Heterointerface‑Enabled Electrocatalysis for Efficient Energy Conversion.

Electrochemical processes hold significant promise for renewable‑energy conversion and decreasing the reliance on fossil fuels. Progress in this field hinges on efficient and durable electrocatalysts, which has spurred immense research efforts in catalyst design and engineering. Heterointerface has been shown to be an effective strategy in enhancing the performance of electrocatalysts in important electrochemical reactions involving small molecules. This review summarizes how interfacial structures influence charge‑transfer dynamics, active‑site identity and its density, catalytic activity, and long‑term stability. Interface‑induced effects are first introduced, followed by a survey of common synthetic strategies for heterostructured electrocatalysts. The role of heterointerface in electrocatalysis is discussed using the representative electrochemical conversion of small molecules. We highlight recent progress across energy‑conversion reactions, focusing on interface‑enabled functionalities, and systematically evaluate strategies and performance across diverse electrocatalytic contexts. Finally, we discuss future challenges and opportunities-including innovations in synthesis, advanced characterization, and theory and computation-to guide rational interface design. Overall, this review provides actionable insights for heterostructured electrocatalysts in energy conversion and supports progress toward carbon neutrality.