Elucidating the Discrepancy between the Intrinsic Structural Instability and the Apparent Catalytic Steadiness of M-N-C Catalysts toward Oxygen Evolution Reaction.
Jinyan CaiXiaobin HaoZenan BianYishang WuCong WeiXuanwei YinBo LiuMing FangYouming LvYufang XieYanyan FangGong-Ming WangPublished in: Angewandte Chemie (International ed. in English) (2024)
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.
Keyphrases
- density functional theory
- metal organic framework
- molecular dynamics
- transition metal
- highly efficient
- high resolution
- electron transfer
- diffusion weighted imaging
- crystal structure
- molecular dynamics simulations
- ionic liquid
- mass spectrometry
- gold nanoparticles
- single molecule
- anaerobic digestion
- municipal solid waste