Perylenediimide-Incorporated Covalent Triazine Framework: A Highly Conductive Carbon Support for Copper Single-Atom Catalysts in Electrocatalytic CO₂ Conversion

Abstract

Here, we show that a perylenediimide-incorporated covalent triazine framework (PDI-CTF) leads to an adequate conductive carbon support for copper single-atom catalysts (Cu-SACs), allowing the selective electroreduction of CO2 to methanol. CTF-Cu-SACs converted CO2 into methanol with a faradaic efficiency of 72.6% at a low overpotential (0.2 V vs RHE). While increasing the overpotential (0.2 to −0.4 V vs RHE), CTF-Cu-SACs promoted syngas (CO and H2) production with faradaic efficiencies of 53.2 and 39.5%, respectively. Moreover, CTF-Cu-SACs led to robust catalytic stability for 20 h of continuous electrolysis in an aqueous solution. Notably, it was observed that additional nitrogen doping to the PDI-CTF profoundly influences product selectivity, possibly due to the synergetic effect of highly conductive pyrolyzed CTF and N-chelating ligands with rich active sites. Our results indicate that the PDI-CTF-based Cu-SACs provide abundant active sites for CO2 adsorption, thus enhancing intermolecular ion and charge transportation that efficiently reduces CO2 into methanol in an aqueous system.