MoS₂ Grain Boundary-Supported Single-Atom Catalysts for Efficient Electrocatalytic CO₂ Conversion to CO

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• High-efficiency single-atom catalysts (SACs) are crucial for the carbon dioxide reduction reaction (CO2RR).
• Achieving optimal performance in CO2RR catalysts remains a significant challenge.
• Grain boundary (GB) engineering offers a novel approach to catalyst design.

Purpose of the Study:

• To design and investigate molybdenum disulfide (MoS2) supported SACs utilizing a GB strategy for electrocatalytic CO2RR.
• To explore the impact of anchoring different 3d transition metal (TM) atoms at various MoS2 GBs on CO2RR activity.
• To establish a structure-activity relationship for TM@GB SACs in CO2RR.

Main Methods:

• Density-functional theory (DFT) calculations were employed to model and analyze TM@GB SACs.
• Various 3d transition metals were anchored at three types of MoS2 GBs (5|7, 8|8, and 4|8).
• Electrocatalytic performance was evaluated by calculating the overpotential for CO2 reduction to CO.

Main Results:

• Strong interactions between TM atoms and MoS2 GBs were found to enhance CO2RR activity by shifting the d-band center.
• V@5|7, Cr@8|8, and V@4|8 GB SACs exhibited excellent catalytic activity for CO2 reduction to CO at low potentials (-0.30, -0.10, and -0.26 V vs SHE, respectively).
• A new descriptor (ψ) correlating GB and TM structural properties with CO2RR activity was proposed.

Conclusions:

• GB engineering is a viable strategy for modulating the properties of SACs for improved CO2RR.
• The developed TM@GB SACs show significant potential for efficient electrocatalytic CO2 conversion.
• This work provides insights into catalyst design and optimization for CO2 utilization.