载铂多级孔ZSM-5分子筛用于邻二甲苯的“吸附?催化燃烧”循环脱除  

Pt Supported Hierarchical ZSM-5 Zeolite as Adsorbent/Catalytic Combustion Catalyst for o-xylene Elimination

作　　者：陈孟秋 王钰 杨登尧 邬红娟[1] 郭利民 CHEN Meng-Qiu;WANG Yu;YANG Deng-Yao;WU Hong-Juan;GUO Li-Min(School of Environmental Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学环境科学与工程学院,武汉430074

出　　处：《无机材料学报》2019年第2期173-178,共6页Journal of Inorganic Materials

基　　金：高性能陶瓷和超微结构国家重点实验室开放课题(SKL201707SIC);中国博士后科学基金(2016M602303)~~

摘　　要：首先利用F127作为软模板,采用蒸汽辅助晶化法合成出具有一定介孔结构的多级孔ZSM-5分子筛,然后采用等体积浸渍法负载铂,成功制备了载铂的多级孔ZSM-5分子筛催化剂。利用X射线衍射(XRD)、氮气吸附等温线(N2 isotherm)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对制备的催化剂进行了表征,并将催化剂用于邻二甲苯的吸附和催化燃烧反应,最后考察了催化剂"吸附-催化燃烧"循环脱除邻二甲苯的性能。结果表明,与传统ZSM-5分子筛相比,多级孔ZSM-5分子筛结晶度略有下降,但是介孔度和孔体积明显提升。介孔结构与微孔结构并存,极大提升了多级孔ZSM-5分子筛对邻二甲苯的吸附能力,其饱和吸附量达到了传统ZSM-5分子筛的约8倍。此外,介孔结构的存在提高了铂的分散度,使得载铂多级孔ZSM-5分子筛具有最佳的催化燃烧邻二甲苯性能,三次"吸附?催化燃烧"循环使用后的吸附容量依然基本保持不变,并且在催化燃烧过程中无二次污染物生成,具有较高的吸附容量和循环使用稳定性。Pt/hierarchical ZSM-5 zeolites were successfully synthesized by the steam-assisted crystallization and subsequent wetness impregnation method.Structural features were characterized by XRD,N2 isotherm,SEM,and TEM.Its catalytic behaviors for o-xylene storage at room temperature,and catalytic combustion of stored o-xylene at elevated temperatures were evaluated.It was found that crystallinity of the product underwent a reducing tendency after introduction of mesostructure,but the mesoporosity and pore volume were remarkably increased.Compared with Pt/conventional ZSM-5 zeolite,the o-xylene adsorption capacity of Pt/hierarchical HZSM-5 was around 8 times as that of the counterpart without mesostructure.Moreover,the Pt dispersion was improved due to mesoporosity.The highly dispersed Pt nanoparticles were beneficial for catalytic combustion of o-xylene.Futhermore,Pt/hierarchical ZSM-5 showed the efficient bi-functional performance during adsorption/catalytic combustion cycling process for o-xylene.Carbon balance was kept for three cycles without secondary pollutants,showing higher adsorption capacity and better reusing stability.

关 键 词：负载铂催化剂 多级孔分子筛 挥发性有机物 吸附 催化燃烧 

分 类 号：TQ174[化学工程—陶瓷工业]