无模板法合成的Phi分子筛在NO选择性催化还原中的应用  

Phi zeolite synthesized by template-free method for selective catalytic reduction of NO

作　　者：杨润农 余林[1] 赵向云 杨晓波 高梓寒 傅广赢 姜久兴 练纬琳 刘武源 范群 YANG Runnong;YU Lin;ZHAO Xiangyun;YANG Xiaobo;GAO Zihan;FU Guangying;JIANG Jiuxing;LIAN Weilin;LIU Wuyuan;FAN Qun(Guangzhou Key Laboratory of Clean Transportation Energy Chemistry,School of Chemical Engineering and Light Industry,Guangdong University of Technology,Guangzhou 510006,Guangdong,China;Waygreen Environmental Protection Technology Co.,Ltd.,Guangzhou 511441,Guangdong,China;School of Chemistry,Sun Yat-Sen University,Guangzhou 510275,Guangdong,China)

机构地区：[1]广东工业大学轻工化工学院,广州市清洁交通能源化学重点实验室,广东广州510006 [2]广州市威格林环保科技有限公司,广东广州511441 [3]中山大学化学学院,广东广州510275

出　　处：《化工学报》2020年第12期5578-5588,共11页CIESC Journal

基　　金：国家自然科学基金项目(21576054);广东省省级科技计划项目(2016B020241003)。

摘　　要：氮氧化物(NOx)是大气中的一种主要污染物。采用具有菱沸石结构(CHA)的铜基分子筛作为催化剂,通过选择性催化还原(SCR)技术可有效去除NOx。采用一种经济环保的制备方法,在不使用模板剂的条件下水热合成一种具有结构缺陷的低硅铝比CHA型分子筛(Phi,Si/Al=4.7)。结果表明,经Cu离子交换制备的Cu/Phi具有最丰富的表面酸性与孤立态Cu^2+,表现出较好的低温活性、较宽的工作温度窗口以及良好的水热稳定性。Na或Mg的存在降低了Cu/Phi的表面酸性及孤立态Cu^2+的含量,水热老化后的Na,Cu/Phi和Mg,Cu/Phi均呈现出不同程度的骨架坍塌,相应导致了催化剂失活。Nitrogen oxide(NOx)is one of the major air pollutants.Using a copper-based zeolite with a chabazite structure(CHA)as a catalyst,the selective catalytic reduction(SCR)technology can effectively remove NOx.This work introduces a low silica CHA type zeolite with structural defects(zeolite Phi,with Si/Al of 4.7).The zeolite Phi is synthesized through a hydrothermal method without adding any template,which is low-cost and environmentfriendly.The Cu-exchanged Phi is abundant of surface acidity and isolated Cu^2+,showing a superior lowtemperature activity,a wide work temperature window and a good hydrothermal stability.The presence of Na or Mg decreases the surface acidity and isolated Cu^2+.The hydrothermally aged Na,Cu/Phi and Mg,Cu/Phi present different levels of framework collapse,which correspondingly induces catalyst deactivation.

关 键 词：分子筛 催化剂 碱/碱土金属离子 水热稳定性 失活 NH3-SCR 

分 类 号：TQ032[化学工程]