Simply and effectively electrodepositing Bi-MWCNT-COOH composite on Cu electrode for efficient electrocatalytic CO2 reduction to produce HCOOH

Electrocatalytic CO2 reduction to produce low-carbon chemicals/fuels is one of the most important approaches for CO2 emissions reduction and utilization. However, the insufficient catalytic activity, stability and selectivity of the electrocatalysts have been identified to be a major challenge. In this work, novel Bi-MWCNT-COOH/Cu catalysts are prepared via a facile co-electrodeposition technique on copper foil to obtain catalyst electrodes for selectively electro-catalyzing CO2 reduction to produce formic acid (HCOOH). The as-prepared electrodes exhibited high catalytic activity, stability and selectivity toward the production of HCOOH. The faradaic efficiency for HCOOH production can reach values up to 91.7 % at -0.76 V vs. RHE, with no obvious degradation after 12 h of continuous electrolysis. The proposed electrodeposition technique to produce composite catalyst electrodes is characterized by simplicity, rapidity, and cost-effectiveness, being promising for scaled-up industrial applications.