Now, Jakub Drnec, Brian Seger and co-workers report on an advanced operando X-ray characterization platform that integrates synchrotron wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS) and X-ray fluorescence to track the evolution of catalyst particles along with ion and water movement in MEA-based CO2 electrolysis. To mimic long-term stability testing under realistic conditions, the team developed a pulsed-electrochemistry-driven accelerated stress test (AST) method for CO2 electrolysis. This innovative approach not only suppresses salt precipitation at high current densities but also accelerates degradation by approximately sixfold compared with conventional tests, dramatically shortening the time required for stability assessments. Moreover, the authors introduce a new metric, the D ratio, defined as the SAXS-derived diameter divided by the WAXS-derived diameter, as a valuable indicator for evaluating the dispersion uniformity of catalysts, using Ag and Au nanoparticles as model systems. In this work, Au nanoparticles exhibited a lower D value, indicating a more stable crystalline phase and stronger catalyst–substrate adhesion compared with Ag nanoparticles under the pulsed-electrochemistry-driven AST.
Overall, this work establishes a customized operando X-ray characterization platform coupled with a pulsed-electrochemistry-driven AST technique to diagnose degradation mechanisms within MEA-based CO2 electrolyzers. Beyond advancing the design of high-efficiency, durable CO₂ electroreduction systems, this integrated methodology holds broad promise for probing degradation pathways across diverse electrochemical technologies.
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