Study of strong metal-support interaction effect with pt-oxide model nanocatalysts

Abstract

Strong metal-support interaction effect is an important issue in determining the catalytic activity for het-erogeneous catalysis. In this study, we investigated the support effect of two-dimensional Pt nanocatalysts on reducible metal oxide supports under the CO Oxidation. Langmuir-Blodgett technique and Arc plasma deposi-tion process were employed to obtain Pt nanoparticle deposition on reducible metal oxide supports, which are $CeO_2$, $Nb_2O_5$, and $TiO_2$ thin films prepared via sol-gel techniques. The structure, chemical state and optical property were characterized using XRD, XPS, TEM, SEM, and UV-VIS spectrometer. From characterization, We can check that the reducible metal oxide supports have a homogeneous thin thickness and crystalline structure after annealing at high temperature with a different optical band gap energy. Colloidal Pt nanoparticles were deposited on reducible metal oxide thin films by Langmuir-Blodgett technique and APD Pt nanoparticles were deposited on the same conditioned thin films to assess the role of the supports on the catalytic activity of Pt catalysts under the CO Oxidation. We obtained the different catalytic activity for CO Oxidation reaction depending on the metal oxide support and process type for deposition of Pt nanoparticles. For metal oxide supports, the result shows that $CeO_2$ thin film has better performance as support under CO Oxidation over all types of Pt nanocatalysts, and on $Nb_2O_5$, on $TiO_2$, and $SiO_2$ in sequence. And for the colloidal Pt nanoparticles deposited on metal oxide thin films prepared by Langmuir-Blodgett technique, the activity is higher at all temperatures consistently than APD Pt deposited on metal oxide thin films prepared by arc plasma deposition process with different activation energies. The improvement of catalytic activity as a function of supports can bring the advanced application for catalysis.