Sulfur-Decorated Ni-N-C Catalyst for Electrocatalytic CO₂ Reduction with Near 100 % CO Selectivity

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical CO2 reduction (ECR) is crucial for converting CO2 into valuable products.
• Developing highly efficient and stable electrocatalysts is key to advancing ECR technologies.

Purpose of the Study:

• To fabricate and investigate a sulfur-doped Ni-N-C catalyst for enhanced ECR to CO.
• To understand the synergistic effects of sulfur and Ni-Nx moieties on catalytic performance.

Main Methods:

• Fabrication of Ni-NS-C catalyst via ion-adsorption and pyrolysis.
• Electrochemical characterization of catalyst activity, selectivity, and stability.
• Density Functional Theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• The Ni-NS-C catalyst achieved a current density of 20.5 mA cm⁻² at -0.80 V vs. RHE.
• A maximum CO faradaic efficiency approaching 100% was obtained.
• The catalyst demonstrated excellent stability over 19 hours of operation.

Conclusions:

• Sulfur doping significantly enhances the activity and selectivity of Ni-N-C catalysts for ECR to CO.
• Synergistic effects between sulfur and Ni-Nx sites are responsible for the improved performance.
• This study offers insights for designing advanced M-N-C catalysts for CO2 conversion.