CeO_(2)对钒基催化剂NH_(3)-SCR反应性能的影响  

Effect of CeO_(2) on Performance of Vanadia-based Catalyst for Selective Catalytic Reduction of NO with NH_(3)

作　　者：蒋旻 邵迅哲 王丽[2] 韩玉峰 郭耘[2] Jiang Ming;Shao Xunzhe;Wang Li;Han Yufeng;Guo Yun(The 723 Institute of China Shipbuilding Industry Corporation,Yangzhou 225101,China;Research Institute of Industrial Catalysis,East China University of Science&Technology,Shanghai 200237,China)

机构地区：[1]中国船舶重工集团公司第七二三研究所,江苏扬州225101 [2]华东理工大学工业催化研究所,上海200237

出　　处：《中国稀土学报》2021年第5期750-758,共9页Journal of the Chinese Society of Rare Earths

基　　金：江苏省科技厅产业前瞻与共性关键技术开发应用项目(SBE2016000218)资助。

摘　　要：氮氧化物(NO_(x))是一种主要的大气污染物,采用氨选择性催化还原(NH_(3)-SCR)是实现NOx排放控制的最有效手段。以V_(2)O_(5)/TiO_(2)为研究对象,通过引入CeO_(2)对其结构及表面性质进行改性,显著提高了V_(2)O_(5)/TiO_(2)催化剂的NH_(3)-SCR反应性能,其中1%(质量分数)V_(2)O_(5)/Ce_(0.1)Ti_(0.9)O_(2)催化剂在180~470℃内NO_(x)的转化率在80%以上,具有较宽的温度操作窗口和良好的抗硫稳定性。表征结果表明:CeO_(2)的引入可抑制TiO_(2)晶体的长大,产生更多的结构畸变,并显著增大催化剂的比表面积。V和Ce物种之间的相互作用促进了催化剂表面V5+物种的形成,增强了催化剂对NO的吸附和氧化能力,并提供较多的弱和中等强度的酸性位,导致其低温SCR反应性能的显著升高;但同时表面强酸中心数量的减少以及NH_(3)非选择性氧化能力的升高,使其高温区SCR的活性明显降低。Nitrogen oxides(NO_(x)),as a main atmospheric pollutant,has caused fearful harm for human health and environment.The selective catalytic reduction of NO_(x) by ammonia(NH3-SCR)is the most effective technology for the removal of NO_(x).In this paper,the CeO_(2) was used to modify the structure and surface properties of V_(2)O_(5)/TiO_(2) catalyst,which promoted the SCR activity significantly.Among them,1% V_(2)O_(5)/Ce_(0.1)Ti_(0.9)O_(2) catalyst exhibited the best catalytic performance of NH3-SCR reaction and obtained more than 80% NO_(x) conversion in the temperature range of 180~470℃,it also showed the high sulfur resistance.The characterization results showed that the doped CeO_(2) blocked the growth of TiO_(2) crystallite and obviously increased the surface area.The synergy between V and Ce species promoted the formation of surface V5+species,enhanced the adsorption and oxidation of NO and provided more weak/medium acid sites,which improved the SCR activity in the low temperature range.However,the enhanced oxidation ability and reduced the strong surface acid sites decreased the SCR activities of V_(2)O_(5)/CexTi1-xO_(2) in the high temperature range.

关 键 词：V_(2)O_(5)/TiO_(2)催化剂 CeO_(2) 氮氧化物 NH_(3)-SCR 

分 类 号：TQ426[化学工程]