Unveiling Asymmetric Dual-Metal Interfaces for Solar-Driven CO₂-to-CH₄ Reduction Coupled with C-H Activation.

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Solar-driven conversion of CO2 and biomass-derived alcohols is crucial for mitigating CO2 emissions and producing chemicals.
• Challenges include complex reaction pathways and slow C-H bond activation for efficient CO2 reduction to CH4 and alcohol valorization.

Purpose of the Study:

• To develop an efficient photocatalytic system for tandem CO2 reduction to CH4 and C-H oxidation of biomass-derived alcohols.
• To design asymmetric dual-metal catalytic centers by anchoring semiconductor nanoclusters in vacancy-rich metal-organic frameworks (MOFs).

Main Methods:

• Loading Fe2O3 nanoclusters into O-vacancy-rich Mil-125(Ti)-NH2 MOFs to create interfacial O-vacancies and asymmetric Ti-Fe dual-metal sites.
• Utilizing Z-scheme electron transfer pathways facilitated by Fe-O bonds for photocatalysis.
• Investigating reaction mechanisms through experimental and computational methods.

Main Results:

• Achieved a superior selectivity of 87.0% for CH4 production from CO2.
• Demonstrated 100% selectivity for benzyl alcohol to benzaldehyde oxidation.
• Identified synergistic effects of Ti-Fe dual-metal sites in facilitating CO2 hydrogenation and C-H bond oxidation.

Conclusions:

• The asymmetric dual-metal interface design enables efficient and selective tandem CO2 photomethanation and C-H activation.
• This approach provides a general strategy for creating advanced MOF-based photocatalysts for simultaneous CO2 conversion and biomass valorization.