A Highly Active Star Decahedron Cu Nanocatalyst for Hydrocarbon Production at Low Overpotentials.

The electrochemical carbon dioxide reduction reaction (CO2 RR) presents a viable approach to recycle CO2 gas into low carbon fuels. Thus, the development of highly active catalysts at low overpotential is desired for this reaction. Herein, a high-yield synthesis of unique star decahedron Cu nanoparticles (SD-Cu NPs) electrocatalysts, displaying twin boundaries (TBs) and multiple stacking faults, which lead to low overpotentials for methane (CH4 ) and high efficiency for ethylene (C2 H4 ) production, is reported. Particularly, SD-Cu NPs show an onset potential for CH4 production lower by 0.149 V than commercial Cu NPs. More impressively, SD-Cu NPs demonstrate a faradaic efficiency of 52.43% ± 2.72% for C2 H4 production at -0.993 ± 0.0129 V. The results demonstrate that the surface stacking faults and twin defects increase CO binding energy, leading to the enhanced CO2 RR performance on SD-Cu NPs.