Understanding the Reaction Activity of Ni(1-x)FexOH Towards Oxygen Evolution Reaction

The development of electrocatalysts towards the oxygen evolution reaction based on earth-abundant and cheap materials, such as transition metal oxide and hydroxide, is crucial to reduce the emission of CO 2 and slowdown the global warming 1. Among these transition metal compounds, ferromagnetic electrocatalysts usually exhibit promising activities towards OER due to their unique electron spin properties 2. Applying an external magnetic field can further tune the electron spin polarization of ferromagnetic materials and, therefore, improve the OER activity. However, evaluating the activity of these electrocatalysts towards OER remains challenging. For example, the electrocatalysts will undergo activation under reaction conditions (frequently due to Fe insertion), which brings difficulties in determining the real reaction sites as well as establishing the “structure-activity” relationship 3. In addition, the overall measure activity (current density) is contributed by multiple factors such as intrinsic kinetics, mass transfer, conductivity, etc., which strongly depend on operation conditions. In this talk, I will present our recent study of OER on Ni (1-x) Fe x OH 4. Electrochemical impedance spectroscopy (EIS) and quasi-in situ XPS will be applied to obtain the contribution from different reaction parameters and understand the intrinsic activity. 1 McCrory, C. C. L. et al. Benchmarking Hydrogen Evolving Reaction and Oxygen Evolving Reaction Electrocatalysts for Solar Water Splitting Devices. Am. Chem. Soc. 137 , 4347–4357 (2015). 2 Ren, X. et al. Spin-polarized oxygen evolution reaction under magnetic field. Commun. 12 , 1–12 (2021). 3 Jung, S., McCrory, C. C. L., Ferrer, I. M., Peters, J. C. & Jaramillo, T. F. Benchmarking nanoparticulate metal oxide electrocatalysts for the alkaline water oxidation reaction. Mater. Chem. A 4 , 3068–3076 (2016) 4 Wei Chen, Laura Donk, Tiago Fernandes, Anna Kitayev, ErvinTal Gutelmacher, Yury V. Kolen’ko, Marta C. Figueiredo * , in preparation.