Interplay of [C ₆₀ ]Fullerene and Cu ₂ O Nanocrystals for Stable CO ₂ Electroreduction to C ₂₊ Products

High Resolution Image Download MS PowerPoint Slide Copper oxides such as Cu 2 O are promising catalysts for the electrochemical CO 2 reduction reaction (CO 2 RR) to C 2+ products, yet their intrinsic susceptibility to Cu + reduction and morphology degradation severely limits their long-term performance. Herein, we report a facile two-step wet-chemical route to interface [C 60 ]fullerene with cubic Cu 2 O ( c -Cu 2 O), octahedral ( o -Cu 2 O), and dodecahedral ( d -Cu 2 O) crystals. The resulting composite optimal c -Cu 2 O–C 60 achieves substantial Faradaic efficiencies of 60.4% in an H-cell and 65.6% in a flow-cell for C 2+ products, which is 3-fold higher than pristine c -Cu 2 O, while maintaining stable operation for 100 h at –1.2 V versus RHE without detectable activity loss. Our experimental results and theoretical study demonstrate that the strategic incorporation of C 60 during the synthesis of Cu 2 O directly endows the surfaces of the resultant Cu 2 O crystals with abundant Cu + /Cu 0 grain boundaries. Additionally, the presence of C 60 induces the formation of more Cu + /Cu 0 boundaries during the CO 2 RR process, which synergistically facilitate the generation of C 2+ products. Moreover, C 60 acts as an electron buffer, preventing Cu + from being over-reduced during the reduction process, thereby sustaining active Cu + /Cu 0 interfaces and maintaining the catalytic activity for C 2+ products. Extension to hydroxylated and fluorinated fullerene derivatives delivers comparable C 2+ selectivity, underscoring the generality of this fullerene-mediated stabilization strategy for designing robust Cu-based CO 2 RR catalysts.