Oxygen Storage Capacity and CO Oxidation Performance of CeO₂ Nano-Octahedra with Saturated In³⁺ Doping

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Cerium dioxide (CeO₂) is a key catalyst due to its redox properties and oxygen storage capacity (OSC).
• However, its low-temperature catalytic activity is a significant limitation.
• Indium (In³⁺) doping is explored to enhance CeO₂ properties.

Purpose of the Study:

• To investigate the impact of saturated In³⁺ doping (1 mol.%) on nano-octahedral CeO₂.
• To evaluate the effects on structural, redox, and catalytic characteristics.
• To understand the mechanism behind enhanced low-temperature CO oxidation.

Main Methods:

• Synthesis of In³⁺-doped nano-octahedral CeO₂.
• Structural and chemical characterization (e.g., XRD, XPS).
• Redox property evaluation (H₂-TPR, OSC analysis).
• Catalytic performance testing (CO-TPSR, FTIR).

Main Results:

• In³⁺ doping induced lattice contraction and increased oxygen vacancy concentration (29.7% to 39.8%).
• Surface Ce³⁺ fraction increased, enhancing reducibility (lower reduction temperatures).
• Significant improvements in low-temperature OSC and CO oxidation activity (lower light-off temperatures).

Conclusions:

• Saturated In³⁺ doping effectively enhances oxygen vacancy concentration and surface reducibility of nano-octahedral CeO₂.
• Doping significantly improves low-temperature CO oxidation performance.
• Surface hydroxyl groups play a role in the enhanced catalytic mechanism.