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Investigation of the common intermediates over Fe-ZSM-5 in NH 3-SCR reaction at low temperature by in situ DRIFTS

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Journal of Environmental Sciences 2020年第8期32卷 32-39页

作者： xiaoyan shi Yingjie Wang Yulong Shan Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

The surface species formed in the reaction of NO and NO2 with pre-adsorbed NH 3 over a Fe-ZSM-5 catalyst(1.27 wt.%Fe,SiO2/Al2O3=25)at low temperature(140°C)were studied by in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).Through using a background spectrum of NH3-saturated Fe-ZSM-5,we clearly observed the formation of common intermediates resulting from the reaction of NO2 or NO+O2 with pre-adsorbed *** presents strong evidence that the oxidation of NO to form surface nitrates and nitrites is the key step for standard SCR at low *** addition,the results suggest that in the SCR reaction at low temperature,the NH^4+ions absorbed on Brønsted acid sites are less active than NH3 adsorbed on Lewis acid sites related to Fe species.

关键词： Fe-ZSM-5 NH 3-SCR SCR mechanism Intermediates In situ DRIFTS

Combination of biodiesel-ethanol-diesel fuel blend and SCR catalyst assembly to reduce emissions from a heavy-duty diesel engine

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Journal of Environmental Sciences 2008年第2期20卷 177-182页

作者： shi xiaoyan YU Yunbo HE Hong SHUAI shijin DONG Hongyi LI Rulong State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental of Sciences Chinese Academy of Sciences Beijing 100085 China State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China

In this study, the efforts to reduce NOx and particulate matter （PM） emissions from a diesel engine using both ethanol-selective catalytic reduction （SCR） of NOx over an Ag/Al2O3 catalyst and a biodiesel-ethanol-diesel fuel blend （BE-diesel） on an engine bench test are discussed. Compared with diesel fuel, use of BE-diesel increased PM emissions by 14% due to the increase in the soluble organic fraction （SOF） of PM, but it greatly reduced the Bosch smoke number by 60%-80% according to the results from 13-mode test of European Stationary Cycle （ESC） test. The SCR catalyst was effective in NOx reduction by ethanol, and the NOx conversion was approximately 73%. Total hydrocarbons （THC） and CO emissions increased significantly during the SCR of NOx process. Two diesel oxidation catalyst （DOC） assemblies were used after Ag/Al2O3 converter to remove CO and HC. Different oxidation catalyst showed opposite effect on PM emission. The PM composition analysis revealed that the net effect of oxidation catalyst on total PM was an integrative effect on SOF reduction and sulfate formation of PM. The engine bench test results indicated that the combination of BE-diesel and a SCR catalyst assembly could provide benefits for NOx and PM emissions control even without using diesel particle filters （DPFs）.

关键词： diesel engine biomass fuel selective catalytic reduction NOx particulate matter (PM)

Effects of a diesel oxidation catalyst on gaseous pollutants and fine particles from an engine operating on diesel and biodiesel

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Frontiers of Environmental Science & Engineering 2012年第4期6卷 463-469页

作者： xiaoyan shi Kebin HE Weiwei SONG Xingtong WANG Jihua TAN School of Environment Tsinghua UniversityBeijing 100084China Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

The effects of a diesel oxidation catalytic （DOC） converter on diesel engine emissions were investigated on a diesel bench at various loads for two steady-state speeds using diesel fuel and B20. The DOC was very effective in hydrocarbon （HC） and CO oxidation. Approximately 90%-95% reduction in CO and 36%-70% reduction in HC were realized using the DOC. Special attention was focused on the effects of the DOC on elemental carbon （EC） and organic carbon （OC） fractions in fine particles （PM2.5） emitted from the diesel engine. The carbonaceous compositions of PM2.5 were analyzed by the method of thermal/optical reflectance （TOR）. The results showed that total carbon （TC）, OC and EC emissions for PM2.5 from diesel fuel were generally reduced by the DOC. For diesel fuel, TC emissions decreased 22%-32% after the DOC depending on operating modes. The decrease in TC was attributed to 35%-97% decrease in OC and 3%-65% decrease in EC emissions. At low load, a significant increase in the OC/EC ratio of PMz.5 was observed after the DOC. The effect of the DOC on the carbonaceous compositions in PM2.5 from B20 showed different trends compared to diesel fuel. At low load, a slight increase in EC emissions and a significant decrease in OC/EC ratio of PM2.5 after DOC were observed for B20.

关键词： diesel oxidation catalyst (DOC) diesel particulate matters elemental carbon (EC) organic carbon (OC) biodiesel

A GEOMETRIC ALGORITHM FOR TILTED-CAMERA PERSPECTIVE PROJECTION AND THE COMPARISON WITH EXTERNAL PERSPECTIVE PROJECTION

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Geo-Spatial Information Science 1998年第1期1卷 79-84页

作者： shi xiaoyan[a] HU Yuju LU Xiangdong [a] School of Land Science WTUSM Wuhan China 430079

A geometric algorithm for Tilted-Camera Perspective（TCP）projec-tion is proposed in this paper based on the principle of perspective ***-cording to that,the difference between TCP projection and External Perspective（EXP）projection is *** is put forward prerequisites making these twoprojections were compatible,and some examples are given.

关键词： space perspective projection TCP projection EXP projection gemoetric algorithm compatible condition

Nano-sized alumina supported palladium catalysts for methane combustion with excellent thermal stability

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Journal of Environmental Sciences 2023年第4期126卷 333-347页

作者： Wei shi Guangyan Xu Xuewang Han Yingjie Wang Zhi Liu Sen Xue Nannan Sun xiaoyan shi Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Weichai Power Co. Ltd.Weifang 261061China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Pd/Al_(2)O_(3)catalysts supported on Al_(2)O_(3)of different particle sizes were synthesized and applied in methane *** catalysts were systematically characterized by Brunauer-Emmett-Teller (BET),X-ray diffraction (XRD),high resolution-transmission electron microscopy (HR-TEM),high-angle annular dark?eld-scanning transmission electron microscopy (HAADF-STEM),H_(2)-temperature-programmed reduction (H_(2)-TPR),O_(2)-temperature-programmed oxidation (O_(2)-TPO),X-ray photoelectron spectroscopy (XPS),and X-ray absorption?ne structure (XAFS).The characterization results indicated that nanosized Al_(2)O_(3)enabled the uniform dispersion of palladium nanoparticles,thus contributing to the excellent catalytic performance of these nano-sized Pd/Al_(2)O_(3)*** them,Pd/Al_(2)O_(3)-nano-10 (Pd/Al_(2)O_(3)supported by alumina with an average particle size of 10 nm)showed superior catalytic activity and stability for methane oxidation under harsh practical *** maintained excellent catalytic performance for methane oxidation for50 hr and remained stable even after harsh hydrothermal aging in 10 vol.%steam at 800℃ for 16 *** results revealed that the strong metal-support interactions and physical barriers provided by Al_(2)O_(3)-nano-10 suppressed the coalescence ripening of palladium species,and thus contributed to the superior sintering resistance of the Pd/Al_(2)O_(3)-nano-10 catalyst.

关键词： Methane combustion Pd/Al_(2)O_(3) Hydrothermal stability Metal-support interaction Physical barriers

Extruded monolith MnO_(x)-CeO_(2)-TiO_(2) catalyst for NH_(3)-SCR of low temperature flue gas from an industry boiler:Deactivation and recovery

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Journal of Rare Earths 2023年第9期41卷 1336-1343,I0002页

作者： Wei shi Jingjing Liu Ying Zhu Lin Zhao Yonggang Wang Zhaohuan Cheng Xueping Peng xiaoyan shi Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Tianjin Cement Industry Design&Research Institute Co LtdTianjin 300400China

The selective catalytic reduction(SCR) of NO_(x) with NH_(3)(NH_(3)-SCR) technology has been widely applied for reducing NO_(x) emissions from stationary and mobile *** this work,the extruded monolith MnO_(x)-CeO_(2)-TiO_(2) catalyst was installed in a cement kiln for NH_(3)-SCR of NO_(x),where the flue gas temperature was 110-140℃.It is found that the monolith catalyst is severely deactivated after operating for about 200 h with almost no NO_(x) conversion at 160℃ under GHSV of 50000 h^(-1),while the fresh monolith catalyst remains 60% NO_(x) *** electron microscopy-energy dispersive spectroscopy(SEM-EDS),X-ray photoelectron spectroscopy(XPS),temperature-programmed desorption of SO_(2)(SO_(2)-TPD) and thermogravimetric-differential thermal analysis(TG-DTG) experiments reveal that both MnO_(x) and CeO_(2) oxides in monolith are severely sulfated to manganese sulfate and cerium sulfate,and the external monolith walls are covered by massive ceria sulfate and little ammonium *** situ diffuse reflectance infrared Fourier trans form spectroscopy(DRIFTS) analysis demonstrates that the formation of nitrates at low temperatures is inhibited due to the occupation of active sites in MnO_(x)-CeO_(2)-TiO_(2) by sulfates,resulting in the decrease of low temperature *** washing with water,the activity of deactivated monolith catalyst can be partially recovered,together with significant loss of manganese and cerium from monolith.

关键词： Low temperature NH_(3)-SCR MnO_(x)-CeO_(2)-TiO_(2) Extruded monolith catalysts Deactivation Recovery Rare earths

Pampas grass-inspired FeOOH nanobelts as high performance anodes for sodium ion batteries

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Journal of Energy Chemistry 2021年第3期30卷 138-142页

作者： Lianyi Shao shige Wang Fangdan W u xiaoyan shi Zhipeng Sun Yuxin Tang School of Material and Energy Guangdong University of TechnologyGuangzhou 510006GuangdongChina China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China Institute of Applied Physics and Materials Engineering University of MacaoMacao 999078China

High-performance materials are the key to developing new alternative energy-storage systems[1-4].Sodium ion batteries(SIBs)are regarded as the promising large-scale electric energy storage owing to the high abundance and low cost of sodium resources[1,5-9].However,the sluggish kinetics of Na^(+)caused by the large-sized Na^(+)(1.02A)result in the lower energy density and unsatisfactory electrochemical properties[10-14].

关键词： Sodium ion batteries Anode materials Hydrothermal method Ex-situ techniques FeOOH nanobelts

A comparative study of particle size distribution from two oxygenated fuels and diesel fuel

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Frontiers of Environmental Science & Engineering 2010年第1期4卷 30-34页

作者： xiaoyan shi Kebin HE Jie ZHANG Yongliang MA Yunshan GE Jianwei TAN Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China National Laboratory of Auto Performance and Emission Test Beijing Institute of TechnologyBeijing 100081China

Oxygenated fuels are known to reduce particulate matter(PM)emissions from diesel *** this study,100%soy methyl ester(SME)biodiesel fuel(B100)and a blend of 10%acetal denoted by A-diesel with diesel fuel were tested as oxygenated *** size and number distributions from a diesel engine fueled with oxygenated fuels and base diesel fuel were measured using an Electrical Low Pressure Impactor(ELPI).Measurements were made at ten steady-state operational modes of various loads at two engine *** was found that the geometric mean diameters of particles from SME and Adiesel were lower than that from base diesel *** to diesel fuel,SME emitted more ultra-fine particles at rated speed while emitting less ultra-fine particles at maximum ***-fine particle number concentrations of A-diesel were much higher than those of base diesel fuel at most test modes.

关键词： oxygenated fuel diesel particulate matter particle size distribution biofuel

Paeonol reduces microbial metabolite α-hydroxyisobutyric acid to alleviate the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in atherosclerosis mice

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Chinese Journal of Natural Medicines 2023年第10期21卷 759-774页

作者： LIU Yarong WU Hongfei WANG Tian shi xiaoyan HE Hai HUANG Hanwen YANG Yulong DAI Min School of Pharmacy Anhui University of Chinese MedicineHefei 230012China Anhui Province Key Laboratory of Research and Development of Chinese Medicine Hefei 230012China

Gut microbiota dysbiosis is an avenue for the promotion of atherosclerosis(AS)and this effect is mediated partly via the circulating microbial *** microbial metabolites related to AS vascular inflammation,and the mechanisms involved need to be clarified ***(Pae)is an active compound isolated from Paeonia suffruticoas *** anti-As inflammation ***,considering the low oral bioavailability of Pae,it is worth exploring the mechanism by which Pae reduces the harmful metabolites of the gut microbiota to alleviate *** this study,ApoE--mice were fed a high-fat diet(HFD)to establish an AS *** mice were administrated with Pae(200 or 400 mg:kg')by oral gavage and fecal microbiota transplantation(FMT)was conducted.16S rDNA sequencing was performed to investigate the composition of the gut microbiota,while metabolomics analysis was used to identify the metabolites in serum and cecal *** results indicated that Pae significantly improved AS by regulating gut microbiota composition and microbiota metabolic profile in AS *** also identified a-hydroxyisobutyric acid(HIBA)as a harmful microbial metabolite reduced by *** supplementation in drinking water promoted AS inflammation in AS ***,vascular endothelial cells(VECs)were cultured and stimulated by *** verified that HIBA stimulation increased intracellular ROS levels,thereby inducing VEC inflammation via the TXNIP/NLRP3 *** sum,Pae reduces the production of the microbial metabolite HIBA,thus alleviating the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in *** study innovatively confirms the mechanism by which Pae reduces the harmful metabolites of gut microbiota to alleviate AS and proposes HIBA as a potential biomarker for AS clinical judgment.

关键词： Atherosclerosis Paeonol a-Hydroxyisobutyric acid Gut microbiota Vascular endothelial inflammation