Influence of ignition atmosphere on the structural properties of magnetic iron oxides synthesized via solution combustion and the NH3-SCR activity of W/Fe2O3 catalyst

作     者：Li, Cheng-xu Xiong, Zhi-bo He, Jun-fei Qu, Xiao-ke Li, Zhen-zhuang Ning, Xing Lu, Wei Wu, Shui-mu Tan, Lu-zhi 

作者机构：Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China SPIC Powder Plant Operat Technol Beijing Co Ltd Beijing 102209 Peoples R China Ludong Univ Sch Food Engn Yantai 264000 Peoples R China 

出 版 物：《APPLIED CATALYSIS A-GENERAL》 (应用催化，A辑：总论)

年 卷 期：2020年第602卷

页      面：117726-117726页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：National Science Foundation of China Program of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning [QD2015017] 

主　　题：De-nitrogen Selective catalytic reduction Magnetic iron oxide Tungsten doping Solution combustion Ignition atmosphere 

摘      要：Two kinds of magnetic iron oxides (Fe2O3-PO and Fe2O3-AO) are synthesized via the solution combustion coupled with the chemical oxidization of hydrogen peroxide. The magnetic carbon-containing Fe2O3-AO obtained at the absence of air presents the main gamma-Fe2O3 crystal with smaller crystallite size and larger BET surface area, but not the aggregated and sintered alpha-Fe2O3 crystal of Fe2O3-PO. The doping of tungsten has no effect on the growth of alpha-Fe(2)O(3)in Fe2O3-PO during the annealing process at 400 degrees C. However, the doping of tungsten effectively restrains the irreversible transformation of gamma-Fe2O3 into alpha-Fe2O3 crystal and enhances the anti-collapse of the pore structure of Fe2O3-AO under the same annealing process at 400 degrees C by inducing a stronger interaction between tungsten species and gamma-Fe2O3 crystal. In addition, the doping of tungsten improves the ratio of surface adsorbed oxygen, the Fe2+/(Fe2++Fe3+) ratio and the surface acidity of Fe2O3-PO-400 and Fe2O3-AO-400. Therefore, the doping of tungsten promotes the catalytic performance of Fe2O3-PO-400, especially its high-temperature activity, but exhibits a better promotional effect on the low-temperature activity of Fe2O3-AO400. Magnetic 5W/Fe2O3-AO-400 shows the highest BET surface area, the largest Fe2+/(Fe2++Fe3+) ratio, the strongest surface acidity and the appropriate redox ability compared with the other tested catalysts, thus exhibits the highest low-temperature NH3-SCR activity and better resistance to SO2 and H2O than 5W/Fe2O3-PO-400. The formation of low crystallinity and high dispersive gamma-Fe2O3 is an important reason on the good catalytic performance of magnetic 5W/Fe2O3-AO-400, which is also confirmed by the influence of annealing temperature. Furthermore, the results of steady-state kinetic experiments demonstrate that the 5W/Fe2O3-AO-400 catalyst mainly follows the Eley-Rideal mechanism.