Gold-titania interactions: Temperature dependence of surface area and crystallinity of TiO2 and gold dispersion

The influence of temperature on the BET surface area, crystallinity, and anatase/rutile phase transformation of blank TiO2 and Au/TiO2 catalysts is studied. Presence of gold delays the recrystallization of anatase and the phase transformation into rutile. In turn, high gold dispersions are stabilized by TiO2 up to a temperature of 700 [deg]C. Agglomeration of gold into large particles coincides with the phase transformation into rutile at 800 [deg]C. The stability of the gold dispersion does not seem to be due to an SMSI effect. The low metal loading used to impregnate a high-surface-area TiO2 may be responsible for either an incorporation of gold atoms in interstitial positions of the TiO2 lattice, or the trapping of small gold particles in micropores.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24832/1/0000258.pd