的方法。然而，外来金属的作用尚不完全清楚。在这里，我们研究了 Ru 修饰的 Pt 作为模型系统，通过结合原位红外光谱和理论计算来了解活性提高的潜在机制。在碱性溶液中，由于Pt衬底的应变和电子效应，Ru修饰Pt的析氢和氧化反应活性与Ru覆盖率成正比，降低了决定速率的Volmer步的能垒；这些是提高催化活性的主要原因。这项工作不仅加深了我们对氢电催化机理的理解，