物理化学学报Issue(5)：965-972,8.DOI:10.3866/PKU.WHXB201503024
甘油脱水合成丙烯醛ZSM-5催化剂的孔结构和酸性调控
Regulation of Pore Structure and Acidity of a ZSM-5 Catalyst for Dehydration of Glycerol to Acrolein
摘要
Abstract
Pore structure and acidity of ZSM-5 catalysts were successful y regulated by alkali treatment. ZSM-5 was etched in 0.2 mol∙L-1 NaOH solution at 65 and 85 ° C. Micro-mesoporous ZSM-5 catalysts were successful y prepared with a high density of acidic sites. The activity and stability were significantly enhanced with alkali-treated ZSM-5, giving a conversion of glycerol above 95%, with selectivity for acrolein of 78%after 10 h compared with a ZSM-5-at85 (alkali-treated at 85 ° C) catalyst. Characterization of N2 adsorption and desorption isotherms, X-ray diffraction (XRD), 27Al mass atomic spectroscopy-nuclear magnetic resonance (27Al MAS-NMR), and transmission electron microscopy (TEM) were performed to interpret the morphology and surface properties. The results reveal that the Si in the framework of ZSM-5 was leached out by alkali treatment, and many mesopores were formed on the ZSM-5 surface. However, the MFI topology did not change and Al was mainly integrated within the framework. X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), and NH3-temperature-programed desorption (NH3-TPD) experiments demonstrated that the molar ratio of Si/Al on the external surface was lower than that in the framework, indicating that more Si on the external surface of ZSM-5 was leached by alkali treatment, while the acidic density increased because of the lower molar ratio of Si/Al near newly formed mesopores. ZSM-5 catalysts with mesopores and higher acidic density enhance reactant diffusion and coking tolerance, which improves the activity and stability during glycerol dehydration.关键词
微介孔ZSM-5/表面酸性/碱处理法/甘油脱水/丙烯醛Key words
Micro-mesoporous ZSM-5/Surface acidity/Alkali treatment/Dehydration of glycerol/Acrolein分类
化学化工引用本文复制引用
潘文雅,黄亮,秦枫,庄岩,李雪梅,马建学,沈伟,徐华龙..甘油脱水合成丙烯醛ZSM-5催化剂的孔结构和酸性调控[J].物理化学学报,2015,(5):965-972,8.基金项目
The project was supported by the Science and Technology Commission of Shanghai Municipality for International Collaboration Project, China (14120700700) and Funding of Key Laboratory, China (11JC1400400).上海市科学技术委员会资助国际合作项目(14120700700)和重点实验室基金(11JC1400400)资助 （14120700700）
