偶联剂共组装Ag@SiO_(2)-Co_(3)O_(4)催化剂高效乙烯催化脱除

Coupling agent co-assembly to Ag@SiO_(2)-Co_(3)O_(4)catalyst for efficient catalytic removal of ethylene

作为一种气体植物激素和大气污染物,微量乙烯的催化燃烧脱除法是最为经济有效的处理方式之一。以三维网状结构的Al-fiber(铝纤维片)作为骨架基体,借助水溶性硅烷偶联剂DEMSBA(4-二乙氧基甲基甲硅烷基丁胺)的双向桥联作用,即氨基与Ag纳米颗粒发生配位作用,以及乙氧基与Co(OH)_(2)表面羟基形成Co—O—Si键,实现整装式Ag@SiO_(2)-Co 3O 4/Al-fiber类核-壳结构催化剂的宏-微-纳一体化组装。通过优化制备参数如DEMSBA加入量、硅烷化反应时间和温度,整装式Ag@SiO_(2)-Co 3O 4/Al-fiber催化剂表现出良好的微量乙烯催化脱除活性和稳定性,在200℃、气时空速为10000 mL/(g·h)的条件下,连续反应120 h,乙烯转化率稳定在95%左右。

For the removal of plant hormone and atmospheric pollutant,catalytic combustion of ethylene(C_(2)H_(4))is one of the most economical and effective methods.Thin-sheets of Al-fiber with 3D network structure were employed as monolithic substrates.Monolithic Ag@SiO_(2)-Co_(3)O_(4)/Al-fiber catalyst with core-shell structure was prepared from nano-to macro-scale by the self-assembly method with the aid of the bidirectional bridging of water-soluble silane coupling agent DEMSBA(4-diethoxymethylsilyl-butanamine).The first bridging occurred between—NH_(2)and Ag nanoparticles by the preferential chelation,and the silanisation reaction between the ethoxy groups and surface OH groups on Co(OH)_(2)nanoarrays formed Co—O—Si bonds.By optimizing preparation parameters including the addition amount of DEMSBA,silanization reaction time and temperature,the gotten monolithic Ag@SiO_(2)-Co_(3)O_(4)/Al-fiber catalyst exhibits high catalytic combustion activity and stability for C_(2)H_(4)removal.C_(2)H_(4)conversion maintains at about 95%for 120 h running at 200℃and gas hourly space velocity of 10000 mL/(g·h).