Supercritical Antisolvent Process to Produce Cerium Oxide Nanoparticles as a Support for High-Activity Platinum Catalysts

Abstract

Cerium acetylacetonate (Ce(acac)3) was precipitated from methanol (MeOH) using supercritical antisolvent process (SAS). The precursor was, then, calcined obtaining the cerium oxide (CeO2). Platinum (Pt) supported on cerium oxide is active for the water gas shift reaction, showing higher activity if compared with platinum supported on other oxides. The catalyst based on platinum supported on cerium oxide obtained using SAS process is more active than the Pt/CeO2 catalyst obtained in a conventional manner. The precursor nanoparticles were precipitated at different pressures and concentrations of the Ce(acac)3/MeOH solution. At the best operating conditions, nanoparticles with a diameter in the range 40-65 nm were obtained. The catalytic activity and the selectivity of two different samples was studied and compared. The catalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, infrared spectroscopy, nitrogen adsorption and desorption at 77 K, and mercury porosimetry.