Operando characterization of catalyst nanoparticle decay pathways during high current CO2 electrolysis accelerated stress tests

In this proposal, we will use high energy/flux complementary synchrotron radiation techniques at beamline ID31 to systematically investigate how catalyst type and corresponding NP size affects cathode catalyst layer stability and CO2 electrolysis performance under reported accelerated stress tests (ASTs). Simultaneously, building upon our previous work at ESRF, we will track water and ionic distributions throughout the MEA at different stages during the ASTs to differentiate catalyst decay mechanisms from changes in mass transport-related decay, which may arise from physical gas diffusion electrode (GDE) degradation leading to changes in properties such as porosity and hydrophobicity. Overall, in this proposal we seek to understand state-of-the-art CO2 electrolysis device degradation mechanisms through AST protocols by probing the operando chemical and morphological changes to the catalyst layer and its local hydration environment during operation.