Toward Rational Electrocatalyst Design: Dynamic Insights from Liquid Environmental Transmission Electron Microscopy.

Abstract

Electrocatalysis, a pivotal field at the intersection of physical chemistry and materials science, plays a crucial role in advancing energy conversion and storage technologies through rational catalyst design. However, understanding reaction mechanisms at the atomic level remains a great challenge due to the intricate interplay between catalysts, reactants, and complex environments (e.g., electric fields, liquid electrolytes). This complexity has led to persistent "material" and "environment" gaps between conventional electrocatalytic research and the practical behavior of catalysts under realistic operating conditions. The emergence of liquid environmental transmission electron microscopy (LETEM) enables the characterization of the electrocatalysts coupled with precise electrochemical measurements under operando conditions with both high spatial and temporal resolutions. Recent breakthroughs in atomic-scale characterization of dynamic processes of electrocatalysts under realistic reaction environments have demonstrated the exceptional potential of LETEM for elucidating the nature of electrocatalysis and establishing robust atomic-level structure-activity relationships. This review offers a comprehensive overview of the research progress in the dynamic evolution of electrocatalysts via LETEM, with a particular focus on the structural evolution of electrocatalysts under electro-liquid coupled environments. This review is expected to provide insights for unlocking fundamental mechanisms and the rational design of high-performance electrocatalysts.