低钒高活性低温脱硝SCR催化剂:钒前驱体种类与表面钒浓度的影响  

Low-vanadium and high-activity SCR catalyst for low-temperature denitrification:Influence of vanadium precursor and surface vanadium concentration

作　　者：田茜 叶鹏 吴启龙 熊尚超 甘丽娜 陈建军[3] TIAN Xi;YE Peng;WU Qilong;XIONG Shangchao;GAN Lina;CHEN Jianjun(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Environment,Tsinghua University,Beijing 100084,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]西南交通大学地球科学与环境工程学院,四川成都610031 [3]清华大学环境学院,北京100084

出　　处：《燃料化学学报（中英文）》2024年第11期1696-1705,共10页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(22206130)资助。

摘　　要：本研究采用固相合成法制备了一系列不同钒前驱体和不同钒负载量的V_(2)O_(5)/TiO_(2)粉体催化剂。通过X射线衍射、X射线光电子能谱、氨气程序升温脱附和氢气程序升温还原等表征对催化剂的物理化学性质进行了分析,并在固定床反应器上对催化剂的脱硝活性进行了评价。以草酸氧钒(VOC_(2)O_(4)·xH_(2)O)和乙酰丙酮氧钒(VO(acac)_(2))为钒前驱体,钒负载量为5%时,制备的粉体催化剂在200-350℃条件下NO_(x)转化率稳定在100%,表现出最高的脱硝活性,相比于以偏钒酸铵(NH_(4)VO_(3))和硫酸氧钒(VOSO_(4)·H_(2)O)为钒前驱体制备的催化剂,其最高活性温度往低温区迁移了约150℃。而且以VO(acac)_(2)作为钒前驱体制备的低钒含量(1%)催化剂的脱硝活性甚至高于以NH_(4)VO_(3)为钒前驱体制备的高钒含量(6%)催化剂。结果表明,以VOC_(2)O_(4)和VO(acac)_(2)为钒前驱体能有效调控催化剂上的活性位点和聚合状态,促进不同价态的V原子相互作用,形成更多的还原性V物种(V^(4+)),从而表现出优异的SCR反应活性,同时也为制备低钒高活性的低温脱硝催化剂提供了一种有效方法。Nitrogen oxides(NO_(x)),as the main pollutants of air pollution,cause serious harm to the ecological environment and human health.SCR technology is widely used as the most effective method for treating NO_(x).The core of SCR technology is SCR catalyst.The reaction temperature of traditional commercial catalysts is difficult to reach the optimal operating temperature range,so expanding the temperature window of V_(2)O_(5)/TiO_(2) catalysts to the low-temperature region while reducing vanadium loading is a key issue to be solved.A series of V_(2)O_(5)/TiO_(2) catalysts with different vanadium precursors and different vanadium loadings were prepared by solid-phase synthesis method.The physicochemical properties of the catalyst were analyzed by X-ray diffraction,X-ray photoelectron spectroscopy,temperature programmed desorption of ammonia and temperature programmed reduction of hydrogen.The denitrification activity of the catalyst was evaluated in a fixed bed reactor.The catalysts prepared with vanadyl oxalate(VOC_(2)O_(4)·xH_(2)O)and vanadyl acetylacetonate(VO(acac)_(2))as vanadium precursors with a vanadium loading of 5%exhibited the highest denitrification activity,with a stable NO_(x) conversion of 100%within the temperature range of 200-350℃.Compared with the catalysts prepared with ammonium metavanadate(NH4VO3)and vanadyl sulfate(VOSO_(4)·xH_(2)O)as the vanadium precursors,the maximum activity temperature of VOC_(2)O_(4)-V5Ti and VO(acac)2-V5Ti shifted towards the low-temperature region by about 150℃.Furthermore,the denitrification activity of catalyst with a low vanadium content(1%)prepared using VO(acac)2 precursor was even higher than that of catalyst with a high vanadium content(6%)prepared using NH4VO3 precursor.Using VOC_(2)O_(4) and VO(acac)2 as vanadium precursors could effectively regulate the active sites and polymeric states on the catalysts,and promote the interaction of V atoms with different valence states to form more reductive V species(V^(4+)),thus exhibiting excellent SCR reactivity.This

关 键 词：SCR NO_(x) 钒基催化剂 前驱体 V_(2)O_(5)/TiO_(2) 

分 类 号：X511[环境科学与工程—环境工程]