- 作者: 柯安男 ; 張信川
- 作者服務機構: 東海大學化學系
- 中文摘要: The reaction of trimethylbenzene (TMB) over alumina-pillared montmorillonite (Al-PM) had been investigated in a fixed-bed flow reactor at 300.degree.C and atmospheric pressure. Al-PM calcined in the range 300-500.degree.C exhibited decreased layer distance, surface area and acid amount. The strong acid sites of Al-PM calcined at 500.degree.C were greatly diminished according to measurements of ammonia temperature-programmed desorption. Under our conditions the reaction proceeded mainly via isomerization and disproportionation with little dealkylation. The conversion of reactant decreased in the order 1,2,3-TMB.gtoreq.1,2,4-TMB>1,3,5-TMB and the selectivity of isomerization in the order 1,2,3-TMB>1,3,5-TMB>1,2,4-TMB, corresponding to the order of diminishing thermal instability. Both the catalytic activity and the selectivity ratio of disproportionation to isomerization decreased with increased calcined temperature and time-on-stream. 0-Xylene content in the total xylene produced from 1,2,4-TMB or 1,2,3-TMB greatly exceeded the composition at thermodynamic equilibrium. These results are consistent with the decrease of both the strong acid sites and the pore size of Al-PM which exhibits the restricted transition state selectivity.
- 英文摘要: --
- 中文關鍵字: Alumina Pillared Clay; Trimethylbenzene; Disproportionation; Isomerization; Catalyst; Acidity
- 英文關鍵字: 柱狀礬土;三甲基苯;不均化作用;異構化;觸媒;酸度