Abstract
In the recent years, the transition of dynamic electronic structure has been demonstrated to be induced by some external stimulus during catalysis, which enable one to potentially manipulate the unpaired electrons at the metal centers, thus directly influencing their dynamic structure as well as resulting nature. In this respect, the recent research trends have increasingly transferred from optimizing catalysts to making clear the real active species of the catalysts, especially understanding the underlying mechanisms behind these catalytic reactions. Regarding the advanced in situ/operando approaches, ongoing characterization efforts employing X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) have successfully unveiled the potential-induced or photo-driven changes in local geometry of the active sites. It is believed that the perspective raised in the present work will provide a new avenue to the design of highly active electrocatalysts at the atomic scale.