VPO/TiO_(2)催化剂表面酸性位调控及低温NH_(3)-SCR脱硝性能研究  

The optimization of surface acidity VPO/TiO_(2)catalyst and its low-temperature NH_(3)-SCR denitration performance

作　　者：陈宜华[1] 王攀 孟凡禹 陈雅芬 张铭 贾勇[1] CHEN Yi-hua;WANG Pan;MENG Fan-yu;CHEN Ya-fen;ZHANG Ming;JIA Yong(Department of Environmental Science and Engineering,Anhui University of Technology,Maanshan 243002,China)

机构地区：[1]安徽工业大学环境科学与工程系,安徽马鞍山243002

出　　处：《中国环境科学》2023年第4期1558-1566,共9页China Environmental Science

基　　金：国家重点研发计划项目(2017YFB0601805)。

摘　　要：采用HCl调控负载型钒磷氧(VPO/TiO_(2))催化剂的表面酸性,用于研究VPO/TiO_(2)催化剂的NH_(3)-SCR脱硝性能.结果表明:在HCl/V物质的量比为3~5:1范围内,催化剂的脱硝活性最高,当反应温度达到200℃时脱硝效率接近100%.表征结果表明:HCl的添加能提高催化剂的结晶度,HCl的调控使得VPO/TiO_(2)催化剂的比表面积略有增加.同时,也使得VPO/TiO_(2)催化剂中活性组分V^(4+)的量从38%逐渐升高至46%,提高了催化剂的氧化还原性能.此外,不同HCl/V物质的量比的催化剂中化学吸附氧的相对含量随着HCl加入量的增加而提高.吡啶红外测试结果显示:HCl能影响催化剂酸性位点,HCl/V物质的量比=5的催化剂Lewis酸含量最高,总酸量为0.84×10^(-4)mol/g.数据拟合进一步表明,所有VPO/TiO_(2)催化剂的低温脱硝活性均与弱Lewis酸量呈正相关(相关系数>0.9),与活性测试相吻合.HCl was used to modify the surface acidity of supported vanadium phosphorus oxide(VPO/TiO_(2))catalysts for NH_(3)-SCR.The results show that the denitration activity of catalyst was the highest with HCl/V molar ratio of 3~5:1,and the efficiency was almost 100%when the reaction temperature reached 200.It was found that the addition o℃f HCl improved the crystallinity of the catalyst,and the modification of HCl could slightly increase the specific surface area of the VPO/TiO_(2)catalyst.Meanwhile,the amount of active component V^(4+)in the VPO/TiO_(2)catalyst was gradually increased from 38%to 46%,which improved the redox performance of the catalyst.In addition,the relative content of chemisorbed oxygen in the catalysts with different HCl/V molar ratios increased with the increase of HCl addition amount.The pyridine infrared test results show that HCl affected the acid site of the catalyst,and the catalyst with HCl/V molar ratio=5 had the highest Lewis acid content as 0.84×10^(-4)mol/g.Data fitting results further demonstrate that the low-temperature denitration activities of all VPO/TiO_(2)catalysts were positively correlated with the amount of weak Lewis acid(correlation coefficient>0.9),which is consistent with the results of activity test.

关 键 词：VPO/TiO_(2)催化剂 低温NH3-SCR 脱硝 表面酸性 调控 

分 类 号：X701[环境科学与工程—环境工程]