The Synthesis of ZrO2/SiO2 Nanocomposites by the Two‐Step CVD of a Volatile Halogen‐Free Zr Alkoxide in a Fluidized‐Bed Reactor

ZrO2/SiO2 nanocomposites with Zr loadings in the range 0.88 wt % to 12.2 wt % were prepared by a two‐step metal‐organic (MO)CVD process in a fluidized‐bed reactor with the Zr alkoxide [Zr(OiPr)2(tbaoac)2] as the precursor. The high surface area of silica was hardly diminished by the deposition, and the deposited zirconia species were highly dispersed, as indicated by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) investigations. The XPS data reveal a linear increase of the Zr surface concentration with increasing Zr loading. The high degree of dispersion is attributed to a strong interaction between the zirconia species and the support through the formation of Si‐O‐Zr bonds. Correspondingly, the intensity of the isolated silanol bands detected by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was found to decrease with increasing Zr loading.