Affiliation:
1. Key Laboratory of Photochemistry Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China
2. University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. Heifei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei Anhui 230026 P. R. China
Abstract
AbstractHerein we report the vital role of spin polarization in proton‐transfer‐mediated water oxidation over a magnetized catalyst. During the electrochemical oxygen evolution reaction (OER) over ferrimagnetic Fe3O4, the external magnetic field induced a remarkable increase in the OER current, however, this increment achieved in weakly alkaline pH (pH 9) was almost 20 times that under strongly alkaline conditions (pH 14). The results of the surface modification experiment and H/D kinetic isotope effect investigation confirm that, at weakly alkaline pH, during the nucleophilic attack of FeIV=O by molecular water, the magnetized Fe3O4 catalyst polarizes the spin states of the nucleophilic attacking intermediates. The spin‐enhanced singlet O−H cleavage and triplet O−O bonding occur synergistically, which promotes the O2 generation more significantly than the strongly alkaline case involving only spin‐enhanced O−O bonding.
Funder
Science Fund for Distinguished Young Scholars of Fujian Province
National Natural Science Foundation of China
National Science and Technology Program during the Twelfth Five-year Plan Period