ZrO_2掺杂的V_2O_5/TiO_2催化剂表征及催化还原NO_x  

Characteriration of ZrO_2-doped V_2O_5/TiO_2 catalyst and its catalytic reduction of NO_x by NH_3

作　　者：朱孝强[1] 黄亚继[1] 沈凯[1] 徐海涛[1] 张亚平[1] 周长城[1] 

机构地区：[1]东南大学能源与环境学院，南京210096

出　　处：《环境化学》2012年第4期443-449,共7页Environmental Chemistry

基　　金：国家高级研究发展计划863项目(2007AA061802);江苏省攀登学者计划项目基金(BK2008001)资助

摘　　要：采用共沉淀法制备出不同锆掺杂量的钛锆复合载体(TiO2-ZrO2),运用XRD和BET研究其微观结构,结果显示钛锆物质的量之比1∶1时复合载体具有最大的比表面积,可达256.01 m.2g-1.以此为载体制备了V2O5/TiO2-ZrO2催化剂,并添加少量CeO2对其改性.采用XRD、BET、H2-TPR、原位FT-IR等手段研究其活性组分的表面分散状态、氧化还原特性和表面酸性.结果显示,V2O5高度分散在载体上;与纯V2O5相比,复合载体上V2O5的还原峰向低温方向发生了偏移;催化剂表面包含了大量的B酸和L酸.模拟氨气催化还原NO(NH3-SCR)的脱硝反应活性测试表明,V2O5/TiO2-ZrO2催化剂具有较好的热稳定性和较宽的活性窗口,少量CeO2的加入提高了催化剂的低温活性.TiO2-ZrO2 binary oxides with various compositions were synthesized by a co-precipitation method and were characterized by using X-ray diffraction and BET surface area technique.It was found that TiO2-ZrO2 composite（1 ∶ 1 molar ratio of Ti to Zr） had a high specific surface area（256.01 m2 · g-1）.Binary oxides V2O5 and V2O5-CeO2 supported on TiO2-ZrO2（1 ∶ 1 molar ratio） catalysts had been characterized by XRD,BET,H2-TPR,in situ FT-TR and acticity test for removal NO by NH3.The results showed that V2O5 was highly dispersed on the TiO2-ZrO2 support.H2-reduction peak of V2O5 supported on TiO2-ZrO2 was shifted to lower temperature compared with bulk V2O5 and there were significant amounts of Brnsted and Lewis acid sites.With a loading of CeO2,an obvious increase of surface acid sites and redox property was observed.The catalytic activity measurement indicated that the V2O5/ TiO2-ZrO2 sample exhibited excellent stability at high temperature and displayed better catalytic activity in a wide temperature range.The addition of CeO2 had evidently improved the NO conversion at low temperatures.

关 键 词：TiO2-ZrO2复合氧化物 CEO2 选择性催化还原 表面酸位 

分 类 号：X701[环境科学与工程—环境工程]