Pt-CeO₂ Catalysts Synthesized by Glucose Assisted Hydrothermal Method: Impact of Calcination Parameters on the Structural Properties and Catalytic Performance in PROX-CO.

Abstract

We synthesized Pt supported catalysts by the glucose assisted hydrothermal method, in which a carbon template was used to form a porous CeO2 structure upon calcination. Special emphasis was given to evaluate the influence of calcination parameters in the structural and textural properties of the catalysts and the final impact in the catalytic activity of CO oxidation reaction under hydrogen rich atmosphere (PROX-CO). We show that at 350 °C the carbon matrix was already mostly burnt and that higher temperatures and holding times mostly increase the CeO2 crystallite sizes. The sample prepared at 350 °C presented the highest surface area, 106 m2 ·g-1, in comparison to 60-70 m2 ·g-1 obtained for all other conditions. Transmission electron microscopy images of the catalyst calcined at 600 °C for 6 h showed 200 nm spheres formed by aggregation of ceria crystallites with crystalline domains of about 20 nm. All samples showed similar catalytic activity in PROX-CO indicating that the creation of the catalytic sites were mostly determined during the synthesis conditions and the catalytic performance were not deeply affected by the differences on CeOx matrix.