摘要
采用共沉淀法制备Ge-Mn共改性TiO_(2)载体,考察了V-Mo-O/Ge-x Mn-TiO_(2)催化剂的低温氨选择性催化还原(NH_(3)-SCR)活性和抗硫稳定性。Ge-Mn的加入可显著提高催化剂在低温窗口下的脱硝活性,且具有较高的N2选择性和抗硫稳定性。当Ge:Mn:Ti的原子摩尔比为0.004:0.04:1,在140℃时脱硝活性为92%。催化剂的N2吸附-脱附、NH_(3)-TPD、H_(2)-TPR、XRD和XPS分析结果表明:Mn加入使催化剂的介孔增加,表面总酸性位和中高强度酸性位量显著增加,从而增加了催化剂对NH_(3)的吸附活化和对SO_(2)吸附的抑制;Mn与V、Mo、Ge活性组分发生了强电子相互作用,使V^(5+)含量增加,且使低温活性组分的氧化还原循环易于进行,进而增加了催化剂的低温脱硝活性。这说明增加的表面总酸性位和中高强度酸性位量、增加的V^(5+)和由此形成的低温条件促进了活性组分氧化还原循环,最终提高了催化剂的低温活性和高抗硫稳定性。本研究可为低温脱硝催化剂的研发及应用提供参考。
Ge-Mn co-modified TiO_(2)support was prepared by co-precipitation method,and the activity and sulfur resistance of low-temperature ammonia selective catalytic reduction(NH_(3)-SCR)and sulfur resistance of V-Mo-O/Ge-xMn-TiO_(2)catalysts were investigated.Compared with traditional V-Mo-O/TiO_(2)catalysts,the addition of Ge-Mn significantly improved the denitrification activity of the catalyst at low temperature window,and at the same time had high N2selectivity and stable sulfur resistance.When the Ge:Mn:Ti atomic molar ratio was 0.004:0.04:1,the denitrification activity could reach 92%at 140℃.The N2adsorption-desorption,NH_(3)-TPD,H_(2)-TPR,XRD and XPS analysis results of the catalyst showed that the addition of Mn increased the mesoporosity of the catalyst,meanwhile the total surface acid sites and the amount of medium and high strength acid sites increased significantly,which increased the catalyst’s adsorption activation of NH_(3)and inhibition of SO_(2)adsorption.Mn interacted with the active components of V,Mo,and Ge,which increased the content of V^(5+)and facilitated the redox cycle of the active components at low temperature,thus the low-temperature denitration activity of the catalyst was increased.Therefore,the increase of total surface acid sites,mediumstrength acid sites,high-strength acid sites,and V^(5+)content and the formation of a low-temperature facile redox cycle of active components improved the catalyst’s low-temperature activity and high sulfur resistance stability.
作者
张鑫丰
李泽清
陈红萍
ZHANG Xinfeng;LI Zeqing;CHEN Hongping(College of Chemical Engineering,North China University of Science and Technology,Tangshan 063009,China;Hebei Key Laboratory for Environment Photocatalytic and Electeocatalytic Materials,Tangshan 063009,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第1期156-164,共9页
Chinese Journal of Environmental Engineering
基金
河北省自然科学基金资助项目(B2017209111)
河北省高等学校科学技术研究项目(ZD2015116)。
关键词
共改性
低温
SCR
载体
催化剂
Co-modification
low temperature
SCR
carrier
catalyst
