Brazilian Journal of Physics
On-line version ISSN 1678-4448
FERREIRA, Hadma Sousa et al. A spectroscopic study of Au/CeXZr1-XO2 catalysts. Braz. J. Phys. [online]. 2009, vol.39, n.1a, pp. 141-145. ISSN 1678-4448. http://dx.doi.org/10.1590/S0103-97332009000200003.
The nature of gold species in Au/CeXZr1-XO2 catalysts was successfully investigated using the visible and near infrared photoacoustic spectroscopy and Fourier transform infrared spectroscopy of adsorbed carbon monoxide. It was found that the visible and near infrared photoacoustic spectroscopy is a powerful technique for investigating the changes of gold particle size due to addition of zirconium and the oxidation state of gold particles. It was also noted that the increase of zirconium in the solids makes gold incorporation more difficult due to the electronic shielding caused by zirconium, decreasing the probability of replacing cerium by gold. For the samples studied, the particle size ranged from 20-30 nm and the Au+, Au3+ and Auº species were found in the catalysts.
Keywords : gold catalysts; photoacoustic spectroscopy; CO adsorbed.