Uncovering Dynamic Edge-Sites in Atomic Co-N-C Electrocatalyst for Selective Hydrogen Peroxide Production.
Jinwen HuWenzhe ShangCuncun XinJingya GuoXusheng ChengSonglin ZhangSuchan SongWei LiuFeng JuJungang HouYantao ShiPublished in: Angewandte Chemie (International ed. in English) (2023)
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 Co 2+ , in contrast to the rigid in-plane embedded Co 1 -N x counterpart. Theoretical calculations demonstrate that the synergistic interplay of in situ reconstructed Co 1 -N 2 -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 H 2 O 2 production.
Keyphrases
- hydrogen peroxide
- molecular dynamics
- electron transfer
- nitric oxide
- metal organic framework
- aqueous solution
- molecular docking
- magnetic resonance
- density functional theory
- quantum dots
- molecular dynamics simulations
- magnetic resonance imaging
- ionic liquid
- highly efficient
- transition metal
- contrast enhanced
- drug delivery