A highly active Au/In₂O₃ catalyst for the reverse water gas shift reaction

Area of Science:

• Heterogeneous catalysis
• Nanomaterials science
• Green chemistry

Background:

• Supported gold catalysts are crucial for hydrogenation reactions.
• Gold nanoparticles exhibit unique electronic properties and catalytic activity.
• Indium oxide (In2O3) is a promising support material.

Purpose of the Study:

• To synthesize and evaluate a gold/indium oxide (Au/In2O3) catalyst for CO2 hydrogenation.
• To investigate the catalytic performance of Au/In2O3 in the reverse water gas shift (RWGS) reaction.
• To understand the structure-activity relationship and the role of metal-support interactions.

Main Methods:

• Deposition-precipitation method for Au nanoparticle synthesis.
• Characterization using various techniques to analyze catalyst structure and properties.
• Evaluation of catalytic activity under atmospheric pressure for CO2 hydrogenation.

Main Results:

• Au nanoparticles were uniformly dispersed on the In2O3 support.
• The Au/In2O3 catalyst demonstrated outstanding low-temperature activity for the RWGS reaction.
• Achieved 21.3% CO2 conversion, 100% CO selectivity, and a CO formation rate of 0.30 mmolCO gcat-1 min-1 at 350 °C.

Conclusions:

• The superior RWGS activity is attributed to strong electronic metal-support interaction (EMSI) between Au and In2O3.
• Positively charged Au species (Auδ+) facilitate H2 dissociation.
• Enhanced CO2 adsorption and activation due to surface oxygen vacancies on In2O3.