Electrochemical Fragmentation of Cu 2 O Nanoparticles Enhancing Selective C–C Coupling from CO 2 Reduction Reaction

In this study, we demonstrate that the initial morphology of nanoparticles can be transformed into small fragmented nanoparticles, which were densely contacted to each other, during electrochemical CO 2 reduction reaction (CO 2 RR). Cu-based nanoparticles were directly grown on a carbon support by using cysteamine immobilization agent, and the synthesized nanoparticle catalyst showed increasing activity during initial CO 2 RR, doubling Faradaic efficiency of C 2 H 4 production from 27% to 57.3%. The increased C 2 H 4 production activity was related to the morphological transformation over reaction time. Twenty nm cubic Cu 2 O crystalline particles gradually experienced in situ electrochemical fragmentation into 2–4 nm small particles under the negative potential, and the fragmentation was found to be initiated from the surface of the nanocrystal. Compared to Cu@CuO nanoparticle/C or bulk…