Direct CO₂-to-CO conversion with H₂O on an In₂O₃ photocatalyst enabled by atomically precise Pd sites

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Indium oxide (In2O3) is a semiconductor material with potential applications in catalysis.
• Improving the efficiency and selectivity of carbon dioxide (CO2) reduction is crucial for sustainable energy solutions.
• Single-atom catalysis offers unique advantages in terms of atom utilization and catalytic activity.

Purpose of the Study:

• To develop a novel catalytic material for efficient CO2 reduction.
• To investigate the synergistic effects of palladium single atoms anchored on In2O3 nanotubes.
• To elucidate the reaction mechanisms and active sites for CO2 reduction and water oxidation.

Main Methods:

• Metal-Organic Framework (MOF)-templated synthesis of In2O3 nanotubes.
• Anchoring of palladium (Pd) single atoms onto the In2O3 nanotube structure.
• In situ X-ray Photoelectron Spectroscopy (XPS) for surface analysis.
• Density Functional Theory (DFT) calculations for mechanistic studies.

Main Results:

• Fabrication of Pd single-atom-anchored In2O3 nanotubes with lattice-confined Pd-O-In coordination.
• The engineered structure exhibited a narrowed bandgap and enhanced charge separation.
• Pd sites were identified as active for CO2 reduction, while In sites facilitated water oxidation.
• Achieved a 10-fold increase in carbon monoxide (CO) yield compared to pristine In2O3.

Conclusions:

• The MOF-templated strategy successfully created a highly efficient photocatalyst for CO2 reduction.
• The synergistic interaction between Pd single atoms and In2O3 nanotubes is key to the enhanced performance.
• This work provides insights into designing advanced single-atom catalysts for CO2 conversion.