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| 1 | Low-temperature SCR activity and SO_2 deactivation mechanism of Ce-modified V_2O_5–WO_3/TiO_2 catalyst显示文摘The promotion effect of ceria modi fi cation on the low-temperature activity of V2O5-WO3/TiO2 catalyst was evaluated for the selective catalytic reduction of NO with NH3(NH3-SCR). The catalytic activity of 1 wt% V2O5-WO3/TiO2 was signi fi cantly enhanced by the addition of 8 wt%ceria, which exhibited a NO x conversion above 80% in a broad temperature range 190–450 1C. This performance was comparable with 3 wt%V2O5-WO3/TiO2, indicating that the addition of ceria contributed to reducing the usage of toxic vanadia in developing low-temperature SCR catalysts. Moreover, V1 Ce WTi exhibited approximately 10% decrease in NOx conversion in the presence of 60 ppm SO2. The characterization results indicated that active components of V, W and Ce were well dispersed on TiO2 support. The synergetic interaction between Ce and V species by forming V–O–Ce bridges enhanced the reducibility of VCe WTi catalyst and thus improved the low-temperature activity. The sulfur poisoning mechanism was also presented on a basis of the designed TPDC(temperature-programmed decomposition) and TPSR(temperatureprogrammed surface reaction) experiments. The deposition of(NH4)2SO4on V1 Ce WTi catalyst was much smaller compared with that on V1 Ti.On the other hand, the oxidation of SO2 to SO3was signi fi cantly promoted on the CeO2-modi fi ed catalyst, accompanied by the formation of cerium sulfates. Therefore, the deactivation of this catalyst was mainly attributed to the vanishing of the V–Ce interaction and the sulfation of active ceria. | Ziran Ma Xiaodong Wu Ya Feng Zhichun Si Duan Weng Lei Shi | 2015 | Progress in Natural Science:Materials International2015，25，4： | 29 |
| 2 | Effects of WOx modification on the activity, adsorption and redox properties of CeO_2 catalyst for NO_x reduction with ammonia显示文摘A series of WO3/CeO2 (WOx/CeO2) catalysts were synthesized by wet impregnation of ammonium metatungstate on a CeO2 support. The resulting solid acid catalysts were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy (UV-Vis), Raman spectroscopy (Raman), in-situ Fourier transform infrared spectroscopy (in-situ FT-IR) of ammonia adsorption, NH3-TPD, H2 temperature-programmed reduction (H2-TPR), NH3/NO oxidation and activity measurements for NOx reduction by NH3 (NH3-SCR). The results show that polytungstate (WOx) species are the main species of tungsten oxide on the surface of ceria. The addition of tungsten oxide enhances the Bro¨nsted acidity of ceria catalysts remarkably and decreases the amount of surface oxygen on ceria, with strong interaction between CeO2 and WOx. As a result, the N2 selectivity of NH3 oxidation and NH3-SCR at high temperatures (> 300℃) is enhanced. Therefore, a wide working temperature window in which NOx conversion exceeds 80% (NOx conversion > 80%) from 200 to 450℃, is achieved over 10 wt.% WOx/CeO2 catalyst. A tentative model of the NH3-SCR reaction route on WOx/CeO2 catalysts is presented. | Ziran Ma Duan Weng Xiaodong Wu Zhichun Si | 2012 | Journal of Environmental Sciences2012，24，7： | 23 |
| 3 | Synergistic effect between ceria and tungsten oxide on WO_3-CeO_2-TiO_2 catalysts for NH_3-SCR reaction | Lei Chen Duan Weng Zhichun Si Xiaodong Wu | 2012 | Progress in Natural Science:Materials International2012，22，4： | 11 |
| 4 | Chemical deactivation of V2Os-WO3/Ti02 SCR catalyst by combined effect of potassium and chloride显示文摘 | Xiaodong WU Wenchao YU Zhichun SI Duan WENG | 2013 | Frontiers of Environmental Science & Engineering2013，7，3： | 9 |
| 5 | Modification of CeO_2-ZrO_2 catalyst by potassium for NOx-assisted soot oxidation显示文摘Potassium-modified ceria-zirconia catalyst was synthesized by wetness impregnation method.The ageing treatment was performed in static air at 800°C for 20 hr to evaluate the thermal stability of the catalyst.The catalysts were characterized by X-ray diffraction,BET surface area,oxygen storage capacity,NOx-temperature programmed desorption and soot-temperature programmed oxidation measurements.By introduction of potassium,the maximum soot oxidation rate temperature(Tm) of the ceria-zirconia based catalyst decreased from 525 to 428°C in the presence of NO under a loose contact mode.The shift of Tm of the K-modified catalyst after ageing is only 15°C.The enhanced activity of the aged catalyst mainly lies in the promotional effect of potassium on the NOx/oxygen storage capacity as well as the soot-catalyst contact. | DuanWeng Jia Li, Xiaodong Wu Zhichun Si | 2011 | Journal of Environmental Sciences2011，23，1： | 7 |
| 6 | Effect of water vapor on NH_3–NO/NO_2 SCR performance of fresh and aged MnO_x–NbO_x–CeO_2 catalysts显示文摘A MnOx–NbOx–CeO2 catalyst for low temperature selective catalytic reduction(SCR) of NOx with NH3 was prepared by a sol–gel method, and characterized by NH3–NO/NO2 SCR catalytic activity, NO/NH3 oxidation activity, NOx/NH3 TPD, XRD, BET, H2-TPR and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy(DRIFTS). The results indicate that the Mn Ox–Nb Ox–CeO2 catalyst shows excellent low temperature NH3-SCR activity in the temperature range of 150–300℃. Water vapor inhibits the low temperature activity of the catalyst in standard SCR due to the inhibition of NOx adsorption. As the NO2 content increases in the feed, water vapor does not affect the activity in NO2 SCR. Meanwhile, water vapor significantly enhances the N2 selectivity of the fresh and the aged catalysts due to its inhibition of the decomposition of NH4NO3 into N2O. | Lei Chen Zhichun Si Xiaodong Wu Duan Weng Zhenwei Wu | 2015 | Journal of Environmental Sciences2015，27，5： | 6 |
| 7 | Optimizing the crystallinity and acidity of H-SAPO-34 by fluoride for synthesizing Cu/SAPO-34 NH_3-SCR catalyst显示文摘A series of H-SAPO-34 zeolites were synthesized by a hydrothermal method in fluoride media.The as-synthesized H-SAPO-34 zeolites were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),N_2 physisorption,temperature-programmed desorption of NH_3(NH_3-TPD) and nuclear magnetic resonance(NMR) measurements.The results showed that a certain concentration of F- anions promoted the nucleation and crystallization of H-SAPO-34.The H-SAPO-34 synthesized in the fluoride media showed high crystallinity,uniform particle size distribution,large specific surface area and pore volume,and enhanced acidity.Therefore,Cu/SAPO-34 based on the fluoride-assisted zeolite showed a broadened temperature window for the selective catalytic reduction of NO by NH_3(NH_3-SCR) reaction due to the enhanced acidity of the zeolite and the improved dispersion of copper species. | Jing Ma Zhichun Si Xiaodong Wu Duan Weng Yue Ma | 2016 | Journal of Environmental Sciences2016，28，3： | 5 |
| 8 | Highly dispersed iron species created on alkali-treated zeolite for ammonia SCR显示文摘Alkaline treatment using sodium hydroxide was introduced to obtain a hierarchical pore structure in H-ZSM-5 zeolite.Fe-exchanged zeolite catalysts were prepared by impregnation on the original and alkali-treated zeolites,and were evaluated for NOx reduction by NH3,NO oxidation,and NH3 oxidation reactions.The highly dispersed iron species as active sites can be obtained by controlling the pore structure and particle size of zeolite.Therefore,the Fe/ZSM-5 catalyst treated mildly by sodium hydroxide before iron exchange,which contains amounts of highly dispersed Fe species,obtains over80% NOx conversion at a wide temperature range of 250-500℃. | Jing Ma Duan Weng Xiaodong Wu Zhichun Si Zhenwei Wu | 2013 | Progress in Natural Science:Materials International2013，23，5： | 3 |
| 9 | Size effect of Pt nanoparticles in acid-assisted soot oxidation in the presence of NO显示文摘Pt/Al2O3 catalysts with mean Pt particle size ranged from 2.7 to 7.1 nm were synthesized by chemical reduction method,and the sulfated counterparts were prepared by impregnation of sulfuric acid.The turnover frequency of platinum for soot oxidation under loose contact conditions in a feed flow containing NO and O2 are positively correlated with the size of platinum.The sulfated Pt/Al2O3 exhibits higher catalytic activity for soot oxidation in the presence of NO despite their reduced ability for NO2 production.Such a contradiction is more significant for those catalysts with smaller platinum particles.Herein,the catalysts were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),transmission electron microscopy(TEM),inductive coupled plasma(ICP)emission spectrometry,CO chemisorption,thermogravimetric analysis(TGA),NH3 temperature-programmed desorption(NH 3-TPD),NO temperature-programmed oxidation(TPO)and NO x temperatureprogrammed desorption(TPD).Possible effect of Pt particle size for the catalytic oxidation of soot in the presence of NO was presented based primarily on the promoted NO2 transfer efficiency onto the soot pushed by the acidic catalysts. | Shuting Luo Xiaodong Wu Baofang Jin Shuang Liu Rui Ran Zhichun Si Duan Weng | 2020 | Journal of Environmental Sciences2020，32，8： | 1 |
| 10 | Struc- ture, acidity and activity of CuOx/WOx ZrO2 catalyst for selective catalytic reduction of NO by NH3 显示文摘 | Si Zhichun Weng Duan Wu Xiaodong | 2010 | Journal of Catalysis2010，271，1： | 1 |
| 11 | Influences of impregnation procedure on the SCR activity and alkali resistance of V,05-W03/TiO, catalyst显示文摘 | Yu Wenchao Wu Xiaodong Si Zhichun Weng Duan | 2013 | Applied Surface Science2013，283，： | 1 |
| 12 | Photoinduced hydroxyl radical and photocatalytic activity of samarium-doped TiO 2 nanocrystalline显示文摘 | Qi Xiao Zhichun Si Jiang Zhang Chong Xiao Xiaoke Tan | 2007 | Journal of Hazardous Materials2007，，1： | 1 |
| 13 | Characterization andphotocatalytic activity of Sm^3+-doped TiO2 nanocrystalline preparedby low temperature combustion method显示文摘 | XIAO Qi SI Zhichun YU Zhiming | 2008 | Journal of Alloys andCompounds2008，450，12： | 1 |
| 14 | Sol-gel auto-combustionsynthesis of samarium-doped TiO2 nanoparticles and theirphotocatalytic activity under visible light irradiation显示文摘 | XIAO Qi SI Zhichun YU Zhiming | 2007 | MaterialsScience and Engineering:B2007，137，： | 1 |
| 15 | Progress on metal-support interactions in Pd-based catalysts for automobile emission control显示文摘The interactions between metals and oxide supports,so-called metal-support interactions(MSI),are of great importance in heterogeneous catalysis.Pd-based automotive exhaust control catalysts,especially Pd-based three-way catalysts (TWCs),have received considerable research attention owing to its prominent oxidation activity of HCs/CO,as well as excellent thermal stability.For Pd-based TWCs,the dispersion,chemical state and thermal stability of Pd species,which are crucial to the catalytic performance,are closely associated with interactions between metal nanoparticles and their supporting matrix.Progress on the research about MSI and utilization of MSI in advanced Pd-based three-way catalysts are reviewed here.Along with the development of advanced synthesis approaches and engine control technology,the study on MSI would play a notable role in further development of catalysts for automobile exhaust control. | Yidan Cao Rui Ran Xiaodong Wu Zhichun Si Feiyu Kang Duan Weng | 2023 | Journal of Environmental Sciences2023，，3： | 1 |
| 16 | Deactivation of Cu-SAPO-34 by urea-related deposits at low temperatures and the regeneration显示文摘Selective catalytic reduction(SCR) with urea catalyzed by Cu-SAPO-34 is an effective method to eliminate NO_x from diesel exhaust. However, urea-related deposits may form during cold-start and urban driving due to low exhaust temperatures. The activity of CuSAPO-34 at 175°C is significantly degraded by urea exposure, and 300°C is required for regeneration. Through in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS) and temperature-programmed hydrolysis studies, the dominant stable deposit at 175°C is identified as biuret, which can be eliminated at 300°C. The urea-derived deactivation and regeneration mechanisms of Cu-SAPO-34 were compared with those of anatase-supported catalysts. | Yue Ma Xiaodong Wu Junyu Zhang Rui Ran Zhichun Si Duan Weng | 2019 | Journal of Environmental Sciences2019，31，7： | 1 |
| 17 | Characterization and photocatalytic activity of Sm3+-doped TiO2 nanocrystalline prepared by low temperature combustion method显示文摘 | Qi Xiao Zhichun Si Zhiming Yu | 2006 | Journal of Alloys and Compouds2006，23，： | 1 |
| 18 | Characterization and photocatalytic activity of Sm^3+-doped TiO2 nanocrystaUine prepared by low temperature combustion method 显示文摘 | XIAO Qi SI Zhichun YU Zhiming | 2008 | J Alloys Compound2008，450，： | 1 |
| 19 | Characterization and photocatalytic activity of Sm { Sup3 +}-do ped TiO2 { Sub2 } nanoerystalline prepared by low temperature combustion method显示文摘 | XIAO Qi SI Zhichun YU Zhiming | 2008 | Journal of Alloys and Compounds2008，450，12： | 1 |
| 20 | Sol-gel auto-combustion synthesis of samarium-doped TiO2 nanoparticles and their photocatalyric activity under visible light irradiation 显示文摘 | XIAO Qi SI Zhichun YU Zhiming | 2007 | Mater Sci Eng B2007，137，13： | 1 |
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