Unveiling the potential-dependent evolution of the electronic structure of Cu-N-C model catalyst for electrochemical nitrate reduction react

Copper-based catalysts play a crucial role in many catalytic reactions ranging from biological electron-transfer process to electrosynthesis of chemicals. A prominent example is the utilization of Cu single atoms coordinated with nitrogen-doped carbon (Cu-N-C) materials in electrochemical nitrate reduction reaction (eNO3-RR). Investigating the potential-dependent dynamic evolution of electronic structure of Cu center is paramount for a comprehensive understanding of its adsorption behaviour and unveiling the fundamental multiple electron-transfer processes. Herein, we propose performing in-situ HERFD-XAS characterization of Cu-N-C model catalyst for eNO3-RR. Through interpreting the evolution of pre-edge and rising edge features in HERFD-XANES spectra, we aim to address two fundamental questions: 1. How does the geometric configuration and oxidation state of Cu center evolve under varying potentials? 2. What is the impact of adsorbates at different stages, with and without NO3-?