Synthesis of Titanium Silicon Composite Oxide Supported Cobalt Oxide Catalyst and Its Catalytic Performance for p-Diethylbenzene Oxidation.

TiO-SiO composite oxides with different Ti/Si ratios were synthesized by [sol-gel] method. The highest catalytic activity was obtained over T+S-0.75 loaded with 5 % CoO by in-situ method using cobalt stearate as precursor. XPS, XRD, SEM, TEM, N adsorption-desorption were used to characterize the state of titanium and cobalt species and the specific pore structure of catalyst. The characterization results combined with catalytic activity of p-Diethylbenzene (PDEB) oxidation show that the short-range mesoporous pore structure of T+S-0.75-C catalyst can facilitate the diffusion of large-volume reactants, intermediates and products. Meanwhile, the synergetic effect of Ti, Co and Co can promote the decomposition of HO and the generation of bromonium ions, which proceeds towards the target product during the reaction. Under the preferred reaction conditions, the oxidative conversion of PDEB in HO system is 31.1 %, and total selectivity of the target product reaches 85 %.