Fe-S dually modulated adsorbate evolution and lattice oxygen compatible mechanism for water oxidation
Xu Luo, Hongyu Zhao, Xin Tan, Lin Sheng, Kesong Yu, Xueqin Mu, Zhenhua Tao, Pengxia Ji, Shichun Mu
Abstract
Simultaneously activating metal and lattice oxygen sites to construct a compatible multi-mechanism catalysis is expected for the oxygen evolution reaction (OER) by providing highly available active sites and mediate catalytic activity/stability, but significant challenges remain. Herein, Fe and S dually modulated NiFe oxyhydroxide (R-NiFeOOH@SO4) is conceived by complete reconstruction of NiMoO4·xH2O@Fe,S during OER, and achieves compatible adsorbate evolution mechanism and lattice oxygen oxidation mechanism with simultaneously optimized metal/oxygen sites, as substantiated by in situ spectroscopy/mass spectrometry and chemical probe. Further theoretical analyses reveal that Fe promotes the OER kinetics under adsorbate evolution mechanism, while S excites the lattice oxygen activity under lattice oxygen oxidation mechanism, featuring upshifted O 2p band centers, enlarged d-d Coulomb interaction, weakened metal-oxygen bond and optimized intermediate adsorption free energy. Benefiting from the compatible multi-mechanism, R-NiFeOOH@SO4 only requires overpotentials of 251 ± 5/291 ± 1 mV to drive current densities of 100/500 mA cm−2 in alkaline media, with robust stability for over 300 h. This work provides insights in understanding the OER mechanism to better design high-performance OER catalysts. The oxygen evolution reaction is crucial for energy conversion but faces challenges in catalyst optimization. Here, the authors present a dual-modulated NiFe oxyhydroxide (R-NiFeOOH@SO4) that enhances OER performance through optimized metal and lattice oxygen sites, achieving a compatible multi-mechanism.