Promotional mechanism of cerium oxide and titanium oxide doping on the low-temperature NH3-SCR activity of iron oxide
HU Qiang1, XIONG Zhi-bo1,2,3, BAI Peng1, WANG Yong-zhen1, WU Chao1, ZHOU Fei1,4, JIN Jing1,3, LU Chun-mei2
1. School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai 200093, China;
2. School of Energy and Power Engineering, Shandong University, Jinan 250061, China;
3. Collaborative Innovation Research Institute, University of Shanghai for Science & Technology, Shanghai 200093, China;
4. Jiangsu Guoxin Jingjiang Power LTD, Jingjiang 214500, China
X-ray diffraction, N2 adsorption, X-ray Photoelectron Spectroscopy and so on were used to characterize the catalysts surface crystallite, the structure and the active species dispersion of iron oxide after the doping of cerium oxide and titanium oxide. And the promotional mechanism of the low-temperature NH3-SCR activity over iron-based mixed oxide was revealed. The results indicated that the addition of cerium oxide and titanium oxide suppressed the formation of Fe2O3 crystallite in iron oxide and refined its pore size, and then increased the BET surface area and the pore volume of iron oxide. The oxideation-reduction electron pair of Ce4+ and Ce3+ was formed within iron oxide after the doping of cerium oxide. This made a large of adsorbed oxygen formed on the surface of iron-cerium mixed oxide catalyst, and enhanced its low-temperature catalytic oxidation of NO to NO2. Moreover, the adsorption strength of NH3 on the surface of iron oxide was enhanced after the doping of cerium oxide and titanium oxide, especially the low-temperature adsorption strength of NH3. These contributed to improve the low-temperature NH3-SCR activity over iron-based mixed oxides catalysts.
胡强, 熊志波, 白鹏, 武超, 王永贞, 周飞, 金晶, 路春美. 铈钛掺杂促进铁氧化物低温SCR脱硝性能的机理[J]. 中国环境科学, 2016, 36(8): 2304-2310.
HU Qiang, XIONG Zhi-bo, BAI Peng, WANG Yong-zhen, WU Chao, ZHOU Fei, JIN Jing, LU Chun-mei. Promotional mechanism of cerium oxide and titanium oxide doping on the low-temperature NH3-SCR activity of iron oxide. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(8): 2304-2310.
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