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Synthesis of powdered silver nanoparticles using hydrogen in aqueous medium

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Particuology 2012年第1期10卷 140-143页

作者： Kushal D. Bhatte Krishna M.Deshmukh Yogesh P.Patil Dinesh N.Sawant Shin-Ichiro Fujita Masahiko Arai Bhalchandra M.Bhanage Department of Chemistry Institute of Chemical Technology chemical Process Engineering divison Graduate School of EngineeringHokkaido University

Environmentally benign one-pot protocol is used in the synthesis of silver nanoparticles （AgNPs） in powder form, involving the reduction of silver nitrate in the presence of fully hydrolyzed polyvinyl alcohol （PVA） as stabilizer by hydrogen （H2） as reducing agent in aqueous medium. Fully hydrolyzed biodegradable PVA has extremely low cytotoxicity, making it a favorable stabilizer from green perspective. In the present methodology, essentially naked silver nanoparticles are obtained in good yield. The prepared sil- ver nanoparticles were characterized by TEM, XRD, EDAX, UV-Vis spectroscopy and DLS histogram, and studied for its activity as a recyclable catalyst for synthesis of different enaminones.

关键词： Silver nanoparticlesAqueous mediaHydrogenCatalysisEnaminones synthesis

Imaging the influence of oxides on the electrostatic potential of photovoltaic InP nanowires

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Nano Research 2021年第11期14卷 4087-4092页

作者： Lukas Hrachowina Xianshao Zou Yang Chen Yuwei Zhang Enrique Barrigón Arkady Yartsev Magnus T.Borgström NanoLund Lund UniversityBox 11822100LundSweden divison of Solid State physics Lund UniversityBox 11822100LundSweden divison of chemical physics Lund UniversityBox 12422100LundSweden Toyota Technological Institute NagoyaAichi 468-8511Japan

Nanowires require surface passivation due to their inherent large surface to volume ratio. We investigate the effect of embedding InP nanowires in different oxides with respect to surface passivation by use of electron beam induced current measurements enabled by a nanoprobe based system inside a scanning electron microscope. The measurements reveal remote doping due to fixed charge carriers in the passivating PO_(x)/Al_(2)O_(3) shell in contrast to results using SiO_(x). We used time-resolved photoluminescence to characterize the lifetime of charge carriers to evaluate the success of surface passivation. In addition, spatially resolved internal quantum efficiency simulations support and correlate the two applied techniques. We find that atomic-layer deposited PO_(x)/Al_(2)O_(3) has the potential to passivate the surface of InP nanowires, but at the cost of inducing a field-effect on the nanowires, altering their electrostatic potential profile. The results show the importance of using complementary techniques to correctly evaluate and interpret processing related effects for optimization of nanowire-based optoelectronic devices.

关键词： InP nanowires oxides MOVPE electron beam induced current(EBIC) time-resolved photoluminescence(TRPL) field-effect

Fabrication of carbon-supported Al2O3 nanoparticles via spontaneous cross-linking to enhance selective hydrogenation of furfural

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Journal of Energy Chemistry 2025年第01期 612-620页

作者： Weiwei Yu Xinbao Zhang Hongyu Chen Yanan Wang Shaoguo Li Fucun Chen Zhenni Liu Xiujie Li Xiangxue Zhu State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Selective hydrogenation of furfural to furfuryl alcohol is a great challenge in the hydrogenation field due to thermodynamic preference for hydrogenation of C=C over C=***,a novel Al2O3/C-u hybrid catalyst,composed of N-modified dendritic carbon networks supporting Al2O3nanoparticles,was successfully prepared via carbonizing the freeze-dried gel from spontaneous cross-linking of alginate,Al3+and *** obtained carbon-supported Al2O3hybrid catalyst has a high ratio （31%） of Al species in pentahedral-coordinated *** introduction of urea enhances the surface N content,the ratio of pyrrolic N,and specific surface area of catalyst,leading to improved adsorption capacity of C=O and the accessibility of active *** the furfural hydrogenation reaction with isopropyl alcohol as hydrogen donor,Al2O3/C-u catalyst achieved a 90%conversion of furfural with 98.0% selectivity to furfuryl alcohol,outperforming that of commercial γ-***,Al2O3/C-u demonstrates excellent catalytic stability in the recycling tests attributed to the synergistic effect of abundant weak Lewis acid sites and the anchoring effect of the carbon network on *** work provides an innovative and facile strategy for fabrication of carbon-supported Al2O3hybrid catalysts with rich AlVspecies,serving as a high selective hydrogenation catalyst through MPV reaction route.

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Low-cost and fluoride-free synthesis of MFI zeolite nanosheets with enhanced stability for benzene alkylation with ethanol

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Journal of Energy Chemistry 2025年第1期 458-468页

作者： Peng Zhu Cun Liu Yiren Yu Guoshu Gao Yumeng Zhao Xiongfu Zhang Guodong Liu Guohui Yang State Key Laboratory of Fine chemicals School of Chemical Engineering Dalian University of Technology State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Zeolite nanosheets with a short b-axis thickness are highly desirable in lots of catalytic reactions due to their reduced diffusion resistance. Nevertheless, conventional synthesis methods usually require expensive structure-directing agents(SDAs), pricey raw materials, and eco-unfriendly fluorine-containing additives. Here, we contributed a cost-effective and fluoride-free synthesis method for synthesizing high-quality MFI zeolite nanosheets through a Silicalite-1(Sil-1) seed suspension and urea cooperative strategy, only with inexpensive colloidal silica as the Si source. Our approach was effective for synthesizing both Sil-1 and aluminum-containing ZSM-5 nanosheets. By optimizing key synthesis parameters,including seed aging time, seed quantity, and urea concentration, we achieved precise control over the crystal face aspect ratio and b-axis thickness. We also revealed a non-classical oriented nanosheet growth mechanism, where Sil-1 seeds induced the formation of quasi-ordered precursor particles, and the(010)crystal planes of these particles facilitated urea adsorption, thereby promoting c-axis-oriented *** obtained ZSM-5 nanosheets exhibited exceptional catalytic performance in the benzene alkylation with ethanol, maintaining stability for over 500 h, which is 5 times longer than traditional ZSM-5 catalysts. Furthermore, large-scale production of ZSM-5 nanosheets was successfully carried out in a 3 L highpressure autoclave, yielding samples consistent with those from laboratory-scale synthesis. This work marks a significant step forward in the sustainable and efficient production of MFI nanosheets using inexpensive and environmentally friendly raw materials, offering the broad applicability in catalysis.

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Effects of Cerium Oxide on Ni/Al_2O_3 Catalysts for Decomposition of CH_4 and C_2H_4

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Journal of Rare Earths 2003年第4期21卷 427-429页

作者：杨咏来李文钊徐恒泳 Dalian Institute of chemical physics

Characteristics of carbon deposition of CH 4 and C 2H 4 decomposition over supported Ni and Ni Ce catalysts were studied by using a pulse reaction as well as BET, TPR, XPS and hydrogen chemisorption techniques. It is found that there is a metal semiconductor interaction (MScI) in the Ni Ce catalyst, and the effect of MScI on the carbon deposition of CH 4 decomposition is opposite to that of C 2H 4. A novel model of carbon deposition of CH 4 or C 2H 4 decomposition was proposed.

关键词： catalytic chemistry Ni/Al 2O 3 catalyst cerium oxide methane ethylene decomposition rare earths

ANALYSIS OF THE REMOVAL OF H_2S WITH IMPREGNATED ACTIVATED CARBON

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Chinese Journal of chemical Engineering 1997年第2期5卷 5-12页

作者：谭小耀吴迪镛袁权 Dalian Institute of chemical physics Academia Sinica

A general mathematical model with its governing equations in dimensionless forms has beendeveloped to describe the removal of hydrogen sulfide with impregnated activated *** relationship between the sulfur capacity and the reaction time in a single carbon pellet isobtained,and criterion to ascertain the rate controlling step of the process can then be *** meantime,the choice of the appropriate oxygen concentration and the principle to be followedare also described.

关键词： desulfurization impregnated activated carbon hydrogen sulfide

Label-free detection of single nanoparticles and biological molecules using microtoroid optical resonators

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Light(Science & Applications) 2016年第1期5卷 863-868页

作者： Judith Su Alexander FG Goldberg Brian M Stoltz Division of Biology and Biological Engineering California Institute of TechnologyPasadenaCAUSA divison of Chemistry and chemical Engineering California Institute of TechnologyPasadenaCAUSA

Single-molecule detection is one of the fundamental challenges of modern *** experiments often use labels that can be expensive,difficult to produce,and for small analytes,might perturb the molecular events being *** size plays an important role in determining *** we use laser-frequency locking in the context of sensing to improve the signal-to-noise ratio of microtoroid optical resonators to the extent that single nanoparticles 2.5 nm in radius,and 15.5 kDa molecules are detected in aqueous solution,thereby bringing these detectors to the size limits needed for detecting the key macromolecules of the *** results,covering several orders of magnitude of particle radius(100 nm to 2 nm),agree with the‘reactive’model prediction for the frequency shift of the resonator upon particle *** confirms that the main contribution of the frequency shift for the resonator upon particle binding is an increase in the effective path length due to part of the evanescent field coupling into the adsorbed *** anticipate that our results will enable many applications,including more sensitive medical diagnostics and fundamental studies of single receptor–ligand and protein–protein interactions in real time.

关键词： biosensing frequency locking label-free microtoroid single molecule

A SLOW RELAXATION MODE OF POLYMER CHAINS IN A SEMIDILUTE SOLUTION

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Chinese Journal of Polymer Science 2008年第4期26卷 465-473页

作者：张广照 Department of chemical physics University of Science and Technology of China

Dust-free semidilute and concentrated polystyrene(PS)solutions in different solvents were prepared by slow evaporation and in situ anionic polymerization,which removes the effects of troublesome artifacts such as dust contamination and concentration *** dynamics was reexamined by a combination of static and dynamic laser light *** benzene and toluene(good solvents for PS),only one fast diffusive mode of polymer chains can be observed when the concentration(c)is up to 20%,which is attribut...

关键词： Semidilute Anionic polymerization Laser light scattering Blob Correlation length Slow mode

Catalytic conversion of glucose to small polyols over a binary catalyst of vanadium modified beta zeolite and Ru/C

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Journal of Energy Chemistry 2019年第7期28卷 88-95页

作者： Joby Sebastian Mingyuan Zheng Xinsheng Li Jifeng Pang Chan Wang Tao Zhang Dalian Institute of chemical physics Chinese Academy of Sciences

Catalytic conversion of glucose, the most abundant carbohydrate, to chemicals of petroleum origin has great desirability in terms of sustainability and industrial implementation. In this work, we attempted to exploit the vanadium-based catalysts with high retro-aldol condensation(RAC) activity for the synthesis of small polyols from glucose. Vanadium species incorporated or anchored beta zeolites were found to work effectively in synergy with 1 Ru/AC to produce hydroxyacetone(HA) as the major product(34%)in a semi-continuously stirred tank reactor under 5% glucose concentration. Catalyst characterization by UV-vis and Raman spectral analysis revealed vanadium species mainly stayed in the incorporated form(tetrahedral) at 0.5% of loading and in the supported form(octahedral) at higher loadings up to 8%. Pyridine infrared spectra and temperature programmed desorption of NH3 revealed weak Lewis acid sites in dominance. Vanadium species in the catalysts displayed multiple catalytic roles(isomerization and RAC reaction, and synergism with the hydrogenation catalyst) in the synthesis of HA from glucose. Structureactivity correlation pointed out that the catalytic activity of vanadium species is not dependent on it coordination status, nevertheless, the adjacent vanadium atoms could possibly improve the isomerization rate over the RAC rate in favor of high yield of HA. The catalyst system is recyclable to at least five times without any considerable loss in its activity and structural integrity. The results presented here provide a promising route for the sustainable production of HA and polyols from carbohydrates by using a highly selective vanadium catalyst.

关键词： Vanadium Glucose Retro-aldol condensation Polyols Hydroxyacetone