碱处理改性ZSM-5分子筛孔结构对VOCs吸附性能的影响
Effect of Pore Structure of Alkali Modified ZSM-5 Zeolite on Its VOCs Adsorption Performance
牛成 1赵洋 1钱程 1娄悦 1姜豪 1安阳 1沈本贤 2孙辉2
作者信息
- 1. 华东理工大学化工学院石油加工研究所,上海 200237
- 2. 华东理工大学化工学院石油加工研究所,上海 200237;华东理工大学绿色能源化工国际联合研究中心,上海 200237
- 折叠
摘要
采用氢氧化钠和四丙基氢氧化铵混合碱溶液处理制备一系列改性ZSM-5分子筛,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、N2吸附、水接触角测定等手段对改性样品进行了分析表征,采用固定床吸附器对比评价5A、NaY和不同碱改性ZSM-5分子筛吸附剂对正己烷和乙酸乙酯的动态吸附性能.结果表明:氢氧化钠和四丙基氢氧化铵摩尔浓度均为0.2 mol/L的碱改性ZSM-5-G-3样品的比表面积及总孔体积分别为425 m2/g和0.585 cm3/g,比改性前高硅ZSM-5-G-1样品分别提高了 17.7％和174.6％,介孔比表面积增加8.6倍,达到317 m2/g,介孔体积增加12.3倍,达到0.531 cm3/g;随着碱溶液浓度的增加,改性分子筛材料水接触角减小;25 ℃时,正己烷和乙酸乙酯在ZSM-5-G-3吸附剂床层上的穿透吸附量分别为76.99和101.08 mg/g,比改性前ZSM-5-G-1吸附剂床层分别提高了 40.3％和17.4％.改性ZSM-5-G-3样品对挥发性有机化合物(VOCs)吸附性能的显著提高主要归因于碱改性提供了更多的吸附位和介孔结构.
Abstract
A series of modified ZSM-5 zeolites were prepared via sodium hydroxide and tetrapropylammonium hydroxide mixed alkali solution.The modified samples were characterized by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),N2adsorption and water contact angle determination.Meanwhile,the dynamic adsorption performance of 5A,NaY,and different alkali-modified ZSM-5 zeolite adsorbents for n-hexane and ethyl acetate were comparatively evaluated on a customed fixed-bed adsorber.The results show that the alkali-modified ZSM-5-G-3 zeolite sample with the molar concentration of sodium hydroxide and tetrapropylammonium hydroxide of 0.2 mol/L have the specific surface area and pore volume of 425 m2/g and 0.585 cm3/g respectively,17.7％and 174.6％higher as compared with the parent samples of high-silicon ZSM-5-G-1 zeolite.In addition,the specific surface area and pore volume for ZSM-5-G-3 are observed as being 317 m2/g and 0.531 cm3/g,which are 9.6 and 13.3 times higher than those of ZSM-5-G-1,respectively.With an increase in the concentration of alkali solution,the water contacting angle of the modified zeolite decreases.At 25 ℃,n-hexane and ethyl acetate exhibit the breakthrough adsorption capacities of 76.99 mg/g and 101.08 mg/g in the fixed-bed adsorber filled with ZSM-5-G-3,indicating an increase of 40.3％and 17.4％compared to the parent adsorbent of ZSM-5-G-1.Furthermore,the significantly improved adsorption performance of the modified ZSM-5-G-3 zeolite for volatile organic compounds(VOCs)is mainly attributed to more adsorption sites and mesopore structures provided by alkali modification.
关键词
ZSM-5分子筛/碱改性/孔结构/吸附/挥发性有机化合物(VOCs)Key words
ZSM-5 zeolite/alkali modification/pore structure/adsorption/volatile organic compounds(VOCs)引用本文复制引用
基金项目
国家自然科学基金项目(21878097)
国家自然科学基金项目(22178109)
出版年
2024
NETL
NSTL
万方数据