Unraveling the Local Coordination Effect of Cu-N-C Single-Atom Catalyst towards CO Adsorption via Gas-Phase Cluster Model Approach

Abstract

The current understanding regarding how the coordination environment of single-atom catalyst supported on nitrogen-doped carbon (M-N-C SACs) regulates its reactivity remains controversial, due to the complicated surface chemistry and lack of molecular-level insights. Here we introduced an experimental modeling approach to unambiguously identify the individual contribution of local environment to the adsorption activity of CO on Cu-N-C system. The fundamental intrinsic activities of Cu-N-C with different N coordination numbers, N coordination geometries (e.g., pyrrolic N and pyridinic N), defect sites (e.g., armchair and zig-zag), as well as S and P dopants, towards CO adsorption can be explicitly obtained and compared at strictly atomic level, which would be challenging to access via conventional techniques in SACs research. For all kind of coordination structures, we further identified general rules that control CO adsorption strength and experimental reaction rate. This novel approach is general which can be applied to other SAC metal and reaction systems.