Hong-Jun Gao, Shengnan Sun, Tianze Wu, Junling Wang, Yuanmiao Sun, Haitao Yang, Xiao Ren, Guoyu Xian, Zhichuan J. Xu, Chengmin Shen, Adrian C. Fisher, Günther G. Scherer, Joel W. Ager, Daniel Mandler, Alexis Grimaud, Jose Gracia, Wu, Tianze [0000-0001-7123-6844], Scherer, Günther G. [0000-0001-6526-4777], Ager, Joel W. [0000-0001-9334-9751], Grimaud, Alexis [0000-0002-9966-205X], Yang, Haitao [0000-0003-4304-9835], Gracia, Jose [0000-0001-7744-8872], Gao, Hong-Jun [0000-0001-9323-1307], Xu, Zhichuan J. [0000-0001-7746-5920], Apollo - University of Cambridge Repository, Scherer, Günther G [0000-0001-6526-4777], Ager, Joel W [0000-0001-9334-9751], Xu, Zhichuan J [0000-0001-7746-5920], School of Mathematical Sciences [Fudan], Fudan University [Shanghai], Institut Pascal (IP), SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Department of Chemical Engineering, University of Cambridge [UK] (CAM), Institute of Chemistry, The Hebrew University of Jerusalem, The Hebrew University of Jerusalem (HUJ), Chimie du solide et de l'énergie (CSE), Collège de France (CdF (institution))-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), School of Materials Science and Engineering [Singapore], Nanyang Technological University [Singapour], and Jiangsu Institute of Parasitic Diseases
Producing hydrogen by water electrolysis suffers from the kinetic barriers in the oxygen evolution reaction (OER) that limits the overall efficiency. With spin-dependent kinetics in OER, to manipulate the spin ordering of ferromagnetic OER catalysts (e.g., by magnetization) can reduce the kinetic barrier. However, most active OER catalysts are not ferromagnetic, which makes the spin manipulation challenging. In this work, we report a strategy with spin pinning effect to make the spins in paramagnetic oxyhydroxides more aligned for higher intrinsic OER activity. The spin pinning effect is established in oxideFM/oxyhydroxide interface which is realized by a controlled surface reconstruction of ferromagnetic oxides. Under spin pinning, simple magnetization further increases the spin alignment and thus the OER activity, which validates the spin effect in rate-limiting OER step. The spin polarization in OER highly relies on oxyl radicals (O∙) created by 1st dehydrogenation to reduce the barrier for subsequent O-O coupling., Water oxidation to triplet oxygen requires a spin polarization process for faster kinetics. Here, the authors show an interface spin pinning effect between ferromagnetic oxides and reconstructed oxyhydroxide surface layer, where the spin ordering in paramagnetic oxyhydroxide catalyst layer can be tuned to improve the intrinsic activity.