High-porosity Pt-CeO₂ nanosponges as oxidation catalyst

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Cerium oxide (CeO2) is a versatile material with applications in catalysis.
• Nanostructured materials offer enhanced surface area and reactivity for catalytic processes.
• Efficient catalytic oxidation of pollutants like CO, VOCs, and NH3 is crucial for environmental protection.

Purpose of the Study:

• To synthesize and characterize platinum-decorated cerium oxide nanosponges (Pt-CeO2).
• To evaluate the catalytic performance of Pt-CeO2 nanosponges for the oxidation of CO, VOCs, and NH3.
• To investigate the structural properties and thermal stability of the synthesized catalyst.

Main Methods:

• Synthesis of Pt-CeO2 nanosponges via thermal decomposition of cerium oxalate precursor followed by wet-chemical impregnation with platinum.
• Characterization using electron microscopy (with tomography), electron spectroscopy, thermogravimetric analysis (TG), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and sorption analysis.
• Evaluation of catalytic activity by monitoring light-out and light-off temperatures and selectivity for CO, VOCs, and NH3 oxidation.

Main Results:

• Pt-CeO2 nanosponges exhibited high surface area (113 m2 g-1), high pore volume (0.08 cm3 g-1), and small Pt nanoparticles (1.8 ± 0.4 nm).
• Optimal synthesis conditions for nanosponges were found at 350 °C for 20 min.
• The catalyst demonstrated good thermal stability up to 400 °C and promising catalytic activity for CO, VOCs, and NH3 oxidation, with high selectivity (>80%) to N2 for NH3 oxidation at 170-250 °C.

Conclusions:

• Pt-CeO2 nanosponges are effective catalysts for the oxidation of CO, VOCs, and NH3.
• The nanostructure and Pt nanoparticle distribution contribute to the observed catalytic performance.
• These materials hold potential for environmental applications requiring efficient pollutant degradation.