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The selective catalytic reduction of NO over Ce_(0.3)TiO_x^-supported metal oxide catalysts

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Journal of Environmental Sciences 2018年第3期30卷 1-7页

作者： Zhichen duan Jian Liu Juan Shi Zhen Zhao Yuechang Wei Xiao Zhang Guiyuan Jiang aijun duan State Key Laboratory of Heavy Oil Processing Beijing Key Lab of Oil & Gas Pollution Control China University of Petroleum

A Ce（0.3）TiOxoxide carrier was synthesized via a sol–gel process,and Ce（0.3）TiOxsupported metal（M=Cd,Mn,Fe,W,Mo）oxide catalysts were prepared by the method of incipient-wetness *** catalysts were characterized by means of X-ray diffraction（XRD）,Brunauer–Emmett–Teller（BET）analysis,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared（FT–IR）spectroscopy,UV–Visdiffusereflectancespectroscopy（UV–VisDRS）,and Temperature-programmed reduction with H2（H2-TPR）.The catalytic activities for de-NO（x ）were evaluated by the NH3-SCR *** all the catalysts tested,the 2 wt.%Cd/Ce（0.3）TiOxcatalyst exhibited the best NH3-SCR performance,with a wide temperature window of 250–450℃ for NO conversion above 90%.Moreover,the catalyst showed N2 selectivity greater than 99%from 200 to 450℃.

关键词： NOx NH3-SCR Catalyst Selectivity Ce-Ti oxide

Selective hydrocracking of light cycle oil into high-octane gasoline over bi-functional catalysts

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Journal of Energy Chemistry 2021年第1期30卷 41-50,I0002页

作者： Zhengkai Cao Xia Zhang Chunming Xu Xinlu Huang Ziming Wu Chong Peng aijun duan State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116041LiaoningChina

Light cycle oil(LCO) with high content of poly-aromatics was difficult to upgrade and convert,which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable *** hydrocracking behaviors of typical aromatics in LCO of naphthalene and tetralin were investigated over NiMo and CoMo *** characterization methods including N2-adsoprtion and desorption,ammonia temperature-programmed desorption(NH3-TPD),Pyridine infrared spectroscopy(Py-IR),CO infrared spectroscopy(CO-IR),Raman and X-ray photoelectron spectroscopy(XPS) were applied to determine the properties of different *** results showed that CoMo catalyst with high concentration of S-edges could hydrosaturate more naphthalene to tetralin but exhibit lower yield of high-value light aromatics(carbon numbers less than 10) than NiMo *** catalyst with high concentration of Mo-edges also presented a higher selectivity of converting naphthalene into cyclanes than CoMo ***,the naphthalene and LCO hydrocracking performances were also investigated over different catalysts *** activity evaluation and kinetic analysis results showed that the naphthalene hydrocracking conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same condition.A stepwise reaction principle was proposed to explain the high efficiency of CoMo-AY/NiMoAY grading ***,the LCO hydrocracking evaluation results confirmed that CoMo-AY/NiMoAY catalysts grading system with low carbon deposition and high stability could remain high percentage of active phases,which was more efficient to convert LCO to high-octane gasoline.

关键词： Hydrocracking Conversion Selectivity Catalysts grading High-octane gasoline

Supported single Au（Ⅲ） ion catalysts for high performance in the reactions of 1,3-dicarbonyls with alcohols

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Nano Research 2016年第4期9卷 985-995页

作者： Daowei Gao Xin Zhang Ying Yang Xiaoping Dai Hui Sun Yuchen Qin aijun duan State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China

The high cost and poor atom utilization efficiency of noble metal catalysts have limited their industrial applications. Herein, we designed CeO2-supported single Au（Ⅲ） ion catalysts with ultra-low gold loading that can enhance the utilization efficiency of gold atoms and bridge the gap between homogeneous and heterogeneous gold catalysis. These catalysts were highly active and reusable for the reaction of 1,3-dicarbonyls with alcohols. The catalytic turnover number of CeO2-supported single Au（III） ion catalysts was much higher than that of the homogeneous catalyst NaAuCI4. In addition, the effects of gold loading and the drying method for the catalysts on the organic reactions were systematically explored. In-depth investigation of the structure-property relationship by high- resolution transmission electron microscop~ hydrogen temperature-programmed reduction, X-ray absorption near edge structure analysis, UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy revealed that the isolated Au（III） ions were related to the active sites for the synthesis of β-substituted cyclohexenone and that CeO2 was responsible for yielding ketonic ester.

关键词： single Au(Ⅲ) ion heterogeneous catalysts green chemistry 1 3-dicarbonyls

Effect of yttrium on catalytic performance of Y-doped TiO_(2) catalysts for propane dehydrogenation

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Journal of Rare Earths 2024年第5期42卷 962-971,I0005页

作者： Liyu Hou Liming Xia Ruipeng Zhou Jianmei Li Renjie Li Zhen Zhao Guimei Yuan aijun duan State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang110034China

Defective bulk catalysts based on TiO_(2) have superior catalytic performance for propane dehydrogenation(PDH).The oxygen vacancy concentration and the number of active sites on the catalyst surface can be effectively tuned by doping metal in TiO_(2).Herein,yttrium(Y)-doped titanium dioxide(nY/TiO_(x))catalysts were in-situ synthesized via the coprecipitation method to study the effect of rare earth metal Y doping on the structure of TiO_(2) and the catalytic performance for *** results demonstrate that Ydoped TiO_(2) exhibits higher catalytic activity,propylene selectivity and stability than bare TiO_(2).Full characterizations with X-ray diffraction(XRD),high-resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS),infrared spectroscopy of pyridine adsorption(Py-IR),temperature-programmed desorption of ammonia(NH_(3)-TPD),H_(2) temperature-programmed reduction(H_2-TPR),and Raman techniques on these catalysts reveal that Y^(3+)can enter TiO_(2) lattice,and the lattice stability of the catalyst can be enhanced by replacing Ti^(4+)to form Y-O-Ti ***,the introduction of an appropriate amount of Y can obviously promote the PDH reaction by adjusting the acidity of the catalyst,improving the release capacity of TiO_(2) lattice oxygen and increasing the formation of active ***,excessive Y doping will lead to pore clogging,and the exposure of active sites will be reduced,resulting in the degradation of catalytic performance.

关键词： Propane dehydrogenation Anatase Lattice defects Coordinatively unsaturated Ti cations Oxygen vacancy Rare earths

Effect of Ce doping of TiO_2 support on NH_3-SCR activity over V_2O_5–WO_3/CeO_2–TiO_2 catalyst

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Journal of Environmental Sciences 2014年第10期26卷 2106-2113页

作者： Kai Cheng Jian Liu Tao Zhang Jianmei Li Zhen Zhao Yuechang Wei Guiyuan Jiang aijun duan State Key Laboratory of Heavy Oil Processing China University of Petroleum

CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction（SCR） of NOx with NH3 were prepared by an incipient-wetness impregnation method. These catalysts were characterized by means of BET, XRD, UV–Vis,Raman and XPS techniques. The results showed that the catalytic activity of V2O5–WO3/TiO2 was greatly enhanced by Ce doping（molar ratio of Ce/Ti = 1/10） in the TiO2 *** catalysts that were predominantly anatase TiO2 showed better catalytic performance than the catalysts that were predominantly fluorite CeO2. The Ce additive could enhance the surface adsorbed oxygen and accelerate the SCR reaction. The effects of O2 concentration, ratio of NH3/NO, space velocity and SO2 on the catalytic activity were also investigated. The presence of oxygen played an important role in NO reduction. The optimal ratio of NH3/NO was 1/1 and the catalyst had good resistance to SO2 poisoning.

关键词： CeO2–TiO2 SCR Nitrogen oxides Homogeneous precipitation method SO2poisoning

NH_3-SCR denitration catalyst performance over vanadium–titanium with the addition of Ce and Sb

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Journal of Environmental Sciences 2015年第5期27卷 74-80页

作者： Chi Xu Jian Liu Zhen Zhao Fei Yu Kai Cheng Yuechang Wei aijun duan Guiyuan Jiang State Key Laboratory of Heavy Oil China University of PetroleumBeijing Department of Agricultural and Biological Engineering Mississippi State University130 Creelman St Mississippi StateMS 39762United States

Selective catalytic reduction technology using NH3 as a reducing agent（NH3-SCR） is an effective control method to remove nitrogen oxides. TiO2-supported vanadium oxide catalysts with different levels of Ce and Sb modification were prepared by an impregnation method and were characterized by X-ray diffractometer（XRD）, Brunauer-Emmett-Teller（BET）, Transmission electron microscopy（TEM）, Fourier transform infrared spectroscopy（FT-IR）, UV-Vis diffuse reflectance spectroscopy（UV-Vis DRS）, Raman and Hydrogen temperature-programmed reduction（H2-TPR）. The catalytic activities of V5 CexS by/TiO2 catalysts for denitration were investigated in a fixed bed flow microreactor. The results showed that cerium, vanadium and antimony oxide as the active components were well dispersed on TiO2, and the catalysts exhibited a large number of d-d electronic transitions, which were helpful to strengthen SCR reactivity. The V5 CexS by/TiO2 catalysts exhibited a good low temperature NH3-SCR catalytic activity. In the temperature range of 210 to 400℃, the V5 CexS by/TiO2 catalysts gave NO conversion rates above 90%. For the best V5Ce35Sb2/TiO2 catalyst, at a reaction temperature of 210℃, the NO conversion rate had already reached 90%. The catalysts had different catalytic activity with different Ce loadings. With the increase of Ce loading, the NO conversion rate also increased.

关键词： VCeSb/TiO2 catalyst SCR Denitration Low temperature N2 selectivity

Effects of Calcination Temperature on the Acidity and Catalytic Performances of HZSM-5 Zeolite Catalysts for the Catalytic Cracking of n-Butane

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Journal of Natural Gas Chemistry 2005年第4期14卷 213-220页

作者： Jiangyin Lu Zhen Zhao Chunming Xu aijun duan Pu Zhang State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China

The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature （excluding 800 ℃）. The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature. The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5 zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.

关键词： HZSM-5 zeolite catalyst acidic modification calcination temperature n-butane catalytic cracking olefin

Pt-confinement catalyst with dendritic hierarchical pores on excellent sulfur-resistance for hydrodesulfurization of dibenzothiophene and 4,6-dimethyldibenzothiophene

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Green Energy & Environment 2022年第2期7卷 324-333页

作者： Xilong Wang Chengkun Xiao Mohnnad H.Alabsi Peng Zheng Zhengkai Cao Jinlin Mei Yu Shi aijun duan Daowei Gao Kuo-Wei Huang Chunming Xu State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing102249China KAUST Catalysis Center and Division of Physical Sciences and Engineering King Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia School of Chemistry and Chemical Engineering University of JinanJinan250022China

Metal confinement catalyst Mo S_(2)/Pt@TD-6%Ti(TD,TS-1/Dendritic mesoporous silica nanoparticles composite) in dendritic hierarchical pore structures was synthesized and showed excellent sulfur-resistance performance and stabilities in catalytic hydrodesulfurization reactions of probe sulfide *** Mo S_(2)/Pt@TD-6%Ti catalyst combines the concepts of Pt-confinement effect and hydrogen spillover of Pt noble *** modified micropores of Mo/Pt@TD-6%Ti only allow the migration and dissociation of small H_(2) molecules(0.289 nm),and effectively keep the sulfur-containing compounds(e.g.H_(2)S,0.362 nm) ***,the Mo S_(2)/Pt@TD-6%Ti catalyst exhibits higher DBT and 4,6-DMDBT HDS activities because of the synergistic effect of the strong H_(2) dissociation ability of Pt and desulfurization ability of Mo S_(2) with a lower catalyst *** new concept combining H2dissociation performance of noble metal catalyst with the desulfurization ability of transition metal sulfide Mo S_(2) can protect the noble metal catalyst avoiding deactivation and poison,and finally guarantee the higher activities for DBT and 4,6-DMDBT HDS.

关键词： catalyst sulfur pores

Morphology-selective synthesis of active and durable gold catalysts with high catalytic performance in the reduction of 4-nitrophenol

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Nano Research 2016年第10期9卷 3099-3115页

作者： Daowei Gao Xin Zhang Xiaoping Dai Yuchen Qin aijun duan Yanbing Yu Hongying Zhuo Hairui Zhao Pengfang Zhang Yan Jiang Jianmei Li Zhen Zhao State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China College of Science China University of Petroleum Beijing 102249 China

A series of novel catalysts consisting of nanosized Au particles confined in micro-mesoporous ZSM-5/SBA-15 （ZSBA） materials with platelet （PL）, rod （RD）, and hexagonal-prism （HP） morphologies have been synthesized in situ. These catalysts possess both SBA-15 and ZSM-5 structures and exhibit excellent stability of their active sites by confinement of the Au nanoparticles （NPs） within ZSBA. The catalysts have been characterized in depth to understand their structure-property relationships. The gold NP dimensions and the pore structure of the catalysts, which were found to be sensitive to calcination temperature and synthetic conditions, are shown to play vital roles in the reduction of 4-nitrophenol. Au/ZSBA-PL, with short mesochannels （210 nm） and a large pore diameter （6.7 nm）, exhibits high catalytic performance in the reduction of 4-nitrophenol, whereas Au/ZSBA-HP and Au/ZSBA-RD, with long mesochannels and relatively smaller pore sizes, show poor catalytic activities. In the case of catalysts with different gold NP sizes, Au/ZSBA-PL-350 with an Au NP diameter of 4.0 nm exhibits the highest reaction rate constant （0.14 min-1） and turnover frequency （0.0341 s-1）. In addition, the effect of the reaction parameters on the reduction of 4-nitrophenol has been systematically investigated. A possible mechanism for 4-nitrophenol reduction over the Au/ZSBA catalysts is proposed.

关键词： gold catalysis porous material environmental pollution 4-nitrophenol