Transformation of a Pt-CeO2 Mechanical Mixture of Pulsed-Laser-Ablated Nanoparticles to a Highly Active Catalyst for Carbon Monoxide Oxidation

摘要

The pulsed laser ablation (PLA) in alcohol and water media was employed to prepare Pt and CeO2 PLA-nanoparticles of different sizes and degrees of defectiveness. Interactions of metallic platinum and ceria particles were studied using the thermal activation of Pt-CeO2 mechanical mixtures in the CO+O-2 reaction medium or O-2 atmosphere. The thermal activation resulted in oxidized Pt2+/Pt4+ states of platinum in the surface solid solutions PtCeOx and/or PtOx clusters. Catalysts formed after calcination of the PLA-ablated Pt-CeO2 mixtures in oxygen at 450-600 degrees C revealed CO conversion at very low temperatures up to 70% depending on the conditions of PLA particles preparation and thermal activation of Pt-CeO2 mechanical mixture.