Highly Selective Electrocatalytic Reduction of CO₂ into Methane on Cu–Bi Nanoalloys
Zhijiang Wang, Qi Yuan, Jingjing Shan, Zhaohua Jiang, Ping Xu, Yongfeng Hu, Jigang Zhou, Lina Wu, Zhuangzhuang Niu, Jianmin Sun, Tao Cheng, William A. Goddard III
Abstract
Methane (CH₄), the main component of natural gas, is one of the most valuable products facilitating energy storage via electricity conversion. However, the poor selectivity and high overpotential for CH₄ formation with metallic Cu catalysts prevent realistic applications. Introducing a second element to tune the electronic state of Cu has been widely used as an effective method to improve catalytic performance, but achieving high selectivity and activity toward CH₄ remains challenging. Here, we successfully synthesized Cu–Bi NPs, which exhibit a CH₄ Faradaic efficiency (FE) as high as 70.6% at −1.2 V versus reversible hydrogen electrode (RHE). The FE of Cu–Bi NPs has increased by approximately 25-fold compared with that of Cu NPs. DFT calculations showed that alloying Cu with Bi significantly decreases the formation energy of *COH formation, the rate-determining step, which explains the improved performance. Further analysis showed that Cu that has been partially oxidized because of electron withdrawal by Bi is the most possible active site.
Group Members
Wang, Z., Yuan, Q., Shan, J., Jiang, Z., Xu, P., Hu, Y., Zhou, J., Wu, L., Niu, Z., Sun, J., Cheng, T., & III, W. A. G. (2020). Highly Selective Electrocatalytic Reduction of CO₂ into Methane on Cu–Bi Nanoalloys. *J. Phys. Chem. Lett.*, *11*(17), 7261-7266. https://doi.org/10.1021/acs.jpclett.0c01261