Synergistic effect between In₂O₃ and ZrO₂ in the reverse water gas shift reaction.

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Efficient carbon dioxide (CO2) utilization is crucial for mitigating climate change.
• Developing effective catalysts for CO2 conversion reactions, such as the reverse water gas shift (RWGS) reaction, is an active area of research.
• Low-temperature CO2 activation remains a significant challenge in catalysis.

Purpose of the Study:

• To investigate the interface effect between In2O3 and ZrO2 for efficient CO2 activation.
• To develop a novel catalyst for the reverse water gas shift (RWGS) reaction.
• To elucidate the reaction mechanism involving formate intermediates.

Main Methods:

• Synthesis of In2O3-ZrO2 mixed oxides with varying molar ratios.
• Catalytic testing of the synthesized materials in the RWGS reaction under specific conditions (400 °C, 0.1 MPa, H2:CO2 = 3:1, GHSV = 10,000 mL g-1 h-1).
• In situ Fourier-transform infrared (FTIR) spectroscopy to study reaction intermediates.

Main Results:

• The 75In2O3-25ZrO2 catalyst (3:1 molar ratio) exhibited excellent performance.
• Achieved 28% CO2 conversion with 96% CO selectivity at 400 °C.
• In situ FTIR confirmed the pivotal role of formate species at the In2O3-ZrO2 interface.

Conclusions:

• The interface effect between In2O3 and ZrO2, driven by geometric and electronic factors, enables efficient low-temperature CO2 activation.
• The developed In2O3-ZrO2 catalyst is highly effective for the RWGS reaction.
• Formate intermediates play a key role in the catalytic mechanism at the catalyst interface.