Continuous CO₂ Capture and Selective Reduction to CO over Main-Group Dual-Functional Materials

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Dual-functional materials (DFMs) are key for carbon capture and utilization (CCU).
• Existing DFMs often rely on precious metals, limiting scalability and cost-effectiveness.
• Efficient CO2 capture and conversion to CO is crucial for sustainable chemical production.

Purpose of the Study:

• To develop a novel DFM composed solely of main-group elements for CO2 capture and reduction.
• To evaluate the performance of the developed DFM in terms of CO2 conversion and CO selectivity.
• To elucidate the reaction mechanism underlying the CO2 conversion process.

Main Methods:

• Synthesis of a cesium-impregnated alumina (Cs/Al2O3) DFM.
• High-temperature catalytic testing under isothermal conditions.
• Operando infrared spectroscopy, including modulation excitation spectroscopy, for mechanistic studies.

Main Results:

• Achieved high CO2 conversion (89%) and CO selectivity (99%) using the Cs/Al2O3 DFM.
• Demonstrated superior performance compared to platinum-group metal-based DFMs at 500 °C, even with oxygen present.
• Identified uniformly dispersed single Cs atoms on Al2O3 facilitating the reaction.
• Mechanistic studies revealed the reaction pathway involving adsorbed monodentate carbonate species.

Conclusions:

• Cs/Al2O3 represents a highly effective DFM for CO2 capture and selective CO production.
• The material's performance highlights the potential of main-group elements in advanced CCU applications.
• The findings provide valuable insights into the catalytic mechanisms for CO2 conversion.