摘要
通过在细小Y型沸石晶粒表面嫁接介孔分子筛的途径，对Y型沸石表面进行改性。采用X射线衍射、透射电子显微镜、低温N2吸附、NH3程序升温脱附和吡啶吸附红外光谱方法对改性样品进行了表征，并详细考察了其在苯酚叔丁基化反应中的催化性能。结果表明，优化合成条件，使Y沸石晶粒均匀地分布于介孔分子筛的孔壁之中，形成核壳／包覆结构，对沸石表面的酸性能起到调节作用，在苯酚转化率90％以上时，叔丁基苯酚的选择性达到100％。
Micro-/mesoporous composite Y/MCM was successfully synthesized by grafting mesoporous material on the surface of nano-Y zeolite. The Y/MCM composites with different micro-/mesoporous component ratios were characterized by powder X-ray diffraction, transmission electron microscopy and N2 adsorption-desorption methods. The results showed the micro-and mesoporous properties of Y/MCM and its core-shell enwrapped structure. NHa temperature-programmed desorption and in-situ pyridine adsorbed infrared spectra results indicated medium and strong acid sites and the distribution of Bronsted and Lewis acid sites on the Y/MCM surface. The number of acid sites and the ratio of Bronsted to Lewis acid sites can be adjusted by changing the ratio of micro-/mesoporous component in the Y/MCM composite. During the alkylation of phenol with tert-butanol, the Y/MCM catalyst displayed higher conversion of phenol and selectivity for tert-butyl phenol than the single microporous Y or mesoporous MCM-41 catalyst. At the reaction temperature of 180℃, a high phenol conversion of 92% and tert- butyl phenol selectivity of 100% over Y/MCM are observed. The mesoporous size （2--3 nm） in the Y/MCM is beneficial to the effective diffusion of reactants and productsl obvious catalyst deactivation of Y/MCM is not observed even after reaction for 6 h. And Y/MCM can be very well recycled in the tert-butylation of phenol.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2008年第B10期213-218,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
中国石化科学基金项目（107009）资助
