The low temperature (in situ) reduction of gold ions held on the surface of a suitable metal oxide support, by a strong reducing agent oxide facilitates the formation of embedded gold nanoparticles on that oxide support in such a fashion that, in comparison with other techniques, produces a more narrow size distribution and smaller particle size. Using titania as a the support, Raman spectra provide evidence for the modification of the TiO2 surface. The strongest E-g mode at 145 cm(-1), arising from the extension vibration of the anatase structure has been perturbed by the introduction of nanosized gold particles. The rate of oxidation of carbon monoxide in the present work for the Au-TiO2, corresponds to a turnover frequency of 0.1 s(-1) for reaction at 40degreesC based on a gold dispersion of 0.6 estimated on the basis of a mean particle size as determined by means of high-resolution transmission electron microscopy (HRTEM). (C) 2003 Elsevier B.V. All rights reserved.