粉煤灰基介孔ZSM-5的孔径调控以及催化油烟中戊醛  

Aperture adjustment of mesoporous ZSM-5 based on fly ash for catalysis of pentanal in cooking fumes

作　　者：李建[1,2] 石应杰 付晓恒[1] 张凡[2] 黄家玉[2] 刘燕丽[3] 朱金伟 LI Jian;SHI Yingjie;FU Xiaoheng;ZHANG Fan;HUANG Jiayu;LIU Yanli;ZHU Jinwei(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Research Center of Air Pollution Control Technology,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Cangzhou Power Supply Co.Ltd.,State Grid Hebei Electric Power Supply Co.Ltd.,Cangzhou 061000,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]中国环境科学研究院大气污染控制研究中心,北京100012 [3]国网河北省电力有限公司沧州供电公司,河北沧州061000

出　　处：《中南大学学报（自然科学版）》2020年第5期1174-1188,共15页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2017YFC0212606,2017YFC0211503,2016YFC0204102);国家自然科学基金资助项目(51608500)。

摘　　要：利用粉煤灰中的硅铝组分并结合两段水热合成法制备介孔ZSM-5分子筛(HZ),通过控制介孔模板剂的添加量,得到一系列不同孔径的HZ分子筛。同时,对不同孔径的HZ分子筛进行水蒸气热处理研究,并采用XRD,SEM,TEM,27Al MAS-NMR和N2吸脱附实验等手段对HZ分子筛水蒸气热处理前后的物理化学性质进行表征。通过采用浸渍法制备质量分数为10%LaMnO3/HZ催化剂,对所有样品进行油烟中异味有机挥发物(戊醛和己醛)的催化氧化评价。研究结果表明:当PDADMAC与SiO2的质量比(m(PDADMAC):m(SiO2))小于0.30时,各分子筛均可保持一定的结晶度,其介孔容积可达0.24 cm^3/g,比表面积为302.1~428.5 m^2/g,平均孔径尺寸可达4.7 nm;分子筛的外观形貌随PDADMAC的增加由棒状组合成的微米级球状颗粒逐渐演变成纳米粒子的聚集体。水蒸气热处理后,各介孔ZSM-5分子筛均可以保持原来的MFI晶体结构且无脱铝现象发生,说明具有较强的水蒸气热稳定性,且催化效果均有所提高,而其平均孔径增加,晶粒尺寸变小。此外,负载LaMnO3之后,各分子筛均表现出较好的催化效果,其中具有适宜介孔结构的HZ-0.22更有利于催化。The mesoporous ZSM-5(HZ)zeolites with different pore sizes were synthesized via controlling the additive amount of polydiene dimethyl ammonium chloride(PDADMAC)using silicon aluminum components from the fly ash by the two-step hydrothermal treatment method.The hydrothermal stabilities of HZ zeolites were investigated,and the physicochemical properties were characterized by several techniques(XRD,SEM,TEM,27 Al MAS-NMR and N2 physical adsorption-desorption).The mass fraction of 10% LaMnO3/HZ catalysts were prepared by impregnation,and all the synthesized catalysts were investigated for the low-temperature catalytic oxidation of the odourous volatile organic compounds(pentanal and hexanal)in cooking fumes.The results show that the number of mesoporous structures of HZ zeolites increases as the mass ratio of PDADMAC to SiO2(m(PDADMAC):m(SiO2))increases.When m(PDADMAC):m(SiO2)is less than 0.30,all HZ zeolites can maintain a good crystallinity,the mesoporous volume can exceed 0.24 cm^3/g,the specific surface area is in the range of302.1-428.5 m^2/g and the average pore size exceeds 4.7 nm.Furthermore,the micron scale spherical particles composed of many bar-shaped nanocrystals are evolved into aggregations of nanoparticles with the increase of m(PDADMAC):m(SiO2).After steam heat treatment,all the HZ zeolites can maintain the MFI structure and do not dealuminate significantly,which reveals that they have good thermal stability of steam.However,the average pore size increases and the crystallite dimension decreases.Meanwhile,steam heat treatment can improve the catalytic oxidation level.Furthermore,10% LaMnO3/HZ has a good catalytic performance and the 10% LaMnO3/HZ-0.22,which has the suitable mesoporous structure,possesses the better catalytic activity and stability.

关 键 词：介孔ZSM-5分子筛 水热稳定性 油烟 催化氧化 LAMNO3 

分 类 号：X511[环境科学与工程—环境工程]