Advanced in situ characterization techniques for studying the dynamics of solid-liquid interface in electrocatalytic reactions

The reaction kinetics at the solid-liquid interface significantly affects the rate of electrocatalytic reactions. At the atomic and molecular levels, accurately identifying the structural evolution of active sites, the evolution of reaction intermediates, and the mechanism of catalytic reactions play an important role for designing efficient catalysts in electrochemical energy storage and conversion technologies, though it remains highly challenging. This review systematically scrutinizes recent achievements in the dynamic investigation of solid-liquid electrochemical interfaces during electrocatalysis, using in situ synchrotron X-ray absorption fine structure (SR-XAFS) and synchrotron Fourier-transform infrared spectroscopy (SR-FTIR). It provides a comprehensive discussion on the continuous development of in situ SR-XAFS and SR-FTIR, with particular emphasis on the content of multi-scale monitoring the structural evolution of active centers. Moreover, the review highlights the unique and powerful role of correlative SR-XAFS/FTIR in exploring the dynamic of solid-liquid electrochemical interfaces in mainstream research areas such as electrocatalytic water splitting, oxygen reduction, nitrate reduction, and carbon dioxide reduction. Finally, the challenges and prospects of identifying the kinetic behavior of solid-liquid electrocatalytic interfaces in electrocatalytic materials under working conditions. This review aims to offer ample, reliable, and complementary information on the dynamic evolution of the interface during the electrocatalytic process, thereby guiding the rational design of advanced catalytic materials with outstanding activity, selectivity, and stability.