CO₂ reduction to CH₄ on Cu-doped phosphorene: a first-principles study.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Optimizing electrochemical carbon dioxide reduction (CRR) to fuels is a critical challenge.
• Single atom catalysts on 2D materials show potential for improving CRR performance.
• The underlying mechanisms for these performance enhancements are not well understood.

Purpose of the Study:

• Investigate the potential of single copper (Cu) atom doped phosphorene as a catalyst for CO2 electroreduction.
• Determine the preferred doping site for Cu on phosphorene.
• Analyze the reaction pathways and identify the most likely products of CRR.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Investigated various Cu doping sites (hollow, bridge, on-top) on phosphorene.
• Constructed free energy diagrams to examine CRR pathways and compared limiting potentials.

Main Results:

• Cu atom anchored on the hollow site of phosphorene was found to be optimal.
• Methane (CH4) was identified as the most likely product of the CRR.
• Cu-doped phosphorene exhibited improved CRR performance with lower limiting potentials.
• Cu doping decreased the band gap of phosphorene by approximately 0.2 eV.

Conclusions:

• Single Cu atom doped phosphorene is a promising candidate catalyst for CO2 electroreduction.
• The reduction in band gap due to Cu doping is likely the physical origin of the enhanced CRR performance.
• This study offers a novel catalyst material for efficient CO2 conversion into fuels.