Nanocavity-confined Cu2O in a porphyrin-based MOF for steering CO2 electroreduction toward hydrocarbons

Abstract

The electrocatalytic conversion of CO₂ to hydrocarbon compounds still faces fundamental challenges, including the high activation barrier of CO₂ and insufficient selectivity toward C₂₊ products. This study constructs a composite catalyst (Cu₂O@PCN-223) for efficient electrocatalytic CO₂ reduction utilizing the nanoconfinement of a metal–organic framework (MOF) to regulate the dispersion of Cu₂O and the modulate reaction intermediates. Structural characterization confirms the uniform distribution of Cu₂O within the lattice of PCN-223, with interfacial electronic interactions significantly enhancing charge transfer and catalytic activity. The optimized catalyst demonstrates remarkable hydrocarbon selectivity, delivering Faradaic efficiencies (FEs) of 38.7% for CH₄ and 48.7% for C₂H₄ at −1.3 V vs. RHE, with a total hydrocarbon FE reaching 87.4%, which is 6–7 times higher than that of pristine Cu₂O. DFT calculations demonstrate that the MOF-confined microenvironment selectively promotes C₂ production by stabilizing the key intermediates (*CO and *CHO) and facilitating charge transfer during C–C coupling, establishing a strategic design paradigm for efficient CO₂-to-hydrocarbon conversion.