Bera, Parthasarathi and Patil, KC and Jayaram, V and Subbanna, GN and Hegde, MS (2000) Ionic Dispersion of Pt and Pd on CeO2 by Combustion Method: Effect of Metal-Ceria Interaction on Catalytic Activities for NO Reduction and CO and Hydrocarbon Oxidation. In: Journal of Catalysis, 196 (02). pp. 293-301.
PDF
sdarticle.pdf4.pdf - Published Version Restricted to Registered users only Download (220kB) | Request a copy |
Abstract
Ceria-supported Pt and Pd catalysts have been synthesized by the combustion method. The catalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Pt and Pd metals are ionically dispersed on the CeO2 surface of crystallite sizes in the range of 15-20 nm. In 1% Pt/CeO2 Pt is found to be in the +2 and +4 oxidation states whereas Pd is in the +2 state in 1% Pd/CeO2. Catalytic activities for NO reduction by CO, NH3, CH4, and C3H8 and CO, CH4, and C3H8 oxidation by O-2 have been investigated over all these catalysts using the temperature-programmed reaction technique. The results are compared with Pt and Pd metals dispersed on alpha -Al2O3 support prepared by the combustion technique. Both oxidation and reduction reactions occur at much lower temperatures over M/CeO2 compared to those over M/Al2O3 (M = Pt, Pd). The rate and turnover frequency of NO + CO and CO + O-2 reactions over M/CeO2 are higher than those over M/Al2O3. The observed enhanced catalytic activity of M/CeO2 has been attributed to the ionic dispersion of Pt and Pd on CeO2 leading to a strong metal-ceria interaction in the form of solid solution, Ce1-xMxO2-(4-n)x/2, having linkages of the type -O2--Ce4+-O2--Mn+-O2--(n=2, 4) on the CeO2 surface
Item Type: | Journal Article |
---|---|
Publication: | Journal of Catalysis |
Publisher: | Elsevier Science |
Additional Information: | Copyright of this article belongs to Elsevier Science. |
Keywords: | combustion synthesis; metal-ceria interaction;Pt/CeO2;P/CeO2;NO;CO;hydrocarbon. |
Department/Centre: | Division of Chemical Sciences > Solid State & Structural Chemistry Unit |
Date Deposited: | 27 Aug 2009 04:30 |
Last Modified: | 19 Sep 2010 04:59 |
URI: | http://eprints.iisc.ac.in/id/eprint/17962 |
Actions (login required)
View Item |