Boosting C2+ Selectivity in CO₂ Electroreduction on Cu Nanoparticles via Molecular Dispersion of Cobalt Phthalocyanine

Cu-based tandem catalysts have been widely studied due to their excellent performance in electrocatalytic reduction of carbon dioxide (CO2RR) to produce C2+ products. However, during the CO2RR process, Cu atoms face the issue of dynamic restructuring, resulting in relatively poor stability and single-product selectivity. Herein, Cobalt phthalocyanine (CoPc) was integrated with Cu nanoparticles (NPs) to prepare a tandem catalyst (Cu/CoPcx) by in-situ growth method, significantly enhancing the selectivity of Cu-based catalysts for C2+ products. The optimal material, Cu/CoPc0.004, achieved a Faradaic efficiency (FE) of 73.17% for C2+ products, with a C2+ product current density exceeding 377 mA/cm2. More importantly, tandem catalyst Cu/CoPc0.004 exhibits high selectivity for ethylene, achieving a FE of 52.35% at -1.26 V (versus reversible hydrogen electrode) with a high ethylene current density (270 mA/cm2). The experimental results indicate that the interaction between CoPc and Cu NPs introduces numerous oxygen vacancies and stabilizes the presence of Cu+. Moreover, the unique structure of the cascade catalyst enables CoPc to provide a large amount of CO intermediates for Cu active sites, thus promoting C-C coupling and facilitating the formation of C2+ products.