The Role of Surface Science in Electrocatalysis

Abstract Surface science has long provided the foundation for mechanistic understanding in electrocatalysis. In this perspective, we revisit its relevance through the lens of *H/*OH adsorption in the HUPD region of Pt and its role in CO electrooxidation, examples that illustrate principles that reach far beyond these systems. Electrochemical interfaces are complex and dynamic arenas where adsorbates, surface structure, and local electrolyte composition govern electrocatalytic performance. Untangling this complexity requires the atomic resolution of surface science, coupled with the reach of computational models. However, true predictive power comes only when theory and experiment act as partners, not substitutes. Rigorous mechanistic studies, often undervalued compared to the excitement of emerging materials, remain essential for achieving truly rational catalyst and electrolyte design.