Multi-atomic loaded C₂N₁ catalysts for CO₂ reduction to CO or formic acid

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Electrochemical reduction of carbon dioxide (CO2) to valuable products like CO and formic acid is crucial for mitigating environmental pollution and greenhouse gas emissions.
• Atom-dispersed catalysts, particularly single-atom catalysts (SACs), are widely explored for CO2 reduction reactions (CO2RRs) due to their high atom utilization.
• Multi-atom catalysts offer enhanced catalytic performance over SACs due to more flexible active sites, unique electronic structures, and synergistic interatomic interactions.

Purpose of the Study:

• To establish and screen single-layer nitrogen-graphene supported transition metal catalysts (TM-C2N1) for CO2 reduction.
• To investigate the catalytic activity, stability, and selectivity of single-atom and multi-atomic TM-C2N1 catalysts for CO2RR.
• To elucidate the role of catalyst structure and electronic properties in determining product selectivity and reaction efficiency.

Main Methods:

• Density functional theory (DFT) calculations were employed to design and analyze the TM-C2N1 catalyst structures.
• Ab initio molecular dynamics, density of states, and charge density analyses were used to confirm catalyst stability and electronic properties.
• Gibbs free energy calculations and electronic structure analysis were performed to evaluate catalytic performance and limiting potentials.

Main Results:

• The stability of the TM-C2N1 catalyst structure was confirmed through systematic screening.
• 3TM-C2N1 catalysts demonstrated excellent performance for CO and HCOOH production in CO2RR with low limiting potentials.
• 3Mo-C2N1 achieved the best catalytic performance for CO production (UL = -0.62 V), while 3Ti-C2N1 excelled in HCOOH production (UL = -0.18 V), significantly inhibiting hydrogen evolution reactions.

Conclusions:

• The study highlights the significant potential of multi-atomic catalysts supported on nitrogen-graphene for efficient CO2 conversion.
• The d-band center plays a crucial role in determining the product selectivity and activity of triple-atom catalysts in CO2RR.
• This theoretical research provides new insights into multi-atomic catalysts and offers pathways for sustainable CO2 utilization.