Effect of the metal precursor on the properties of Pt/CeO2/C catalysts for the total oxidation of ethanol

Abstract

Two series of ceria-promoted carbon-supported platinum catalysts have been prepared and evaluated in total oxidation of ethanol, as a model volatile organic compound (VOC), in order to study the effect of the metal precursor (H2PtCl6 or Pt(NH3)4(NO3)2) on their physico-chemical properties and catalytic behavior. Catalysts with Pt loading of 1 wt.% and ceria loading of 5, 10 and 20 wt.% have been prepared by the impregnation method, and characterized by several techniques (N2 adsorption at 77 K, ICP, XRD, H2-TPR and XPS). Toluene hydrogenation has been used to obtain an estimation of the platinum dispersion on the investigated catalysts. On the other hand, their catalytic behavior has been evaluated in the total oxidation of ethanol, selected as a VOCs probe molecule. A much higher catalytic activity and selectivity to CO2 was achieved with chlorinated catalysts. This behavior has been correlated with a high platinum dispersion and a strong metal–CeO2 interaction in these catalysts which promotes their redox properties.