Electroreduction of CO 2 on Single-Site Copper-Nitrogen-Doped Carbon Material: Selective Formation of Ethanol and Reversible Restructuration of the Metal Sites

摘要: It is generally believed that CO2 electroreduction to multi-carbon products such as ethanol or ethylene may be catalyzed with significant yield only on metallic copper surfaces, implying large ensembles of atoms. Here, we report an inexpensive Cu-N-C material prepared via a simple pyrolytic route exclusively feature single atoms CuN4 coordination environment, atomically dispersed in nitrogen-doped conductive carbon matrix. This achieves aqueous at Faradaic 55 % under optimized conditions (electrolyte: 0.1 m CsHCO3 , potential: -1.2 V vs. RHE and gas-phase recycling set up), well CO C2 -products (ethanol ethylene) 80 %. During electrolysis the isolated sites transiently convert into nanoparticles, shown by operando XAS analysis, which are likely catalytically active species. Remarkably, this process reversible initial recovered intact after electrolysis.