Black indium oxide a photothermal CO₂ hydrogenation catalyst

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Stoichiometric indium oxide (In2O3) shows promise as a catalyst for CO2 hydrogenation.
• Current In2O3 catalysts are limited by poor light absorption, hindering combined thermal and light-driven reactions.
• Utilizing solar energy efficiently requires materials with enhanced optical properties.

Purpose of the Study:

• To develop a black indium oxide catalyst for improved CO2 hydrogenation.
• To investigate the relationship between non-stoichiometry and optical properties of In2O3.
• To enhance the catalytic performance for solar-driven CO2 conversion.

Main Methods:

• Synthesis of non-stoichiometric In2O3 by controlling oxygen vacancies.
• Characterization of the material's structure, color, and optical properties.
• Testing the catalytic activity and selectivity for CO2 hydrogenation.

Main Results:

• Achieved pitch-black In2O3 through controlled non-stoichiometry (In2O3-x).
• The black In2O3 catalyst exhibited 100% selectivity for CO2 hydrogenation to CO.
• A high turnover frequency of 2.44 s⁻¹ was recorded for the hydrogenation reaction.

Conclusions:

• Black, non-stoichiometric In2O3 is a highly effective catalyst for CO2 hydrogenation.
• This material enables efficient utilization of solar energy for CO2 conversion.
• The developed catalyst offers a promising pathway for sustainable chemical production.