Acetone gas phase condensation on alkaline metals doped TiO2 sol–gel catalysts

Abstract The vapor-phase condensation of acetone was studied over sol–gel prepared TiO 2 and TiO 2 -doped with 1 wt.% of Li + or Rb + . The acetone condensation was catalyzed by basic sites and the obtained products were mesityl oxide (MO), isomesityl oxide (ISMO), mesitylene (M) as well as isophorone (IP) and phorone (P). The TiO 2 crystalline structure was characterized by XRD and the basicity of catalysts by means of CO 2 chemisorption. The number of basic sites was 0.057 mmol CO 2 /g for TiO 2 and Rb/TiO 2 and 0.676 mmol CO 2 /g for Li/TiO 2 catalyst. CO 2 -TPD showed that the strongest of the basic sites follows the order Rb/TiO 2 > TiO 2 > Li/TiO 2 . Activity was found of the same order in the three catalysts. Selectivity patterns shown that MO (70%) was the main product in Li/TiO 2 while for TiO 2 and Rb/TiO 2 comparable amounts of MO (41 and 44%) and M (39 and 39%) were obtained.