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Room‐Temperature Activation of H2by a Surface Frustrated Lewis Pair

Angewandte Chemie 2019年第28期131卷

作者： Lu Wang Tingjiang Yan Rui Song Wei Sun Yuchan Dong Jiuli Guo Zizhong Zhang Xuxu Wang Geoffrey A. Ozin Department of Chemistry University of Toronto 80 St. George Street Toronto Ontario M5S3H6 Canada College of Chemistry and Chemical Engineering Qufu Normal University Qufu Shandong 273165 P. R. China International Research Center for Renewable Energy & State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an Shanxi 710049 P. R. China Department of Chemistry Nankai University Tianjin 300071 P. R. China State Key Laboratory of Photocatalysis on Energy and Environment College of Chemistry Fuzhou University Fuzhou 350108 P. R. China

Surface frustrated Lewis pairs (SFLPs) have been implicated in the gas‐phase heterogeneous (photo)catalytic hydrogenation of CO 2 to CO and CH 3 OH by In 2 O 3− x (OH) y . A key step in the reaction pathway is envisioned to be the heterolysis of H 2 on a proximal Lewis acid–Lewis base pair, the SFLP, the chemistry of which is described as In⋅⋅⋅In‐OH + H 2 → In‐OH 2 + ⋅⋅⋅In‐H − . The product of the heterolysis, thought to be a protonated hydroxide Lewis base In‐OH 2 + and a hydride coordinated Lewis acid In‐H − , can react with CO 2 to form either CO or CH 3 OH. While the experimental and theoretical evidence is compelling for heterolysis of H 2 on the SFLP, all conclusions derive from indirect proof, and direct observation remains lacking. Unexpectedly, we have discovered rhombohedral In 2 O 3− x (OH) y can enable dissociation of H 2 at room temperature, which allows its direct observation by several analytical techniques. The collected analytical results lean towards the heterolysis rather than the homolysis reaction pathway.

关键词： Gasphasenreaktionen Heterolytische H2-Dissoziation Indiumoxid Oberflächenchemie Oberflächenfrustriertes Lewis-Paar

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Oxidation Kinetics,Structural Changes and Element Migration during Oxidation Process of Vanadium-titanium Magnetite Ore

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Journal of Iron and Steel Research International 2016年第11期23卷 1160-1167页

作者： Feng PAN Qing-shan ZHU Zhan DU Hao-yan SUN State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100039China

The oxidation kinetics, structural changes, and elements migration during the oxidation process of the va- nadium-titanium magnetite （VTM） ore were analyzed. Kinetics analysis indicated that the oxidation process was con- trolled by diffusion control and could be divided into interface diffusion and lattice diffusion with apparent activation energy of 99.69 kJ/mol and 144.08 kJ/mol in the range of 800--1000℃, respectively. The surface structure changed with the oxidization temperature as follows： dense surface→nano sized sheets→submicron particles→molten particles. The compact structure changed into porous one because of the elements migration and enrichment. Both Fe and Ti elements migrated in the opposite direction during the oxidation process. The V etement in the raw ore stably existed in the form of V^5＋ state, some vanadium migrated and occupied the tetrahedral sites of the hematite during the oxidation process.

关键词： vanadium-titanium magnetite ore oxidation kinetics structural change element migration

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An LP-DOAS instrument with a laser driven light source for open-path measurement of atmospheric NO2 in Shanghai

An LP-DOAS instrument with a laser driven light source for o...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Mingzhi Li Jun Chen Mingxu Su Huinan Yang Arun Ramachandran Ravi Varma Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai China Department of Physics National Institute of Technology Calicut Calicut Kerala India

Shanghai is currently faced with the complex atmospheric pollution problem such as ozone (O 3 ) and PM2.5. O 3 is responsible for oxidization of atmospheric constituents that in turn produces secondary pollutants. Reducing atmospheric oxidation is the underpinning strategy for the prevention and control of pollution in this city. According to the observation data from the online automatic monitoring station of Shanghai, the city's O 3 concentration has been rising steadily. In 2013, there are 100 days with ozone as the main pollutants, accounted for 31.9%. By Leighton relationship (K 6 [O 3 ][NO]=K 4 [NO 2 ] = 1), concentration of O 3 is closely related to that of NO 2 . So, continuous monitoring of atmospheric NO 2 has important significance. An instrument was developed for measuring atmospheric NO 2 concentration using a powerful light source in conjunction with the long-path differential optical absorption spectroscopy (LP-DOAS) technique. This system installed at the central section of Shanghai used a laser driven light source (LDLS) and a sensitive TE cooled spectrometer. The LDLS showed better stability, high optical efficiency when compared to traditional arc lamp and light emitting diodes. The light sent into the atmosphere was returned by a retro reflecting mirror placed 1.3km away, and the light returned was sent to a high sensitive TE cooled spectrometer. The spectral range of measurement was 415-455nm and the spectra collected were averaged over 10 min, prior to analyzing for NO 2 concentration. Continuous observations were carried out for two weeks and the NO 2 concentration retrieved ranged from (20-600) ug/m3 with an estimated detection limit of 6.77 ug/m3. The measurement results indicate that it is feasible to use this instrument for detecting the NO 2 with high spatial and temporal sensitivity.

关键词： Absorption Atmospheric measurements Light sources Pollution measurement Optical sensors Wavelength measurement Instruments

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Numerical analysis of enhanced mixing in a Gallay tote blender

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Particuology 2016年第6期14卷 95-102页

作者： Xinxin Ren Guangzheng Zhou Ji xu Lijie Cui Wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Chemistry and Chemical Engineering University of Chinese Academy of Sciences Beijing 100049 China

The mixing performance of a multi-bladed baffle inserted into a traditional Gallay tote blender is explored by graphic processing unit-based discrete element method software. The mixing patterns and rates are investigated for a binary mixture, represented by two different colors, under several loading profiles. The baffle effectively enhances the convective mixing both in the axial and radial directions, because of the disturbance it causes to the initial flowing layer and solid-body zone, compared with a blender without a baffle. The axial mixing rate is affected by the gap between the baffle and the wall on the left and right sides, and an optimal blade length corresponds to the maximum mixing rate. However, the radial mixing rate increases with the blade length almost monotonically.

关键词： Powder mixing Tote blender Granular materials Discrete element method Simulation Baffle

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Polydimethylsiloxane assisted supercritical CO2 foaming behavior of high melt strength polypropylene grafted with styrene

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Frontiers of Chemical Science and engineering 2016年第3期10卷 396-404页

作者： Weixia Wang Shuai Zhou Zhong Xin Yaoqi Shi Shicheng Zhao Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and Technology Shanghai 200237 China State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai 200237 China Shanghai Key Laboratory of Catalysis Technology for Polyolefin Shanghai Research Institute of Chemical Industry Shanghai 200062 China

Foamable high melt strength polypropylene （HMSPP） was prepared by grafting styrene （St） onto polypropylene （PP） and simultaneously introducing poly- dimethylsiloxane （PDMS） through a one-step melt extru- sion process. The effect of PDMS viscosity on the foaming behavior of HMSPP was systematically investigated using supercritical CO2 as the foaming agent. The results show that the addition of PDMS has little effect on the grafting reaction of St and HMSPP exhibits enhanced elastic response and obvious strain hardening effect. Though the CO2 solubility of HMSPP with PDMS （PDMS-HMSPP） is lower than that of HMSPP without PDMS, especially for PDMS with low viscosity, the PDMS-HMSPP foams exhibit narrow cell size distribution and high cell density. The fracture morphology of PDMS-HMSPP shows that PDMS with low viscosity disperses more easily and uniformly in HMSPP matrix, leading to form small domains during the extrusion process. These small domains act as bubble nucleation sites and thus may be responsible for the improved foaming performance of HMSPP.

关键词： high melt strength polypropylene （HMSPP）,polydimethylsiloxane （PDMS） supercritical CO2 foaming behavior

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A NEW APPROACH TO SYNTHESIS OF MICRO/NANOSTRUCTURED SIOX/C COMPOSITE AS HIGH-PERFORMANCE ANODE MATERIAL FOR LITHIUM-ION BATTERIES

A NEW APPROACH TO SYNTHESIS OF MICRO/NANOSTRUCTURED SIOX/C C...

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第二十一届国际复合材料大会

作者： Pengpeng Lv Hailei Zhao Zhaolin Li School of Materials Science and Engineering University of Science and Technology Beijing State key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences

Nonstoichiometric silicon oxide（SiO） has attracted much attention due to its high theoretical capacity and stable cycling ***, the huge volume changes and low electrical conductivity restrict the practical applications of SiO anodes .Extensive trials have been devoted to coping with these problems, in a manner most of which involve direct utilization of commercial SiO powders,including physical mixing and ***, wet chemistry routes were actively investigated in SiO-based composite preparation with the aim of appropriately reducing the high cost of commercial SiO powders, using a simple and low-cost siloxane（e.g., tetraethoxysilane, TEOS） as raw *** this work, we employ citrate-nitrate gel combustion method for the first time to synthesize micro/nanostructured SiO/C *** the combustion process, carbon can be in situ introduced and uniformly dispersed in the SiO matrix, forming SiO/C composite.A simple carbon coating modification was adopted to further enhance the electrochemical performance of the SiO/C combustion production by creating a carbon outer layer on secondary particles and simultaneously decreasing the O/Si atomic ratio of the *** representation of SiO/C structure of the two kinds of samples is shown in *** the gel combustion process, the fast reaction releases large amount of gas, producing a highly porous intermediate product.A subsequent carbon coating process can not only introduce more carbon,but also recombine the granule structure, and thus leading to a homogeneous and dense contact between carbon and silicon oxide.A consequent extensive carbothermal reduction can bring a lower O/Si ratio and a higher specific reversible *** 1 shows the tested elemental composition and the calculated atomic ratio of oxygen to silicon of the two *** carbon content in SiO/C-A is ca.22.3%, and the x value（O/Si ratio） is calculated to be ca.1.82, which indicates that carbothermal r

关键词： Micro/nanostructure Citrate-nitrate gel combustion method Silicon suboxide Lithium-ion batteries

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Research progress concerning turbulent drag reduction of surfactant solution

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Huagong Jinzhan/Chemical Industry and engineering Progress 2016年第6期35卷 1660-1675页

作者： Wei, Jinjia Huang, Chonghai Xu, Na State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'anShaanxi710049 China

In turbulent flow drag reduction applications, surfactant additive is more applicable than polymer for the flow with high shear or in the closed circulation system due to its reversible mechanical degradation advantage. However, there is not enough understanding of the complicated rheology and drag-reduction mechanism of surfactant solution, limiting its practical application in the drag reduction field. This review introduces the research progress of surfactant drag reduction conducted by the authors in recent years on microstructure, complicated rheology characteristics, turbulent structure, as well as their relations with drag reduction and heat transfer, and analyzes the combined drag reduction effect of surfactant additives in the flow and microgroove fabricated on the wall. The stretch devices can significantly improve the heat transfer performance of surfactant drag-reducing flow with a lower pressure loss penalty. To the shortages of present surfactant drag reduction research, several suggestions are given for the future study. The first is to develop environmentally friendly and effective surfactant, the second is optimal design and layout of heat transfer enhancement device for drag-reducing flow, the third is the study on synergetic effect of drag reduction by combing surfactant drag reduction and other drag-reducing ways, and the final one is practical industrial application research on the scale-up, anticorrosion and persistence effect of surfactant drag reduction. © 2016, Chemical Industry Press. All right reserved.

关键词： Heat transfer

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Numerical simulation of complex membrane characteristics of elastic capsules

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Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2016年第2期37卷 337-341页

作者： Luo, Zheng-Yuan Bai, Bo-Feng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

Dynamics of elastic capsules (elastic membrane enclosing viscous fluid) under flow, which is determined by membrane mechanical characteristics, significantly influence mass transfer across the capsule membrane. Based on front tracking method, a three-dimensional model with considering membrane elasticity and bending resistance was developed to study the effect of bending resistance on the capsule deformation and membrane tensions. It is found that as the bending resistance increases, both the capsule deformation and membrane tensions decrease. Besides, the inclusion of bending resistance inhibits the formation of membrane buckles, thus enhances the membrane stability of capsules. © 2016, Science Press. All right reserved.

关键词： Membranes

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Hard‐Sphere Random Close‐Packed Au47Cd2(TBBT)31Nanoclusters with a Faradaic Efficiency of Up to 96 % for Electrocatalytic CO2Reduction to CO

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Angewandte Chemie 2019年第8期132卷

作者： Shengli Zhuang Dong Chen Lingwen Liao Yan Zhao Nan Xia Wenhao Zhang Chengming Wang Jun Yang Zhikun Wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and Nanotechnology CAS Center for Excellence in Nanoscience Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 P. R. China Institute of Physical Science and Information Technology Anhui University Hefei Anhui 230601 P. R. China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 P. R. China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei Anhui 230026 P. R. China

Metal nanoclusters have recently attracted considerable attention, not only because of their special size range but also because of their well‐defined compositions and structures. However, subtly tailoring the compositions and structures of metal nanoclusters for potential applications remains challenging. Now, a two‐phase anti‐galvanic reduction (AGR) method is presented for precisely tailoring Au 44 (TBBT) 28 to produce Au 47 Cd 2 (TBBT) 31 nanoclusters with a hard‐sphere random close‐packed structure, exhibiting Faradaic efficiencies of up to 96 % at −0.57 V for the electrocatalytic reduction of CO 2 to CO.

关键词： Cadmium CO2-Reduktion Elektrokatalyse Gold-Nanocluster Antigalvanische Reduktion

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Effects of surface wettability on boiling nucleation

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Kung Cheng Je Wu Li Hsueh Pao/Journal of engineering Thermophysics 2016年第1期37卷 111-115页

作者： Zheng, Wen-Xiu Li, Si-Jie Bai, Bo-Feng State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'an710049 China

We established a gas-liquid-solid three phase pool boiling system from molecular dynamics insight, introducing the interactions between the wall and the fluid as an additional force. The effects of wall wettability on the boiling nucleation were studied from three aspects of the nucleation position, the average kinetic energy and the interface contact thermal resistance. The results show that strong surface wettability means strong constraint to the near surface molecules and gas nuclear position is farther from the surface. For stronger surface wettability, the molecular average kinetic energy for the molecules adjacent to the surface is significantly larger than that for the molecules far from the surface, for weaker surface wettability, molecular kinetic energy has a uniform distribution in the vertical direction of the wall. As increasing the surface wettability the interface contact thermal resistance increases and accordingly the boiling nucleation is weakened. © 2016, Science Press. All right reserved.

关键词： Nucleation

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