检索结果-南通市图书馆

Design of Ca-type todorokite catalysts with highly active for the selective reduction of NO_(x) by NH_(3) at low temperatures

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 697-708页

作者： Chuang Chang Zidi Yan Chunlei Zhang Yanshuang Zhang Miao Jiang Luna Ruan Min Xiao yunbo yu Hong He School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Ca-type todorokite catalysts were designed and prepared by a simple redox method and applied to the selective reduction of NO_(x) by NH_(3)(NH_(3)-SCR)for the first *** with the Na-type manjiroite prepared by the same method,the todorokite catalysts with different Mn/Ca ratios showed greatly improved catalytic activity for NO_(x) *** them,Mn8Ca4 catalyst exhibited the best NH_(3)-SCR performance,achieving 90%NO_(x) conversion within temperature range of 70-275℃ and having a high sulphur *** to the Na-type manjiroite sample,Ca-type todorokite catalysts possessed an increased size of tunnel,resulting in a larger specific surface *** increased the amounts of Ca doping,the Na content in Ca-type todorokite catalysts significantly decreased,providing larger amounts of Bronsted acid sites for NH_(3) adsorption to produce NH_(4)^(+).The NH_(4)^(+)species were highly active for reaction with NO+O_(2),playing a determining role in NH_(3)-SCR process at low ***,larger amounts of surface adsorbed oxygen contained over the Ca-doping samples than that over Na-type manjiroite,promoting the oxidation of NO and fast SCR *** the Ca-type todorokite catalysts,furthermore,nitrates produced during the flow of NO+O_(2),were more active for reaction with NH_(3) than that over Na-type manjiroite,benefiting the occurrence of NH_(3)-SCR *** study provides novel insights into the design of NH_(3)-SCR catalysts with high performance.

关键词： NO_(x) NH_(3)-SCR Mn-based oxides Ca-type todorokite Bronsted acid sites

Interface sites on vanadia-based catalysts are highly active for NO_(x) removal under realistic conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 523-536页

作者： Zhihui Lv Guangzhi He Wenshuo Zhang Jingjing Liu Zhihua Lian Yang Yang Zidi Yan Guangyan Xu Wenpo 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 and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China Ningbo Research Center for Urban Environment Chinese Academy of SciencesNingbo 315800China

TiO_(2)-supported V_(2)O_(5)catalysts are commonly used in NO_(x)reduction with ammonia due to their robust catalytic *** these catalysts,it is generally considered that the active species are mainly derived from the vanadia species rather than the intrinsic structure of V-O-Ti entities,namely the interface *** reveal the role of V-O-Ti entities in NH_(3)-SCR,herein,we prepared TiO_(2)/V_(2)O_(5)catalysts and demonstrated that V-O-Ti entities were more active for NO_(x)reduction under wet conditions than the V sites(V=O)working *** the V-O-Ti entities,kinetic measurements and first principles calculations revealed that NH_(3)activation exhibited a much lower energy barrier than that on V=O *** wet conditions,the V-O-Ti interface significantly inhibited the transformation of V=O to V-OH sites thus benefiting NH_(3)*** wet conditions,meanwhile,the migration of NH_(4)^(+)from Ti site neighboring the V-O-Ti interface to Ti site of the V-O-Ti interface was exothermic;thus,V-O-Ti entities together with neighboring Ti sites could serve as channels linking NH_(3)pool and active centers for activation of NH_(4)^(+).This finding reveals that the V-O-Ti interface sites on V-based catalysts play a crucial role in NO_(x)removal under realistic conditions,providing a new perspective on NH_(3)-SCR mechanism.

关键词： NO_(x)removal Vanadia-based catalysts V-O-Ti entities Interface sites Reaction mechanism

Influence of NO_(x) on the activity of Pd/θ-Al_(2)O_(3) catalyst for methane oxidation: Alleviation of transient deactivation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第2期34卷 38-47页

作者： Chang Cui Yan Zhang Wenpo 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 and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Ningbo Research Center for Urban Environment Chinese Academy of SciencesNingbo 315800China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

Alumina supported Pd catalyst(Pd/Al_(2)O_(3)) is active for complete oxidation of methane, while often suffers transient deactivation during the cold down process. Herein, heating and cooling cycle tests between 200 and 900 ℃ and isothermal experiments at 650 ℃ were conducted to investigate the influence of NO_(x) on transient deactivation of Pd/θ-Al_(2)O_(3) catalyst during the methane oxidation. It was found that the co-fed of NO alleviated transient deactivation in the cooling ramp from 800 to 500 ℃, which was resulted from the in situ formation of NO_(2) during the process of methane oxidation. Over the Pd/θ-Al_(2)O_(3), thermogravimetric analysis and O_(2) temperature programmed oxidation measurements confirmed that transient deactivation was due to the decomposition of Pd O particles and the hysteresis of Pd reoxidation, while the metal Pd entities were less active for methane oxidation than the Pd O ones. CO pulse chemisorption and scanning transmission electron microscopy characterizations rule out the NO_(2) effect on Pd size change. Powder X-ray diffraction and X-ray photoelectron spectroscopy characterizations were used to obtain palladium status of Pd/θ-Al_(2)O_(3) before and after reactions, indicating that in lean conditions at 650 ℃, the presence of NO_(2) increases the content of active Pd O on the catalyst surface, thus benefits methane oxidation. Homogeneous reaction between CH 4, O_(2), and NO_(x) may be partially responsible for the alleviation above 650 ℃. The interesting research of alleviation in transient deactivation by NO_(x), the components co-existing in exhausts, are of great significance for the application.

关键词： Methane Catalytic oxidation Palladium NO_(x)influence

Theoretical and experimental study on the inhibition of jet fuel oxidation by diarylamine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第4期56卷 225-232页

作者： Tinghao Jia yunbo yu Qing Liu Yao Yang Ji-Jun Zou Xiangwen Zhang Lun Pan Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311200China Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Antioxidants addition is believed as a facile and effective way to improve jet fuel thermal oxidation ***,amine antioxidants,as one of the most important antioxidants,have not received sufficient attention in the field of jet fuel autoxidation ***,the inhibition efficiency and mechanism of decane and exo-tetrahydrodicyclopentadiene(THDCPD)oxidation by di-4-tert-butylphenylamine(diarylamine)was experimentally and theoretically *** results show that diarylamine can significantly inhibit decane oxidation but is less efficient for THDCPD oxidation,which is attributed to the higher energy barrier of retro-carbonyl-ene reaction(rate-determining step)in THDCPD than that in decane during diarylamine ***,the addition of diarylamine will cause undesirable color change after accelerated oxidation and produce slightly more deposits during high-temperature thermal oxidative stress for both decane and *** results provide significant implications for the future design of effective antioxidant additives for high-performance jet fuel.

关键词： Jet fuel Thermal oxidation stability High-energy-density fuel Diarylamine Antioxidation mechanism

Autonomous multi-drone racing method based on deep reinforcement learning

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 35-48页

作者： yu KANG Jian DI Ming LI yunbo ZHAO yuhui WANG Department of Automation University of Science and Technology of China Institute of Advanced Technology University of Science and Technology of China Institute of Artificial Intelligence Hefei Comprehensive National Science Center College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Racing drones have attracted increasing attention due to their remarkable high speed and excellent maneuverability. However, autonomous multi-drone racing is quite difficult since it requires quick and agile flight in intricate surroundings and rich drone interaction. To address these issues, we propose a novel autonomous multi-drone racing method based on deep reinforcement learning. A new set of reward functions is proposed to make racing drones learn the racing skills of human experts. Unlike previous methods that required global information about tracks and track boundary constraints, the proposed method requires only limited localized track information within the range of its own onboard sensors. Further, the dynamic response characteristics of racing drones are incorporated into the training environment, so that the proposed method is more in line with the requirements of real drone racing scenarios. In addition, our method has a low computational cost and can meet the requirements of real-time racing. Finally, the effectiveness and superiority of the proposed method are verified by extensive comparison with the state-of-the-art methods in a series of simulations and real-world experiments.

关键词： autonomous multi-drone racing deep reinforcement learning Markov game racing drone sim-to-real

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

Coordinated Control of Fine-Particle and Ozone Pollution by the Substantial Reduction of Nitrogen Oxides

在线全文

学校读者我要写书评

暂无评论

Engineering 2022年第8期8卷 13-16页

作者： Biwu Chu Yan Ding Xiang Gao Junhua Li Tingyu Zhu yunbo yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of the Chinese Academy of Sciences Beijing 100049China Chinese Research Academy of Environmental Sciences Beijing 100012China State Environmental Protection Engineering Center for Coal-Fired Air Pollution Control Zhejiang UniversityHangzhou 310027China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

*** In recent years,the air quality in China has improved *** many cities,however,the concentration of fine particulate matter(PM_(2.5))remains higher than the secondary-level national ambient air quality standard(NAAQS level-2,35μg·m^(-3),GB3095-2012[1])and much higher than the first-level NAAQS(15μg·m^(-3),GB3095-2012[1])and the World Health Organization(WHO)air quality guidelines(5μg·m^(-3)).

关键词： Pollution Ozone ambient

Robust photo-assisted removal of NO at room temperature:Experimental and density functional theory calculation with optical carrier

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2023年第4期8卷 1102-1116页

作者： Yanqin Li Junqi Tian Zhisong Liu Zhongqi Liu Dong Dong Fu Wang Wei Wang Minmin Liu Jianming Dan Yongsheng Li Feng yu Bin Dai yunbo yu Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan School of Chemistry and Chemical EngineeringShihezi UniversityShihezi832003China Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing100085China FermiTech(Beijing)Co.Ltd. Beijing100083China School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai200240China Lab of Low-Dimensional Materials Chemistry Key Laboratory for Ultrafine Materials of Ministry of EducationShanghai Engineering Research Center of Hierarchical NanomaterialsSchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai200237China Bingtuan Industrial Technology Research Institute Shihezi UniversityShihezi832003China

Photo-assisted SCR(PSCR) offers a potential solution for removal of NO at room temperature. MnTiO_(x)as PSCR catalyst exhibits superior performance with NO removal of 100% at the room temperature. Electron paramagnetic resonance(EPR) analysis revealed the presence of numerous oxygen vacancies on MnTiO_(x). Optical carrier density functional theory(DFT) calculations showed that the threedimensional orbital hybridization of Mn and Ti is significantly enhanced under light irradiation. The MnTiO_(x)catalyst exhibited excellent electron–hole separation ability, which can adsorbe NH_(3)and dissociate to form NH_(2)fragments and H atoms. In-situ diffuse reflectance infrared fourier-transform spectroscopy(DRIFTS) indicated that the optical carrier enhanced NH_(3)adsorption on MnTiO_(x), which makes it possess excellent PSCR activity. This work provided an additional strategy to NO removal with PSCR catalysts and showed potential for use in photocatalysis.

关键词： Mixed metal oxide Photoselective catalytic reduction Photocatalyst Denitration Room-temperature catalysis

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

在线全文

学校读者我要写书评

暂无评论

稀土学报:英文版 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