Boosting selective CO₂ reduction via strong spin-spin coupling on dual-atom spin-catalysts

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis
• Computational Chemistry

Background:

• Electrochemical conversion of carbon dioxide (CO2) into valuable products is crucial for sustainability but faces selectivity challenges.
• Dual-atom catalysts (DASCs) in two-dimensional metal-organic frameworks (2D-MOFs) and zero-dimensional molecular metal complexes (0D-MMCs) show promise for CO2 reduction reactions (CO2RR).
• The influence of catalyst spin states on CO2RR selectivity is not fully understood.

Purpose of the Study:

• To investigate the impact of spin states on the selectivity of DASCs in 2D-MOFs and 0D-MMCs for CO2 electroreduction.
• To establish a correlation between spin-spin coupling and selective CO2 reduction product formation.
• To provide a strategy for designing tunable and efficient electrocatalysts for CO2 conversion.

Main Methods:

• First-principles calculations were employed to systematically evaluate DASCs (TM2S4(NH)2(C6H4)2 0D-MMC and TM2S4(NH)2C4 2D-MOF) across antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic (NM) spin states.
• Analysis focused on CO2 reduction reactions (CO2RR) and product selectivity.
• Machine learning was utilized to identify key electronic and geometric descriptors influencing catalytic performance.

Main Results:

• Catalyst selectivity for C1 products in CO2 reduction can be effectively tuned by adjusting the spin states of DASCs through spin-spin coupling.
• Mn2 and Fe2 2D-MOF DASCs in an AFM ground state preferentially produce formic acid.
• FM counterparts of Mn2 and Fe2 2D-MOF DASCs favor methane formation over formic acid; 0D-MMCs exhibit comparable performance to their 2D-MOF counterparts.

Conclusions:

• Spin-spin coupling in DASCs is a critical factor for achieving high selectivity in CO2 electroreduction.
• The study demonstrates a direct link between catalyst spin state and the preferential formation of specific CO2 reduction products (formic acid vs. methane).
• This work offers a viable approach for designing advanced electrocatalysts with tunable selectivity for CO2 conversion applications.