Bismuth Anchored on MWCNTs with Controlled Ultrafine Nanosize Enables High-Efficient Electrochemical Reduction of Carbon Dioxide to Formate Fuel
Xia Zhang, Jing Fu, Yuyu Liu, Xiao‐Dong Zhou, Jinli Qiao
Abstract
Metal nanoparticles usually exhibit unique catalytic performance, while unfortunately, so far, the Bi nanoparticles (NPs) (<5 nm) have not been employed for the electrochemical reduction of carbon dioxide (ECR-CO2). Here, we report a facile and mild strategy to fabricate Bi nanocrystals in situ decorated on functionalized multiwalled carbon nanotubes (Bi NP@MWCNTs) as a high-performance catalyst for ECR-CO2. The transmission electron microscopy (TEM) images revealed that the Bi NPs with an average particle size of 4.4 nm were uniformly supported on the MWCNTs. The resulting Bi NP@MWCNTs exhibit much higher electrocatalytic activity, Faradaic efficiency (FE), and current density than the Biblank catalyst toward CO2 reduction to formate. At −1.5 V versus SCE (saturated calomel reference electrode), the maximum FE of 95.2% for formate was achieved on a Bi NP@MWCNT catalyst with a current density of 10.7 mA cm−2. MWCNTs play an important role in the markedly enhanced activity for CO2 reduction to formate on Bi NP@MWCNT catalysts. Besides, the formation of the *OCOH intermediate is considered as the rate-limiting step for CO2 conversion to formate on Bi NP@MWCNT catalysts. The results indicate that the as-prepared Bi NP@MWCNT catalysts exhibit promising potential in the electrochemical reduction of CO2 to fuels.