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基于脱铝多级孔BEA沸石与二氯二茂钛的固相反应,开展了钛掺杂量可调的多级孔Ti-beta后处理工艺制备研究.对制备的多级孔Ti-beta样品的理化性质进行了表征,包括X射线衍射、氮气吸附脱附测试、扫描电镜、透射电镜、紫外可见吸收光谱和紫外拉曼光谱等.结果表明,多级孔BEA沸石具有较好的化学稳定性,脱铝-钛化的后处理过程未对样品多级孔结构产生明显影响.以环己烯和十二烯的烯烃环氧化为探针反应表征了合成多级孔Ti-beta与纯相微孔Ti-beta沸石的催化性能.结果表明,在小分子环己烯的环氧化反应中,多级孔Ti-beta沸石的催化活性(转化率59.4%)与微孔Ti-beta相当(转化率57.9%);但是在较大分子十二烯的催化反应中,多级孔结构Ti-beta材料的催化性能(转化率11.1%)明显优于纯相微孔材料(转化率6.8%),且产物中环氧化物选择性更高(分别为60.3%和37.8%).
Based on the solid-state reaction of the dealuminated multi-stage BEA zeolite with titanocene dichloride, a multi-staged Ti-beta post-treatment process with adjustable titanium doping amount was developed. , Including X-ray diffraction, nitrogen adsorption and desorption test, scanning electron microscopy, transmission electron microscopy, UV-visible absorption spectrum and UV Raman spectroscopy.The results show that the multi-stage pore BEA zeolite has good chemical stability , And the dealumination-titanation did not affect the multi-level pore structure of the samples obviously.The epoxidation of cyclohexene and dodecene to probe was used to characterize the synthesis of multi-staged pore Ti-beta and pure phase The results showed that the catalytic activity (59.4% conversion) of multistage Ti-beta zeolite was similar to that of microporous Ti-beta in the epoxidation of small molecule cyclohexene Conversion rate of 57.9%). However, in the catalytic reaction of larger molecules of dodecene, the catalytic performance (conversion rate of 11.1%) of multi-stage pore structure Ti-beta material was significantly better than the pure phase microporous material (conversion 6.8% , And the epoxide selectivity was higher in the product (60.3% and 37.8%, respectively).