Porous metal-porphyrin triazine-based frameworks for efficient CO₂ electroreduction

Abstract

Electrochemical reduction of CO₂ (ECR-CO₂) into high value-added products plays a crucial role in energy conversions. Herein, we developed a family of porous metal-porphyrin triazine-based frameworks (MPTFs-x, M = Mn, Fe, Co, Ni, and Cu, x = temperature) with a specific surface area up to 977 m² g⁻¹ and homogenously dispersed transition-metals. Benefiting from a high content of N species of 8.43 at.% and abundantly exposed Ni-Nₓ active sites, NiPTFs-600 displayed a superb Faradaic efficiency (FE) of CO production (>90 %) in the range of −0.55 V to −0.95 V with the maximum FE of 97.6 % and current density of 10.8 mA cm⁻² at −0.8 V. The reaction mechanism was found to be the adsorption of CO₂ molecules to form *CO₂ intermediates, accompanied by successive protonation to produce *COOH and then *CO