Enhancing Oxygen Evolution Reaction via a Surface Reconstruction-Induced Lattice Oxygen Mechanism
Subin Choi, Sejun Kim, Sunghoon Han, Jian Wang, Juwon Kim, Bonho Koo, Alexander A. Ryabin, Sebastian Kunze, Hyejeong Hyun, Jeongwoo Han, Shu-Chih Haw, Keun Hwa Chae, Chang Hyuck Choi, Hyungjun Kim, Jongwoo Lim
Abstract
Systematic control of surface reconstruction during catalysis remains challenging. Particularly, inducing a surface structure reconstruction following the lattice oxygen oxidation mechanism (LOM), which can reduce the overpotential in oxygen evolution reaction (OER) catalysts, has not been extensively investigated. The mechanism of the OER of transition-metal-oxide-based catalysts can be facilitated by manipulating the local coordination structure to modulate the reactivity of lattice oxygen. Herein, we report an in situ surface reconstruction strategy by doping F into LaNiO 3 to distort the NiO 6 octahedral sites, weaken the Ni–O bonds, and increase lattice oxygen reactivity during OER. The as-prepared LaNiO 2.9 F 0.1 exhibits enhanced performances toward OER with a low overpotential of 320 mV at 10 mA cm –2, a small Tafel slope of 78 mV dec –1, and good long-term stability in alkaline media. Comprehensive analysis reveals that the in situ self-reconstructed surface favors the LOM pathway for the OER, resulting in a considerably improved performance. These results demonstrate that the lattice oxygen acts as a switch for directing the OER mechanism, and further, controlling the lattice oxygen reactivity emerges as a promising approach for dynamic self-reconstruction to highly active OER electrocatalysts.