Green catalytic oxidation of ethylbenzene to acetophenone over modified TS-1 zeolite supported cobalt oxide

The development of catalysts and processes with high activity, good selectivity and easy reproducibility and regeneration is the core of the solution for the oxidation of ethylbenzene to acetophenone. In this paper, the catalyst of cobalt metal oxide supported on TS-1 zeolite co-modified by alkali treatment and titanium silicon composite oxide was prepared. The catalysts were characterized by XRD, Raman, N₂ adsorption-desorption, SEM, TEM, XPS, FT-IR and UV–vis techniques to establish the correlation between physical and chemical properties and catalytic performance. Among the prepared catalysts, SiO₂ and TiO₂ co-coated TS-1 supported 3.75 wt % Co₃O₄ catalyst showed better oxidation activity. Under the optimized reaction conditions: T = 80 °C, t = 8 h, m_cat = 0.03 g, nEB: nHAC: nKBr: nH₂O₂ = 1 : 21: 0.1 : 16, the conversion of ethylbenzene was as high as 86.7 % and the selectivity of acetophenone was 85.6 %. After repeated tests, it showed good cycle and regeneration reaction performance. The high activity of this catalyst is attributed to the synergistic effect of cobalt oxide and TS-1 zeolite, and the mesoporous structure of titanium-silicon composite oxide is conducive to the adsorption and diffusion of reactants, intermediates and products.