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91.
Research on NOx treatment is extensive in recent years due to growing environmental awareness. Selec- tive catalytic reduction (SCR) of NOx, as a proven technology, offers higher NOx control efficiency than many other NOx treatment methods. The present work reviews the recent development of SCR reactor technologies. Firstly, catalysts and mechanism of different SCRs were briefly summarized. Different SCR reactors, e.g. structured reactor, fluidized bed reactor and moving bed reactor, were then discussed. As a more advanced technology, multifunctional reactors were also developed for SCR process and could be divided into two categories: decoupled adsorption-reaction process and combined SCR system. The mechanism and properties of these processes were discussed in detail. Some recommendations were given for the future work in SCR reactor design. SCR reactor technology for emerging energy processes was also addressed, such as oxyfuel combustion and biofuel conversion processes, which put forward new requirements for SCR technologies and also open new opportunities for advanced design of SCR reactors. 相似文献
92.
Guiqiang Cao Zhikang Wang Da Bi Prof. Jing Zheng Prof. Qingxue Lai Prof. Yanyu Liang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(45):10314-10320
Lithium-sulfur batteries have been considered as potential electrochemical energy-storage devices owing to their satisfactory theoretical energy density. Nonetheless, the inferior conversion efficiency of polysulfides in essence leads to fast capacity decay during the discharge/charge cycle. In this work, it is successfully demonstrated that the conversion efficiency of lithium polysulfides is remarkably enhanced by employing a well-distributed atomic-scale Fe-based catalyst immobilized on nitrogen-doped graphene (Fe@NG) as a coating of separator in lithium-sulfur batteries. The quantitative electrocatalytic efficiency of the conversion of lithium polysulfides is determined through cyclic voltammetry. It is also proven that the Fe-NX configuration with highly catalytic activity is quite beneficial for the conversion of lithium polysulfides. In addition, the adsorption and permeation experiments distinctly indicate that the strong anchoring effect, originated from the charge redistribution of N doping into the graphene matrix, inhibits the movement of lithium polysulfides. Thanks to these advantages, if the as-prepared Fe@NG catalyst is combined with polypropylene and applied as a separator (Fe@NG/PP) in Li-S batteries, a high initial capacity (1616 mA h g−1 at 0.1 C), excellent capacity retention (93 % at 0.2 C, 70 % at 2 C), and superb rate performance (820 mA h g−1 at 2 C) are achieved. 相似文献
93.
Let E?R be an interval. By studying an admissible family of branching mechanisms{ψt,t ∈E} introduced in Li [Ann. Probab., 42, 41-79(2014)], we construct a decreasing Levy-CRT-valued process {Tt, t ∈ E} by pruning Lévy trees accordingly such that for each t ∈E, Tt is a ψt-Lévy tree. We also obtain an analogous process {Tt*,t ∈E} by pruning a critical Levy tree conditioned to be infinite. Under a regular condition on the admissible family of branching mechanisms, we show that the law of {Tt,t ∈E} at the ascension time A := inf{t ∈E;Tt is finite} can be represented by{Tt*,t∈E}.The results generalize those studied in Abraham and Delmas [Ann. Probab., 40, 1167-1211(2012)]. 相似文献
94.
Xiaoxiao Xu Prof. Caihong Fang Ting Bi Zhiqing Cui Guili Zhao Xiaomin Jiang Jinwu Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(47):10787-10794
Plasmonic nanostructures with large absorption areas under resonant excitation have been utilized extensively in photon-assisted applications. In this work, dodecahedral Au nanobowls were first prepared by an easy and template-free method only through the introduction of H2PtCl6 and I− during the growth procedure. The Au nanobowls show electron-field enhancement due to the high curvature of the bowl edge, the open region, and dodecahedral morphology. Au/Pt nanobowls, which couple plasmonic Au and catalytic Pt, were then constructed as plasmonic electrocatalysts for methanol oxidation. The mass activity reached 497.6 mA mg−1 under visible-light illumination, which is 1.9 times that measured in the dark. Simultaneously, the electrocatalytic stability is also greatly improved under light excitation. The enhanced properties of the plasmonic Au/Pt electrocatalysts are ascribed to the synergistic effect of the plasmon-enhanced photothermal and hot-carrier effects on the basis of experimental investigations. This work thus offers an effective methodology to construct efficient plasmonic electrocatalysts for fuel cells. 相似文献
95.
Prof. Caihong Fang Guili Zhao Zijun Zhang Qian Ding Nan Yu Zhiqing Cui Ting Bi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7351-7358
Multifunctional metal nanostructures with a hollow feature, especially for nanoframes, are highly attractive owing to their high surface-to-volume ratios. However, pre-grown metal nanocrystals are always involved during the preparation procedure, and a synthetic strategy without the use of a pre-grown template is still a challenge. In this article, a template-free strategy is reported for the preparation of novel AuPt alloy nanoframes through simply mixing HAuCl4 and H2PtCl6 under mild conditions. The alloy nanostructures show a bipyramid-frame hollow architecture with the existence of only the ten ridges and absence of their side faces. This is the first report of bipyramid-like nanoframes and a template-free method under mild conditions. This configuration merges the plasmonic features of Au and highly active catalytic sites of Pt in a single nanostructure, making it an ideal multifunctional platform for catalyzing and monitoring the catalytic reaction in real time. The superior catalytic activity is demonstrated by using the reduction of nitrobenzene to the corresponding aminobenzene as a model reaction. More importantly, the AuPt nanoframes can track the reduction process on the basis of the SERS signals of the reactants, intermediates, and products, which helps to reveal the reaction mechanism. In addition, the AuPt nanoframes show much higher electrocatalytic properties toward the methanol oxidation reaction than commercial Pt/C electrocatalysts. 相似文献
96.
Lulu Wang Jinmiao Wang Chuanbin Fan Caifeng Bi Xia Zhang Dongmei Zhang Mei Wang Yuhua Fan 《应用有机金属化学》2020,34(9):e5767
Two novel Co (II)- coordination polymers (CPs) based on 2,5-bis(4-carboxylpheny)-1,3,4-oxadiazole (bcpo), namely [Co/(bcpo)0.5(tib)(H2O)2]n (1) and [Co (bcpo)0.5(bidpe)(H2O)2]n (2) (tib = 1,3,5-tirs(1-imidazolyl)benzene, bidpe = 4,4′-bis (imidazolyl)diphenyl ether) have been synthesized under solvothermal conditions and characterized by powder X-ray diffraction (PXRD), single crystal X-ray diffraction, photochemistry as well as electrochemistry. The investigation of the photo-degradation methyl blue and methyl violet (MB, MV) properties of CPs 1–2 demonstrates that CP 1 shows great performance for the degradation of MB, and CP 2 could efficiently degrade MB/MV. Meanwhile, the possible photo-degradation mechanism has been proposed and explored. Simultaneously, electrochemistry studies show that both CPs 1 and 2 can catalyze water oxidation under an alkaline condition at the potential around 1.20 V vs. NHE with relatively low overpotential of 330–510 mV vs. NHE. 相似文献
97.
98.
Mixed matrix materials, containing poly(dimethylsiloxane), phosphine oxide-based polyimide, and zeolite Y were prepared by means of blending hybridisation. The thermal stability of the materials and the hydrophobic properties were enhanced. The decrease in the glass transition temperature of the materials with the increase in poly(dimethylsiloxane) content supported the polymer-chain flexibility. The pristine polyimide and the zeolite-filled polyimide exhibited the highest transparency. Fourier transform infrared (FTIR) spectroscopy confirmed that the increase in the amount of the lowest molecular mass poly(dimethylsiloxane) ingredient indicated strong alkyl and Si-O-Si stretching modes, whilst the alkyl and Si-O-Si stretching intensity decreased in the presence of the highest amount of and the highest molecular mass poly(dimethylsiloxane). The hydrophobic poly(dimethylsiloxane) moiety created an inverse relationship between the porosity of the materials (surface roughness) and the hydrophilicity. The nanocrystallite domain, identified by X-ray diffraction analysis (XRD) and possessing an exotherm crystallisation peak, occurred in the lowest amount of poly(dimethylsiloxane) with the highest molecular mass-based hybrid material. The nanocrystallite enhanced the storage modulus as determined by the dynamic mechanical analyser (DMA). The nanocrystalline formation resulted in a slight increase in the alkyl stretching and the Si-O-Si stretching of the lowest amount of and the highest molecular mass poly(dimethylsiloxane)-containing material over those of the lowest molecular mass poly(dimethylsiloxane) in the same amounts of material involved. 相似文献
99.
Goto J. Oshima M. Sugawara M. Yamaguchi Y. Bi C. Bamba S. Morimoto T. 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(3):1707-1714
Charged particle activation analysis (CPAA) is a rapid method with high accuracy which can analyze multi-elements simultaneously. Since multiple γ-ray detection method is expected to improve the detection efficiency and the signal-to-noise ratio, we study what design of the γ-ray detector array is the most suitable for CPAA. We take up four design candidates and investigated the responses by the radiation simulation code Geant 4. From the results, we have deduced the best design with 5 germanium detectors in close geometry. By inspecting the sensitivity in CPAA, the method is proved to be useful and applicable to 116 nuclides.
相似文献100.