Overcoming the Limitations of Operando Microscopy and Spectroscopy for Revealing Degradation Mechanisms of Electrocatalysts in Liquid Media: Correlative Approaches.

Operando microscopy methods applied in electrocatalysis come with critical limitations such as statistical relevance, interfering probe-sample interactions, and mass-transport-related phenomena on the one hand. On the other hand, those methods provide unique insights into dynamic processes that nanomaterials undergo during operation, insights that are inaccessible otherwise. Overcoming these challenges is, therefore, essential to disentangle, for instance, degradation mechanisms of electrocatalysts, knowledge that is urgently needed to drive forward our energy transition in a reasonable manner. This Mini-Review names the details of these challenges, provides recently published solutions, and depicts how operando microscopies can be embedded into correlative workflows to unfold their full potential. This way, insights gained from investigating model systems employing electrochemical liquid-phase electron microscopy, operando X-ray methods, and scanning electrochemical probe microscopies have the potential to lead to major breakthroughs in the development of next-generation energy materials.