铁修饰铝柱撑黏土催化剂(Fe/Al-PILC)的制备及其对C3H6-SCR活性的影响  

Influence of preparation process on C3H6-SCR activity over aluminum pillared clays modified with iron catalyst(Fe-Al-PILC)

作　　者：袁旻昊[1] 钱文燕 邓文义[1] 赵兵涛[2] 苏亚欣[1] YUAN Minhao;QIAN Wenyan;DENG Wenyi;ZHAO Bingtao;SU Yaxin(School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;School of Energy and Power Engineering,University of Shanghai Science and Technology,Shanghai 200093,China)

机构地区：[1]东华大学环境学院,上海201620 [2]上海理工大学能源动力学院,上海200093

出　　处：《环境工程学报》2020年第4期1022-1032,共11页Chinese Journal of Environmental Engineering

基　　金：上海市自然科学基金资助项目(19ZR1400700,17ZR1419300);中央高校基本科研业务费(2232019D3-24)。

摘　　要：制备了铝离子柱撑蒙脱土负载铁离子的催化剂,采用XRD、H2-TPR、Py-IR、UV-vis光谱、ICP、N2吸附-脱附等多种分析方法,对催化剂的基础物理化学性质进行了系统地表征。在固定床微反应器内,对丙烯在该催化剂表面选择性还原NO的特性进行了研究,考察了柱撑Al3+与黏土比例以及焙烧温度对催化剂的物化性质以及脱硝效果的影响。结果表明:9Fe/Al-PILC样品具有较高的C3H6-SCR脱硝性能,Al3+/蒙脱土的比值对脱硝性能的影响较大,而载体的焙烧温度的影响相对较小;按照Al3+/蒙脱土比值的大小,催化剂活性高低排序为9Fe/Al-PILC-10>9Fe/Al-PILC-20>9Fe/Al-PILC-5>9Fe/蒙脱土>9Fe/Al-PILC-40;柱撑离子Al3+使蒙脱土的比表面积急剧增大,催化剂具有微孔和介孔结构,Al3+/蒙脱土比为10 mmol·g-1时载体柱撑效果最佳;在负载铁离子后的Fe/Al-PILC催化剂中,铁氧化物高度分散在载体表面。H2-TPR表明催化剂的氧化还原性能可影响催化剂的SCR活性。UV-vis结果表明,低聚态FexOy物种的形成有助于提升催化剂的反应性能。Py-IR实验结果表明,Lewis酸和Br(?)nsted酸均有利于选择性催化还原NO,9Fe/Al-PILC-10催化剂活性最好,与其Bronsted酸含量较多有关。以上结果对于进一步优化柱撑黏土催化剂的合成工艺具有参考价值。Iron loaded aluminum-pillared montmorillonite catalysts(Fe-Al-PILC) were prepared.The analysis methods including XRD,H2-TPR,Py-IR,UV-vis,ICP,N2 adsorption-desorption,etc were used to systematically characterize the basic physical and chemical properties of the catalysts.In a fixed-bed reactor,the characteristics of NO selective catalytic reduction(SCR) by propylene on the catalyst surface were studied,and the effects of the Al3+/clay ratios and calcination temperature on the physicochemical properties and denitrification performance of the catalyst were investigated.The results showed that 9 Fe/Al-PILC had high C3H6-SCR performance,e.g.,100% NO conversion to N2 was tested at 400℃.The Al3+/clay ratio played more important role on NO conversion than the calcination temperature of the carrier.According to the Al3+/clay ratios,the order of catalytic activity was 9 Fe/Al-PILC-10>9 Fe/Al-PILC-20>9 Fe/Al-PILC-5>9 Fe/clay>9 Fe/AlPILC-40.Pillared Al3+ions dramatically elevated the specific surface area of the montmorillonite,and the catalyst had micropores and mesoporous structures.When the Al3+/clay ratio was 10 mmol·g-1,the pillared montmorillonite had the best physicochemical property.In the Fe/Al-PILC catalysts,the iron oxides were highly dispersed on the support.H2-TPR showed that the redox of the catalyst affected its SCR activity.UV-vis results showed that Al3+raised the amount of oligomer FexOy species,and the activity of the catalyst was positively correlated with the oligomer FexOy species.Py-IR results showed that both Lewis acid and Bronsted acid were conducive to the selective catalytic reduction of NO.9 Fe/Al-PILC-10 catalyst had the best SCR activity,which was related to its higher Bronsted acid content.The above results provide reference for further optimizing the preparation process of pillared clays catalyst.

关 键 词：选择性催化还原 柱撑黏土催化剂 丙烯 Al3+/蒙脱土 

分 类 号：X511[环境科学与工程—环境工程]