CAJ | 학술논문

采用酸碱复合改性的方法,制备了同时具有微孔和介孔孔道的丝光沸石,用于固定床 4-异丙基联苯的异丙基化反应.通过 X 射线衍射(XRD)、透射电子显微镜(TEM)、NH3 程序升温脱附(NH3-TPD)、N2 物理吸附脱附等方法对改性丝光沸石进行表征.结果表明,碱改性处理调变了丝光沸石的孔道结构和酸性质,同时保持了其MOR 拓扑结构,提高了 4-异丙基联苯的转化率和反应的稳定性.碱处理后再进行酸处理,可以有效清除碱处理过程中产生的非骨架铝物种和样品外表面的酸中心,提高目的产物 4,4'-二异丙基联苯的选择性.
채용산감복합개성적방법,제비료동시구유미공화개공공도적사광비석,용우고정상 4-이병기련분적이병기화반응.통과 X 사선연사(XRD)、투사전자현미경(TEM)、NH3 정서승온탈부(NH3-TPD)、N2 물리흡부탈부등방법대개성사광비석진행표정.결과표명,감개성처리조변료사광비석적공도결구화산성질,동시보지료기MOR 탁복결구,제고료 4-이병기련분적전화솔화반응적은정성.감처리후재진행산처리,가이유효청제감처리과정중산생적비골가려물충화양품외표면적산중심,제고목적산물 4,4'-이이병기련분적선택성.
Isopropylation of 4-isopropybiphenyl to 4,4'-diisopropylbiphenyl was carried out over hierarchical mesoporousmordenite zeolites through alkalis modification of H-mordenite zeolite in a fixed-bed reactor. In order to investigate the effects of the pore structure and the acid sites of the zeolite samples on the catalytic properties, the parent and modified zeolite samples were thoroughly characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), ammonia temperature programmed desorption (NH3-TPD), and N2 physical adsorption-desorption. The results showed that the alkalis treatment adapted the pore structure, and the acid strength and amount without obvious destruction to the MOR topological structure. This adaption was contributed to the improvements of 4-isopropybiphenyl conversion and reaction stability. Modifying the sample with alkalis first and then followed by an acid treatment was in favor of removing the extra-framework alumina from the alkalis treatment and adapting the acid sites on the extra surface of the sample, which can successfully improve the selectivity of 4,4'-diisopropylbiphenyl.