Highly efficient electrocatalytic CO₂-to-ethanol conversion over bimetallic CuPd catalysts via selective CC coupling

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Heteroatom doping of copper catalysts enhances CO$_{2}$ electroreduction to C$_{2+}$ products.
• Electrocatalytic reduction of CO$_{2}$ to ethanol suffers from low selectivity and Faradaic efficiency.

Purpose of the Study:

• To develop a highly selective and efficient catalyst for electrocatalytic reduction of CO$_{2}$ to ethanol.
• To investigate the effect of palladium (Pd) doping on copper (Cu) nanoparticles (NPs) for improved ethanol production.

Main Methods:

• A simple one-pot synthesis method was employed to prepare bimetallic CuPd$_{x}$ catalysts.
• Electrochemical performance was evaluated using a flow-cell setup.
• Density Functional Theory (DFT) calculations were used to elucidate reaction mechanisms.

Main Results:

• The CuPd$_{0.1}$ catalyst achieved a high C$_{2+}$ Faradaic efficiency of 72.5%.
• Specifically, it demonstrated a Faradaic efficiency of 63.0% for CO$_{2}$ electroreduction to ethanol.
• A high partial current density of 335 mA·cm$^{-2}$ for ethanol was achieved at 1.16 V (vs. RHE).

Conclusions:

• Palladium doping in Cu NPs optimizes active sites, enhances CO$_{2}$ adsorption via oxygen vacancies, and lowers the energy barrier for CC coupling.
• The synergistic effects of Pd doping steer the reaction pathway towards ethanol production, significantly improving selectivity and catalytic activity.
• The developed CuPd$_{0.1}$ catalyst shows great promise for efficient electrocatalytic conversion of CO$_{2}$ to ethanol.