Promotion of CO Electroreduction on Bismuth Nanosheets with Cerium Oxide nanoparticles.

Formic acid (HCOOH) is a highly energy efficient product of the electrochemical CO reduction reaction (CORR). Bismuth-based catalysts have shown promise in the conversion of CO to formic acid, but there is still a great need for further improvement in selectivity and activity. Herein, we report the preparation of Bi nanosheets decorated by cerium oxide nanoparticles (CeO) with high Ce/Ce ratio and rich oxygen vacancies. The CeO nanoparticles affect the electronic structures of bismuth, enhance CO adsorption, and thus promote the CORR properties of Bi nanosheets. Compared with elemental Bi nanosheets, the hetero-structured CeO/Bi nanosheets exhibit much higher activity over a wide potential window, showing a current density of 16.1 mA cm with a Faradaic efficiency of 91.1% at -0.9 V vs. reversible hydrogen electrode.