Surface functional groups (FGs) play a central role in energy conversion and synthetic chemistry. Precise control over their properties and reactivities is essential for the rational design and optimization of both electrocatalytic and heterogeneous catalytic systems. Despite their importance, fundamental understanding of surface FGs—including their binding behavior, electronic structure, and interfacial reactivity and selectivity—remains limited. Our lab aims to bridge this knowledge gap by investigating these reactive surface intermediates through the integrated lenses of interfacial electrochemistry, physical organic chemistry, materials science, etc.