Sluggish reaction kinetics to split water into hydrogen and oxygen are hindering the market penetration of water electrolyzers for renewable energy storage.¹ It is therefore of paramount importance to design the next generation of electrocatalysts, which offer enhanced performance and maximize catalyst utilization, while guaranteeing a durability of approximately 50.000 hours. However, current synthesis and characterization methods for electrocatalysts are not satisfactory. In particular, innovative and transformative characterization methods are required to provide a detailed experimental understanding of physical-chemical/electrochemical relations between the atomic structures of electrocatalysts and their activity, stability and degradation.²

Here, we show how in situ transmission electron microscopy (TEM) and identical-location TEM can be used to follow dynamic changes in electrocatalyst morphology, faceting and elemental segregation under real electrochemical working conditions. We study the relationship between nanoparticle morphology, composition and activity and demonstrate the ability to tune the structure-stability relationships of bimetallic nanoparticles for use as electrocatalysts.

References

(1) Carmo, M.; Fritz, D. L.; Mergel, J.; Stolten, D. A Comprehensive Review on PEM Water Electrolysis. Int. J. Hydrogen Energy 2013, 38 (12), 4901–4934.

(2) Shviro, M.; Gocyla, M.; Schierholz, R.; Tempel, H.; Kungl, H.; Eichel, R. A.; Dunin-Borkowski, R. E. Transformation of Carbon-Supported Pt-Ni Octahedral Electrocatalysts into Cubes: Toward Stable Electrocatalysis. Nanoscale 2018, 10 (45), 21353–21362.