电催化剂
催化作用
化学
离解(化学)
过氧化氢
氧烷
吸附
光化学
选择性
价(化学)
X射线吸收精细结构
氢
红外光谱学
光谱学
无机化学
物理化学
电化学
电极
有机化学
物理
量子力学
作者
Jinwen Hu,Wenzhe Shang,Cuncun Xin,Jingya Guo,Xusheng Cheng,Songlin Zhang,Suchan Song,Wei Liu,Feng Ju,Jungang Hou,Yantao Shi
标识
DOI:10.1002/anie.202304754
摘要
Understanding the nature of single-atom catalytic sites and identifying their spectroscopic fingerprints are essential prerequisites for the rational design of target catalysts. Here, we apply correlated in situ X-ray absorption and infrared spectroscopy to probe the edge-site-specific chemistry of Co-N-C electrocatalyst during the oxygen reduction reaction (ORR) operation. The unique edge-hosted architecture affords single-atom Co site remarkable structural flexibility with adapted dynamic oxo adsorption and valence state shuttling between Co(2-δ)+ and Co2+ , in contrast to the rigid in-plane embedded Co1 -Nx counterpart. Theoretical calculations demonstrate that the synergistic interplay of in situ reconstructed Co1 -N2 -oxo with peripheral oxygen groups gives a rise to the near-optimal adsorption of *OOH intermediate and substantially increases the activation barrier for its dissociation, accounting for a robust acidic ORR activity and 2e- selectivity for H2 O2 production.
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