The effect of surface orientations on the formation of iridium oxide species during the oxygen evolution reaction (OER) remains yet unknown. Herein, we use a needle‐shaped iridium atom probe specimen as a nanosized working electrode to ascertain the role of the surface orientations in the formation of oxide species during OER. At the beginning of electrolysis, the top 2–3 nm of (024), (026), (113), and (115) planes are covered by IrO−OH, which activates all surfaces towards OER. A thick subsurface oxide layer consisting of sub‐stoichiometric Ir−O species is formed on the open (024) planes as OER proceeds. Such metastable Ir−O species are thought to provide an additional contribution to the OER activity. Overall, this study sheds light on the importance of the morphological effects of iridium electrocatalysts for OER. It also provides an innovative approach that can directly reveal surface species on electrocatalysts at atomic scale.
The effect of surface orientations on the formation of iridium oxide species during the oxygen evolution reaction (OER) remains yet unknown. Herein, we use aneedle-shaped iridium atom probe specimen as ananosized working electrode to ascertain the role of the surface orientations in the formation of oxide species during OER. At the beginning of electrolysis, the top 2-3 nm of ( 024), ( 026), ( 113), and (115) planes are covered by IrOÀOH, which activates all surfaces towards OER. At hicks ubsurface oxide layer consisting of substoichiometric IrÀOspecies is formed on the open (024) planes as OER proceeds.Such metastable Ir À Ospecies are thought to providea na dditional contribution to the OER activity. Overall, this study sheds light on the importance of the morphological effects of iridium electrocatalysts for OER. It also provides an innovative approach that can directly reveal surface species on electrocatalysts at atomic scale.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.