文献类型：期刊文献

中文题名：SiO2改性钒钨钛催化剂的NH3-SCR反应性能

英文题名：Catalytic Activity of SiO2 Doped V2O5/WO3-TiO2 for Selective Catalytic Reduction of NOx by NH3

作者：王洪友[1];邵逊哲[1];王丽[1];詹望成[1];郭耘[1];卢冠忠[1]

机构：[1]华东理工大学工业催化研究所

年份：2018

卷号：42

期号：1

起止页码：53

中文期刊名：稀有金属

外文期刊名：Chinese Journal of Rare Metals

收录：CSTPCD;;EI(收录号：20182005188652);Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金：国家科技部863计划项目(2015AA034603);国家自然科学基金项目(21333003)资助

语种：中文

中文关键词：V2O5/WO3-TiO2;SiO2;NOx;NH3-SCR

外文关键词：V2Os/WO3-TiO2 ; SiO2 ; NOx ; NH3-SCR

摘要：柴油机以低油耗、高效率、动力强的优点，近年来得到了广泛的应用，但其尾气对城市环境的污染日益严重。NH3-SCR是目前处理柴油机尾气NO2最成熟的技术，V2O5／W03-TiO2催化剂因具有良好的NO3净化效率和优异的抗硫性能已得到商业应用，但低温活性和高温稳定性还有待提高。本文研究了Si02改性对V2O5／W03-Ti02催化剂（V205负载量为3％（质量分数））NH3-SCR反应性能的影响。评价结果表明，Si02改性催化剂在空速为60000h-1的条件下，低温区SCR反应性能有所下降，但是高温区SCR反应性能显著提高，催化剂表现出较宽的操作温度窗口，即NOx转化率在205～520 之间达80％以上。与V20，／W03-Ti02催化剂相比，温度窗口向高温拓宽了约50℃，并且经550℃老化50h后其活性基本保持不变。表征结果表明，SiO2改性显著增大了催化剂的比表面积，抑制了Ti02颗粒的增大，可稳定钨钛载体的结构，有利于钒和钨物种的分散；同时SiO2改性还增加了催化剂表面酸位点的数量和强度，并抑制NH3在高温氧化生成副产物。
The diesel engine has been widely used in recent years due to its high fuel economy and strong power. However, the diesel exhaust seriously pollutes the urban air. The selective catalytic reduction of NOx by ammonia （ NH3-SCR） was proved to be the most ef- ficient method to remove NOx in the diesel exhaust. Commercial V2Os/WO3-TiO2 catalyst was utilized commercially due to its high effi- ciency and excellent anti-sulfur performance, but its high temperature thermal stability and light-off activity still need to be improved. The effects of SiO2 on the catalytic activity of V2OJWO3-TiO2 with 3% VzO5 for NH3-SCR were investigated. The results showed that the doping of SiO2 slightly decreased the light-off activity, but increased the high-temperatures activity of V20JWO3-TiO2 significant- ly, and more than 80% NOx conversion was achieved in the temperature range of 205 - 520 ℃at a GHSV of 60000 h-l. Compared with V2Os/WO3-TiO2, the operation temperature window of SiO2 doped V2Os/WO3-TiO2 was broaden to higher temperature about 50 ℃. In addition, the NH3-SCR activity of SiO2 doped VzOJWO3-TiO2 could be maintained after calcinated at 550 ℃ for 50 h. The characterization results showed the doping SiO2 increased the surface area, inhibited the growth of TiO2 particles and stabilized WO3- TiO2 support, which resulted in a good dispersion of vanadium and tungsten species. Moreover, the presence of SiOx improved the a- mount of acid sites and acid strength, which were available for the NH3 adsorption and inhibited the oxidation of NH3 at high tempera- ture.