In situ observation of reactive oxygen species forming on oxygen-evolving iridium surfaces.

ABSTRACT: Water splitting performed in acidic media relies on the exceptional performance of iridium-based materials to catalyze the oxygen evolution reaction (OER). In the present work, we use in situ X-ray photoemission and absorption spectroscopy to resolve the long-standing debate about surface species present in iridium-based catalysts during the OER. We find that the surface of an initially metallic iridium model electrode converts into a mixed-valent, conductive iridium oxide matrix during the OER, which contains O^II- and electrophilic O^I- species. We observe a positive correlation between the O^I- concentration and the evolved oxygen, suggesting that these electrophilic oxygen sites may be involved in catalyzing the OER. We can understand this observati

SUBMITTER: Pfeifer V 

PROVIDER: S-EPMC5407268 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature