Optimizing Materials to Boost the Valorization of CO₂: Tuning Cobalt-Cobalt Interactions on In₂O₃-Based Photothermal...

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Carbon dioxide (CO2) is a major greenhouse gas, necessitating effective valorization strategies.
• Developing efficient catalysts for CO2 conversion is crucial for mitigating climate change.
• Nanostructured materials offer unique properties for catalytic applications.

Purpose of the Study:

• To synthesize and characterize cobalt-doped indium oxide nanostructures for CO2 valorization.
• To investigate the effect of cobalt loading on the catalytic activity and properties.
• To establish a structure-activity relationship for optimizing photothermal CO2 conversion.

Main Methods:

• Synthesis of nanostructured batonnet-type indium oxide with varying cobalt (Co) content (2-8% mol).
• Physical and chemical characterization using X-ray absorption spectroscopy and other techniques.
• Evaluation of catalytic activity for CO2 to carbon monoxide (CO) transformation under thermal and dual photothermal excitation.

Main Results:

• The catalyst with 6% mol Co exhibited the highest activity in CO2 to CO transformation.
• Dual photothermal excitation enhanced catalytic activity by over 30% compared to thermal methods.
• Catalysts with ≤4% Co featured isolated single-atom cobalt species, while higher loadings showed Co-Co interactions influencing performance.

Conclusions:

• Optimized Co-Co interactions and cobalt species nature are key for dual photothermal catalytic properties.
• A structure-activity relationship was established for highly dispersed subnanometric cobalt species.
• This research provides a pathway for enhancing the photothermal valorization of CO2.