TY - JOUR
T1 - Preparation of acid-base bifunctional MCM-22 zeolite by ultrasonic impregnation for Knoevenagel condensation
AU - Ren, Xiaoqian
AU - Wang, Junge
AU - Liang, Jinhua
AU - Zhang, Wenfei
AU - Jiang, Min
N1 - Publisher Copyright:
© 2014 Springer Science+Business Media.
PY - 2015/8/2
Y1 - 2015/8/2
N2 - The CaO/HMCM-22 catalysts were prepared by an ultrasonic impregnation method and their catalytic performances in Knoevenagel condensation were investigated. The characterization results of XRD, SEM, and TPD showed that no significant structural change of MCM-22 was observed after modification by CaO with ultrasonic assistance. Ultrasonic cavitation could reduce the agglomeration between particles and improve the dispersion of CaO on the surface. With the increase of CaO loading, the strength and content of base increased, and the strength of strong acid decreased, while the amount of weak acid sites increased slightly. The catalytic performance of CaO/HMCM-22 prepared by ultrasonic impregnation is better than that of CaO/NaMCM-22 and HMCM-22 for Knoevenagel condensation reactions, which indicates that the catalysts possess both acidic and basic sites after modification. Consequently, the acid-base bifunctional catalysts prepared by the ultrasonic impregnation method maintained high catalytic activity and have improved reusability. Compared with the conventional impregnation method, the strategy developed here is simple and efficient.
AB - The CaO/HMCM-22 catalysts were prepared by an ultrasonic impregnation method and their catalytic performances in Knoevenagel condensation were investigated. The characterization results of XRD, SEM, and TPD showed that no significant structural change of MCM-22 was observed after modification by CaO with ultrasonic assistance. Ultrasonic cavitation could reduce the agglomeration between particles and improve the dispersion of CaO on the surface. With the increase of CaO loading, the strength and content of base increased, and the strength of strong acid decreased, while the amount of weak acid sites increased slightly. The catalytic performance of CaO/HMCM-22 prepared by ultrasonic impregnation is better than that of CaO/NaMCM-22 and HMCM-22 for Knoevenagel condensation reactions, which indicates that the catalysts possess both acidic and basic sites after modification. Consequently, the acid-base bifunctional catalysts prepared by the ultrasonic impregnation method maintained high catalytic activity and have improved reusability. Compared with the conventional impregnation method, the strategy developed here is simple and efficient.
KW - Acid-base collaborative catalysis
KW - Knoevenagel condensation
KW - MCM-22 zeolite
KW - Ultrasonic impregnation
UR - http://www.scopus.com/inward/record.url?scp=84934440626&partnerID=8YFLogxK
U2 - 10.1007/s11164-014-1632-7
DO - 10.1007/s11164-014-1632-7
M3 - 文章
AN - SCOPUS:84934440626
SN - 0922-6168
VL - 41
SP - 5301
EP - 5310
JO - Research on Chemical Intermediates
JF - Research on Chemical Intermediates
IS - 8
ER -