de Araffljo, Jorge Ferreira Dionigi, Fabio Merzdorf, Thomas Oh, Hyung-Suk Strasser, Peter 2024-01-19T14:32:10Z 2024-01-19T14:32:10Z 2022-01-10 2021-06 1433-7851 https://pubs.kist.re.kr/handle/201004/116901 Water oxidation is a crucial reaction for renewable energy conversion and storage. Among the alkaline oxygen evolution reaction (OER) catalysts, NiFe based oxyhydroxides show the highest catalytic activity. However, the details of their OER mechanism are still unclear, due to the elusive nature of the OER intermediates. Here, using a novel differential electrochemical mass spectrometry (DEMS) cell interface, we performed isotope-labelling experiments in O-18-labelled aqueous alkaline electrolyte on Ni(OH)(2) and NiFe layered double hydroxide nanocatalysts. Our experiments confirm the occurrence of Mars-van-Krevelen lattice oxygen evolution reaction mechanism in both catalysts to various degrees, which involves the coupling of oxygen atoms from the catalyst and the electrolyte. The quantitative charge analysis suggests that the participating lattice oxygen atoms belong exclusively to the catalyst surface, confirming DFT computational hypotheses. Also, DEMS data suggest a fundamental correlation between the magnitude of the lattice oxygen mechanism and the faradaic efficiency of oxygen controlled by pseudocapacitive oxidative metal redox charges. English John Wiley & Sons Ltd. Evidence of Mars-Van-Krevelen Mechanism in the Electrochemical Oxygen Evolution on Ni-Based Catalysts Article 10.1002/anie.202101698 1 Angewandte Chemie International Edition, v.60, no.27, pp.14981 - 14988 Angewandte Chemie International Edition 60 27 14981 14988 Y scie scopus 000654761100001 2-s2.0-85106633504 Chemistry, Multidisciplinary Chemistry Article WATER OXIDATION NICKEL OXYHYDROXIDE REACTION DYNAMICS LATTICE OXYGEN REDOX STATES IRON ELECTROCATALYSTS SPECTROSCOPY IMPURITIES HYDROXIDE alkaline OER catalyst differential electrochemical mass spectrometry isotope O-18 lattice oxygen evolution