In situ synthesized Cu-ZSM-5/cordierite for reduction of NO
来源期刊:中国有色金属学报(英文版)2011年第2期
论文作者:王建成 田东 韩丽娜 常丽萍 鲍卫仁
文章页码:353 - 358
关键词:原位合成;Cu-ZSM-5/堇青石;选择性催化还原;氨
Key words:in situ synthesis; Cu-ZSM-5/cordierite; selective catalytic reduction; NH3
摘 要:利用水热合成技术将ZSM-5分子筛直接合成到蜂窝状堇青石上。XRD、扫描电镜观察和超声波处理结果表明,ZSM-5和堇青石能够牢固结合,ZSM-5分子筛涂层质量和牢固度主要取决于晶化时间。采用离子交换或浸渍法制得Cu-ZSM-5/堇青石,利用模拟柴油机车尾气进行选择性催化还原NO。结果表明,在240?480 ℃的温度范围内,NO的转化率在90%以上,由离子交换或浸渍法制得的Cu-ZSM-5/堇青石都能在很宽的温度窗口(240?540 ℃)保持很高的脱硝转化率。
Abstract: ZSM-5 zeolites were directly synthesized on the surface of honeycomb cordierite substrates by hydrothermal method and certified by XRD and SEM techniques; the adhesion of ZSM-5 coatings was evaluated by ultrasonic vibration. Cu-ZSM-5/cordierite monolithic catalyst was prepared by ion-exchange and impregnation method and applied for the selective catalytic reduction (SCR) of NO by NH3 using a simulated diesel exhaust. The results show that the cordierite surface is almost completely covered by ZSM-5 crystals and the crystallization time greatly impacts the loadings and adhesion of ZSM-5 coatings on substrate, the NOx removal rate over Cu-ZSM-5/cordierite is above 90% in a temperature range of 240-480 ℃. Moreover, Cu-ZSM-5/cordierite prepared by different methods shows a wide temperature window (240-540 ℃) with high NO removal activities.