Three early-career CorMic principal advisors show how correlative operando microscopy can reveal electrocatalyst degradation across scales
Electrocatalysts are not static materials. During operation, their surfaces restructure, particles dissolve or agglomerate, and active sites emerge or disappear. Understanding these dynamic processes is essential for developing durable catalysts for sustainable energy technologies. However, every microscopy method captures only part of this evolution, and the measurement itself may even alter the system being studied.
In a recent open-access Mini-Review published in Nano Letters, the three early-career CorMic principal advisors Andreas Hutzler, Siow Woon Ng and Johannes Will examine how these limitations can be overcome through correlative microscopy. The authors bring together expertise from CorMic projects A1, A3 and B5. The publication also closely connects to the cross-cutting postdoctoral Project P, which implements modern synchrotron-based scattering, spectroscopy and 3D characterization methods within CorMic’s research and qualification program.
The Mini-Review focuses on three complementary approaches. Liquid-phase electron microscopy directly visualizes nanoscale processes such as particle dissolution, coalescence and restructuring, but electron-beam-induced radiolysis, restricted sample geometries and limited statistics complicate interpretation. Operando X-ray methods probe larger sample volumes under more realistic conditions and provide statistically robust information about crystallinity, morphology and chemical states, but are generally spatially averaged and may themselves induce radiation effects. Scanning electrochemical probe microscopies map local activity at individual grains, facets, grain boundaries or defects, while providing only limited information about the underlying structural changes.
The central message is therefore that no individual technique can provide the complete picture. In correlative workflows, local observations from electron microscopy can be benchmarked against statistically representative X-ray data. Electrochemical activity maps can be combined with microscopy at identical locations to connect catalytic performance with nanoscale structure. Comparisons between miniature liquid cells, X-ray model reactors and larger devices can furthermore help distinguish genuine degradation mechanisms from mass-transport effects or measurement artifacts.
The publication thus captures the scientific heart of CorMic: complementary information from different methods, operating environments and length scales must be correlated to achieve a deeper and more reliable understanding of functional materials. Projects A1, A3 and B5 establish such workflows for electron microscopy, electrochemical characterization and hierarchical electrolyzer materials, while Project P contributes the required synchrotron expertise across the RTG. Together, these activities bridge the gap between nanoscale observations, statistically representative measurements and realistic devices – providing the mechanistic understanding needed for the accelerated development of next-generation energy materials.