Low temperature CO adsorption and oxidation over Au/rare earth-TiO2 nanocatalysts

Abstract

Titania supported nanogold (3-4 nm) catalyst exhibits remarkable activity for low temperature CO oxidation. Low melting point of gold nanoparticles may cause sintering of gold catalysts during their application at elevated temperatures which limit their use. It is reported that doping of the oxide support with rare earth (RE) ion helps in stabilization of gold metal particles due to change in the structural properties of the support. RE doped TiO2 supported Au catalysts have been investigated for CO adsorption by in situ Fourier transforms infrared spectroscopy and oxidation in a fixed bed reactor. It has been observed that RE doping significantly improves the catalytic activity of Au/TiO2 under ambient condition. Europium doping showed the highest effect on CO oxidation activity among different RE used in this study. It is suggested that doping of TiO2 with RE helps in stabilization of gold nanoparticles in Au/TiO2 during high temperature reaction. It provides additional adsorption/reaction sites for oxygen adsorption and interaction with adsorbed CO. (C) 2011 Elsevier B.V. All rights reserved.