Boron Phosphide Nanoparticles: A Nonmetal Catalyst for High-Selectivity Electrochemical Reduction of CO2 to CH3OH

Electrocatalysis has emerged as an attractive way for artificial CO2 fixation to CH3OH, but the design and development of metal-free electrocatalyst for highly selective CH3OH formation still remains a key challenge. Here, it is demonstrated that boron phosphide nanoparticles perform highly efficiently as a nonmetal electrocatalyst toward electrochemical reduction of CO2 to CH3OH with high selectivity. In 0.1 m KHCO3, this catalyst achieves a high Faradaic efficiency of 92.0% for CH3OH at -0.5 V versus reversible hydrogen electrode. Density functional theory calculations reveal that B and P synergistically promote the binding and activation of CO2, and the rate-determining step for the CO2 reduction reaction is dominated by *CO + *OH to *CO + *H2O process with free energy change of 1.36 eV. In addition, CO and CH2O products are difficultly generated on BP (111) surface, which is responsible for the high activity and selectivity of the CO2-to-CH3OH conversion process.