Elucidating the Discrepancy between the Intrinsic Structural Instability and the Apparent Catalytic Steadiness of M‐N‐C Catalysts toward Oxygen Evolution Reaction
Jinyan Cai, Xiaobin Hao, Zenan Bian, Yishang Wu, Cong Wei, Xuanwei Yin, Бо Лю, Ming Fang, Youming Lv, Yufang Xie, Yufang Xie, Yanyan Fang, Yanyan Fang, Gongming Wang
Abstract
Despite the widespread investigations on the M-N-C type single atom catalysts (SACs) for oxygen evolution reaction (OER), an internal conflict between its intrinsic thermodynamically structural instability and apparent catalytic steadiness has long been ignored. Clearly unfolding this contradiction is necessary and meaningful for understanding the real structure-property relation of SACs. Herein, by using the well-designed pH-dependent metal leaching experiments and X-ray absorption spectroscopy, an unconventional structure reconstruction of M-N-C catalyst during OER process was observed. Combining with density functional theory calculations, the initial Ni-N coordination is easily broken in the presence of adsorbed OH*, leading to favorable formation of Ni-O coordination. The formed Ni-O works stably as the real active center for OER catalysis in alkaline media but unstably in acid, which clearly explains the existing conflict. Unveiling the internal contradiction between structural instability and catalytic steadiness provides valuable insights for rational design of single atom OER catalysts.