Abstract:
Electrocatalysis has the potential to enable sustainable chemical infrastructures via the generation of commodity chemicals such as hydrogen, hydrocarbons, and ammonia with renewable energy, but electrochemical devices such as electrolyzers often exhibit inadequate activity and stability for these transformations due to poor catalyst performance for the oxygen evolution reaction (OER). The Moreno-Hernandez Laboratory specializes in the design of electrocatalysts for next-generation energy devices via a multiscale feedback loop that integrates the precise synthesis of nanomaterials, atomic-scale observations of structural dynamics in liquid environments with in situ transmission electron microscopy, and the assessment of electrocatalyst performance under relevant operating conditions via proton exchange membrane water electrolysis. Insights from these activities, in particular with liquid phase transmission electron microscopy (LP-TEM), has resulted in the direct observation of electrocatalyst degradation mechanisms and degradation kinetics at the nanoscale, and the observation of collective atomic-scale mechanisms of dissolution. Disorder-induced degradation has been found to result in substantial nanoscale heterogeneity in dissolution properties for rutile-type electrocatalysts such as RuO2 and IrO2. Insights from these activities has resulted in the discovery of oxidized overlayer electrocatalysts with improved noble metal utilization, the discovery of experimental energy scaling relations that can guide catalyst design for non-iridium electrocatalysts, the direct observation of electrocatalyst degradation mechanisms at the nanoscale, and the observation of atomic-scale mechanisms of dissolution. Our studies highlight the importance of multimodal approaches to guide electrocatalyst design and motivate further study of nanoscale and chemical effects that can be harnessed to design efficient, earth-abundant, and stable electrocatalysts for electrochemical transformations.
Event Series
DMI Seminar Series