Accelerated proton transmission in metal–organic frameworks for the efficient reduction of CO2 in aqueous solutions

Abstract

Metal–organic frameworks (MOFs) have exhibited huge potential in the field of CO₂ electroreduction but highly stable and active ones are still scarce. This study reports a (5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato)-Fe(III) chloride (FeTCPPCl) co-building UiO-66 electrocatalyst for CO₂ reduction in an aqueous solution. In situ X-ray absorption spectroscopy (XAS) measurements characterized its robust structure under catalysis. The unique framework of UiO-66 provides the available proton facilitator for improving CO₂ reduction activity on iron porphyrin, and a concerted proton–electron transfer (CPET) mechanism might be considered for the catalytic pathway, achieving the highest faradaic efficiency of nearly 100% at an overpotential of 450 mV for turning CO₂ to CO in the reported MOFs.