1. Operando studies reveal active Cu nanograins for CO2 electroreduction
- Author
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Yang, Yao, Louisia, Sheena, Yu, Sunmoon, Jin, Jianbo, Roh, Inwhan, Chen, Chubai, Fonseca Guzman, Maria V, Feijóo, Julian, Chen, Peng-Cheng, Wang, Hongsen, Pollock, Christopher J, Huang, Xin, Shao, Yu-Tsun, Wang, Cheng, Muller, David A, Abruña, Héctor D, and Yang, Peidong
- Subjects
Engineering ,Materials Engineering ,Chemical Sciences ,Affordable and Clean Energy ,CSD-02-CAT-A ,CSD-46-All CSGB ,General Science & Technology - Abstract
Carbon dioxide electroreduction facilitates the sustainable synthesis of fuels and chemicals1. Although Cu enables CO2-to-multicarbon product (C2+) conversion, the nature of the active sites under operating conditions remains elusive2. Importantly, identifying active sites of high-performance Cu nanocatalysts necessitates nanoscale, time-resolved operando techniques3-5. Here, we present a comprehensive investigation of the structural dynamics during the life cycle of Cu nanocatalysts. A 7 nm Cu nanoparticle ensemble evolves into metallic Cu nanograins during electrolysis before complete oxidation to single-crystal Cu2O nanocubes following post-electrolysis air exposure. Operando analytical and four-dimensional electrochemical liquid-cell scanning transmission electron microscopy shows the presence of metallic Cu nanograins under CO2 reduction conditions. Correlated high-energy-resolution time-resolved X-ray spectroscopy suggests that metallic Cu, rich in nanograin boundaries, supports undercoordinated active sites for C-C coupling. Quantitative structure-activity correlation shows that a higher fraction of metallic Cu nanograins leads to higher C2+ selectivity. A 7 nm Cu nanoparticle ensemble, with a unity fraction of active Cu nanograins, exhibits sixfold higher C2+ selectivity than the 18 nm counterpart with one-third of active Cu nanograins. The correlation of multimodal operando techniques serves as a powerful platform to advance our fundamental understanding of the complex structural evolution of nanocatalysts under electrochemical conditions.
- Published
- 2023