The defect engineering and S-bridged d-p-p orbital hybridization synergistically enhance CO₂ electroreduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nickel-based catalysts show promise for CO2 electroreduction to CO.
• Intrinsic electronic structure and defects hinder high catalytic performance.

Purpose of the Study:

• To design novel sulfur-bridged nickel/carbon catalysts with defects (Ni-S1@CVC) for enhanced CO2 electroreduction.
• To investigate the role of sulfur doping and carbon defects in catalyst performance.

Main Methods:

• Density Functional Theory (DFT) calculations to study electronic structure and electron transport.
• Synthesis and characterization of Ni-S1@CVC catalysts.
• Electrochemical testing of CO2 reduction to CO.

Main Results:

• Sulfur incorporation formed d-p-p hybrid orbitals and shifted Ni 3d orbital energy towards the Fermi level.
• Carbon defects regulated electron distribution, activating Ni-S-C electron transport channels.
• Ni-S1@CVC achieved 98% Faradaic efficiency for CO and a 34-fold increase in partial current density compared to Ni@CVC.

Conclusions:

• Sulfur bridging and carbon vacancies facilitate rapid electron transfer for enhanced CO2 electroreduction.
• The study provides insights into electron transport in sulfur-bridged transition metal/carbon catalysts.
• This work offers new strategies for designing efficient electrocatalysts for CO2 conversion.