Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibite...Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibited typical hexagonal structure,large surface areas and narrow pore distribution.The performance of HAl-MCM-41 as catalyst for tert-butylation of p-cresol with methyl tert-butyl-ether（MTBE） was then investigated.The effects of temperature,weight hourly space velocity（WHSV） and the feed ratio n（MTBE）/n（p-cresol） on p-cresol conversion and product selectivity were examined.The results showed that mesoporous HAl-MCM-41 molecular sieves（n（SiO2）/n（Al2O3） = 20） is an efficient catalyst with high activity,selectivity and stability for the synthesis of 2-tert-butyl-p-cresol from p-cresol and MTBE by tert-butylation.展开更多
A series of Cr-containing MCM-41 molecular sieves crystallized at room temperature with a hexagonal and well-ordered structure were synthesized. XRD, FT-IR and DRS UV-Vis techniques were used to characterize the sampl...A series of Cr-containing MCM-41 molecular sieves crystallized at room temperature with a hexagonal and well-ordered structure were synthesized. XRD, FT-IR and DRS UV-Vis techniques were used to characterize the samples. The results indicate incorporation of Cr into the MCM-41 framework, and dispersion of some CrsO3 on the surface or/and in the bulk of the MCM-41. Test of catalytic properties of the series of samples for the topic reaction was carried out using a continuous-flow fixed-bed quartz reactor. Factors influencing the catalytic performance for this title reaction, such as Cr/Si ratio in MCM- 41 and reaction temperature were investigated. The experimental results indicate that over the 5%CrMCM-41 a 43.27% conversion of ethane and a 86.70% selectivity for ethylene were achieved in the ethane dehydrogenation with COs to ethylene at 973 K. It is suggested that both Cr^6＋ and Cr^3＋ are the catalytic activity center.展开更多
文摘Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibited typical hexagonal structure,large surface areas and narrow pore distribution.The performance of HAl-MCM-41 as catalyst for tert-butylation of p-cresol with methyl tert-butyl-ether（MTBE） was then investigated.The effects of temperature,weight hourly space velocity（WHSV） and the feed ratio n（MTBE）/n（p-cresol） on p-cresol conversion and product selectivity were examined.The results showed that mesoporous HAl-MCM-41 molecular sieves（n（SiO2）/n（Al2O3） = 20） is an efficient catalyst with high activity,selectivity and stability for the synthesis of 2-tert-butyl-p-cresol from p-cresol and MTBE by tert-butylation.
基金This work was financially supported by the Sci—ence and Technology Department of Jilin Province，China(20040703—2)and the sub·Program of the Sci—ence and Technology Cooperation Project between China and Spain．
文摘A series of Cr-containing MCM-41 molecular sieves crystallized at room temperature with a hexagonal and well-ordered structure were synthesized. XRD, FT-IR and DRS UV-Vis techniques were used to characterize the samples. The results indicate incorporation of Cr into the MCM-41 framework, and dispersion of some CrsO3 on the surface or/and in the bulk of the MCM-41. Test of catalytic properties of the series of samples for the topic reaction was carried out using a continuous-flow fixed-bed quartz reactor. Factors influencing the catalytic performance for this title reaction, such as Cr/Si ratio in MCM- 41 and reaction temperature were investigated. The experimental results indicate that over the 5%CrMCM-41 a 43.27% conversion of ethane and a 86.70% selectivity for ethylene were achieved in the ethane dehydrogenation with COs to ethylene at 973 K. It is suggested that both Cr^6＋ and Cr^3＋ are the catalytic activity center.
