(98d) Characterizing Dynamic Materials for Electrocatalytic Processes

Research in the Seitz lab aims to revolutionize catalytic processes at the foundation of our energy and chemical industries that are currently major drivers of climate change. Electrocatalytic processes provide unique opportunities to integrate renewable electricity sources as well as tune catalyst response and reaction efficiency via applied electric potentials, solvent effects, and electrochemical double layer effects. Progress in this area is impeded by many factors, including knowledge gaps of complex catalyst material dynamics and degradation under reaction conditions. We seek to fill these gaps using a combination of electrochemistry, spectroscopy, and materials science towards the development of catalyst materials and reactor systems with enhanced activity, selectivity, and stability.

We use controlled material syntheses and advanced spectroscopy techniques to monitor dynamic behavior of catalysts in response to reaction conditions. Notably, we have developed several iridium-based perovskite materials to establish electronic structure effects associated with systematic changes in composition, crystallinity, and strain. We use these materials to elucidate trends in structural reorganization and degradation mechanisms induced by varied operating conditions, exemplified with water splitting reactions. We also investigate contributions of substrate instability to the overall electrode performance and employ intrinsic material stability metrics to separately assess substrate vs. catalyst material stability over various time scales. We further explore catalyst material response to reaction conditions at varied time scales using ex situ, in situ, and operando x-ray absorption spectroscopy to provide insightful, element-specific electronic and geometric structure information. Direct comparison of ex situ vs. in situ/operando measurements also highlights the impacts of different experimental platforms and the effects of removing catalysts from reaction conditions.