Abstract
To fulfill the evergrowing energy consumption demands and the pursuit of sustainable and renewable energy, electrocatalytic reactions such as the water electrocatalysis reaction, the O(2) reduction reaction, the N(2) reduction reaction (NRR), the CO(2) reduction reaction (CO(2)RR), etc., have drawn a lot of attention. Scanning electrochemical microscopy (SECM) is a powerful technique for in situ surface characterization, providing critical information about the local reactivity of electrocatalysts and unveiling key information about the reaction mechanisms, which are essential for the rational design of novel electrocatalysts. There has been a growing trend of SECM-based studies in electrocatalytic reactions, with a major focus on water splitting and O(2) reduction reactions, and relying mostly on conventional SECM techniques. Recently, novel operation modes of SECM have emerged, adding new features to the functionality of SECM and successfully expanding the scope of SECM to other electrocatalytic reactions, i.e., the NRR, the NO(3) (-) reduction reaction (NO(3)RR), the CO(2)RR and so on, as well as more complicated electrolysis systems, i.e. gas diffusion electrodes. In this perspective, we summarized recent progress in the development of novel SECM techniques and recent SECM-based research studies on the NRR, NO(3)RR, CO(2)RR, and so on, where quantitative information on the reaction mechanism and catalyst reactivity was uncovered through SECM. The development of novel SECM techniques and the application of these techniques can provide new insights into the reaction mechanisms of diverse electrocatalytic reactions as well as the in situ characterization of electrocatalysts, facilitating the pursuit of sustainable and renewable energy.