Hashemi, Negah Shah, Jafar Hussain Hu, Cejun Nandy, Subhajit Aleshkevych, Pavlo Farid, Sumbal Chae, Keun Hwa Xie, Wei Liu, Taifeng Wang, Junhu Najafpour, Mohammad Mahdi 2024-01-19T08:00:23Z 2024-01-19T08:00:23Z 2024-01-04 2024-02 2095-4956 https://pubs.kist.re.kr/handle/201004/112939 This study investigates the effects of Fe on the oxygen-evolution reaction (OER) in the presence of Au. Two distinct areas of OER were identified: the first associated with Fe sites at low overpotential (approximate to 330 mV), and the second with Au sites at high overpotential (approximate to 870 mV). Various factors such as surface Fe concentration, electrochemical method, scan rate, potential range, concentration, method of adding K2FeO4, nature of Fe, and temperature were varied to observe diverse behaviors during OER for FeOxHy/Au. Trace amounts of Fe ions had a significant impact on OER, reaching a saturation point where the activity did not increase further. Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) analyses. In situ visible spectroscopy confirmed the formation of FeO42- during OER. In situ Mossbauer and surface-enhanced Raman spectroscopy (SERS) analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER. A lattice OER mechanism based on FeOxHy was proposed for operation at low overpotentials. Density functional theory (DFT) calculations revealed that Fe oxide, Fe-oxide clusters, and Fe doping on the Au foil exhibited different activities and stabilities during OER. The study provides insights into the interplay between Fe and Au in OER, advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems. (c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved. English Elsevier BV Toward a comprehensive hypothesis of oxygen-evolution reaction in the presence of iron and gold Article 10.1016/j.jechem.2023.09.033 1 Journal of Energy Chemistry, v.89, pp.172 - 183 Journal of Energy Chemistry 89 172 183 N scie scopus 001123093700001 Chemistry, Applied Chemistry, Physical Energy & Fuels Engineering, Chemical Chemistry Energy & Fuels Engineering Article X-RAY-ABSORPTION LAYERED DOUBLE HYDROXIDE WATER-OXIDATION ELECTROCHEMICAL EVOLUTION ASSISTED SYNTHESIS REACTION-MECHANISM OXIDE CATALYSTS NICKEL-OXIDE FE-SITES ELECTROCATALYSIS Oxygen evolution Water oxidation DFT calculation Fe/Au electrocatalysis Mechanism