Preparation Of MWW Zeolite Catalysts And Their Application In The Acylation Of Anisole With Acetic Anhydride

As an important intermediate,p-methoxybenzophenone,has been widely used in fine chemicals and pharmaceuticals,which can be obtained by the Friedel-Crafts acylation of anisole with acetic anhydride.Zeolites have been proved good catalyst candidates,and MCM-22/MCM-49 zeolites with MWW topology show potential application ability in the acylation reaction.This dissertation focused on the alkali treatment modifications and catalytic application of MCM-22 and MCM-49 zeolites.Influence of alkaline treatment on the acidity and acylation activity of the corresponding catalysts were investigated in detail.In addition,the introduction of tetrapropylammonium hydroxide(TPAOH)into alkaline solution was also compared.A series of MCM-22 zeolites with different HMI contents were obtained by controlling the calcination temperature.After alkaline treatment,they were prepared for the alkylation reaction.It was found that the existence of HMI in zeolite channel was not beneficial for the anisole with acetic anhydride reaction.Compared with NaOH solution,introduction of TPAOH into NaOH solution was a good choice for the treatment of MCM-49 zeolites with certain content of HMI.Through changing the NaOH concentration,the best combination of TPAOH and NaOH was obtained.Among all the samples,C250-0.27TPA0.33 AT showed the highest acid density and the best acylation performance.Via the xylene disproportionation reaction and 2,4-dimethyl quinoline adsorption experiment,super cage and half super cage of HMCM-49 could be blocked.Influence of the channel contributions to acylation performance under different WHSV were investigated and elucidated.It was found that the acylation reaction mainly occurred on the half super cage of MCM-49 zeolite.Different WHSV showed little influence on the initial acylation reaction activity.