Carbon-supported Ni nanoparticles for efficient CO₂ electroreduction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalysts are vital for converting carbon dioxide (CO2) into valuable products, addressing energy demands and environmental concerns.
• Developing selective, cost-effective, and energy-efficient electrocatalysts remains a significant challenge in CO2 electrocatalysis.
• Existing nickel-based catalysts often suffer from significant hydrogen evolution during CO2 reduction.

Purpose of the Study:

• To develop a highly selective and efficient electrocatalyst for the electroreduction of CO2 to CO.
• To investigate the role of carbon coating and nitrogen doping in enhancing catalyst performance.
• To compare the performance of the novel catalyst with existing state-of-the-art single Ni sites.

Main Methods:

• Synthesis of carbon-coated Ni nanoparticles supported on N-doped carbon.
• Electrochemical characterization, including CO2 electroreduction experiments.
• Density functional theory (DFT) calculations to elucidate the catalytic mechanism.

Main Results:

• The developed catalyst achieved an unprecedented CO faradaic efficiency of ~94% at an overpotential of 0.59 V.
• High CO partial current density (22.7 mA cm⁻²) and turnover frequency (697 h⁻¹) were observed.
• The carbon layer and N-dopants were found to stabilize the *COOH intermediate while facilitating *CO desorption.

Conclusions:

• Carbon-coated Ni nanoparticles on N-doped carbon represent a highly efficient electrocatalyst for CO2 to CO conversion.
• The synergistic effect of the carbon shell and N-doping is crucial for enhanced catalytic activity and selectivity.
• This catalyst offers a promising pathway for practical CO2 electroreduction applications.