| 摘要 |
An alumino silicate zeolite "ZSM" type catalyst is mixed with a solution of a metal or metalloid compound e.g. magnesium acetate, the solution is concentrated and the mixture is dried and calcined to form a modified zeolite, e.g. with added MgO. …<??>Before or after this modification, the zeolite is treated by ion-exchange with a solution of Na<+>, K<+>, Rb<+> or Cs<+>, e.g. as a chloride, nitrate, bicarbonate, carbonate, phosphate, acetate or hydroxide, followed by filtration and washing, to give 0.5 - 1.0 atomic ratio of the ion per Al in the catalyst. …<??>The catalyst is used to dealkylate secondary and/or tertiary C3-12 alkyl groups in a 1,4-dialkylbenzene mixture, e.g. cymene, at 250 DEG to 600 DEG C, with high selectivity and good purity and yield of the recovered olefins. |
