Dissolution-redeposition dynamics as a universal restructuring mechanism of electrocatalysts.

Abstract

Electrocatalysts are often assumed to be structurally stable; yet in practice, they continuously dissolve and restructure, directly affecting the number and nature of active sites and therefore performance. Although dissolution-redeposition-driven evolution is well recognized in some electrocatalysis communities, others still interpret activity and selectivity as properties of static surfaces. We argue that across electrocatalytic technologies, especially under demanding industrially relevant timescales, "static" electrocatalysts are a myth: even parts-per-billion metal fluxes can cumulatively change surface structure, poison membranes, degrade supports, and thus shift device performance. Controlling these changes requires a mechanistic understanding of when dissolution, transport, and redeposition are promoted or suppressed by, for instance, potential, pH, reactants, or local microenvironments. Here, we unify evidence for restructuring across metal and metal-derived catalysts under various electrochemical reactions, highlight common driving forces, and summarize the appropriate tools to quantify it. Ultimately, electrocatalysts should be evaluated, designed, and interpreted as dynamically stable materials and not as static electrochemical interfaces.