Harmonizing the Electronic Structures of the Adsorbate and Catalysts for Efficient CO₂ Reduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Carbon dioxide (CO2) electroreduction is crucial for sustainable energy, but CO2 activation requires high overpotentials, hindering efficiency.
• Catalyst and adsorbate electronic structures critically influence CO2 activation, necessitating tailored catalyst design for optimal performance.

Purpose of the Study:

• To harmonize the electronic structures of adsorbates and manganese (Mn)-doped indium sulfide (In2S3) nanosheets for efficient CO2 electroreduction.
• To investigate the impact of Mn doping on the catalytic activity and electronic properties of In2S3 nanosheets for CO2 reduction.

Main Methods:

• Synthesis of Mn-doped In2S3 nanosheets.
• Electrochemical characterization including Faradaic efficiency (FE) and current density (j) measurements.
• Mechanistic studies involving analysis of electronic structure overlaps (p and d orbitals) during CO2 activation.

Main Results:

• Mn-doped In2S3 nanosheets demonstrated significantly enhanced FE for carbonaceous products and current density compared to pristine In2S3.
• At -0.9 V vs RHE, Mn-doped In2S3 achieved a 92% FE for carbonaceous products at a current density of 20.1 mA cm-2.
• Mechanistic studies revealed harmonic overlaps between O atoms' p orbitals and Mn atoms' d orbitals, lowering the CO2 activation energy barrier.

Conclusions:

• Harmonizing electronic structures via Mn doping in In2S3 nanosheets is an effective strategy for efficient CO2 electroreduction.
• The enhanced performance is attributed to optimized electronic interactions facilitating CO2 activation into formate (HCOO*).
• This work provides insights into catalyst design for improving CO2 electroreduction efficiency through electronic structure engineering.