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1.
Ping Zhang Wei-guo Pan Rui-tang Guo Shu-ming Liu Ming-yuan Li Ling Qin Xiao-qing Pan Xia-feng Ye 《Chemical Papers》2018,72(6):1347-1361
Mn–TiO2 catalysts were utilized as an ozonation catalyst for the first time to study the simultaneous catalytic ozonation of Hg0 and NO at low flue gas temperatures. BET, SEM–EDS, XRD, XPS, H2-TPR, NO x -TPD and Hg0-TPD were used to characterize the catalysts. The Mn–TiO2 catalyst, in which the molar content of metal Mn was 60%, exhibited the best catalytic activities of Hg0 and NO oxidation, compared with other Mn–TiO2 catalysts. It was found that within the range of experiment, the catalytic ozonation efficiency of Hg0 and NO was higher than that of ozonation or catalytic oxidation. The results also showed that the presence of NO gas inhibited the catalytic ozonation of elemental mercury, and the inhibition was enhanced with the NO inlet concentration, while few elemental mercury molecules did promote the catalytic ozonation of NO. The addition of H2O vapor promoted the catalytic ozonation of Hg0 and NO. In addition, 0.6Mn–TiO2 catalyst demonstrated a good TOS and cyclic stability. The catalytic ozonation of NO and Hg0 on Mn–TiO2 catalyst likely followed the Langmuir–Hinshelwood mechanism, where the hydroxyl radicals reacted with adjacently adsorbed NO molecules and elemental mercury on catalyst surface. 相似文献
2.
Application of the Fe3O4@1,10‐phenanthroline‐5,6‐diol@Mn nano‐catalyst for the green synthesis of tetrazoles and its biological performance
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Davood Habibi Somayyeh Heydari Antonio Gil Mina Afsharfarnia Alireza Faraji Roya Karamian Mostafa Asadbegy 《应用有机金属化学》2018,32(2)
The Fe3O4 magnetic particles were modified with 1,10‐phenanthroline‐5,6‐diol (Phen) and the related Mn complex (Fe3O4@Phen@Mn) synthesized as a heterogeneous catalyst to be used for the one‐pot three‐component synthesis of various tetrazoles. The catalysts were characterized by several methods, such as the elemental analysis, FT‐IR, X‐ray powder diffraction, dispersive X‐ray spectroscopy, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, thermogravimetric‐differential thermal analysis, vibrating sample magnetometer and X‐ray photoelectron spectroscopy. In addition, the antioxidant and antibacterial activities of the catalyst and its Phen ligand were in vitro screened with 2,2‐diphenyl‐1‐picrylhydrazyl by free radical scavenging methods. Results showed that the synthesized compounds possess strong antioxidant activity (IC50; 0.172 ± 0.005 mg ml?1) as well as a good antibacterial potential in comparison to standards. 相似文献
3.
The development of green and efficient catalysts for peroxymonosulfate (PMS) activation and organic pollutants degradation has received widespread attention. In this study, the hybrid CaCO3/OMS‐2 catalysts were prepared by a simple precipitation approach and characterized by X‐ray powder diffraction, N2 adsorption–desorption, scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy and cyclic voltammetry. It was found that deposition of CaCO3 on OMS‐2 surface can weaken the Mn‐O bond by formation of Ca‐O‐Mn bond. The interactions between CaCO3 and OMS‐2 significantly enhanced Acid Orange 7 degradation in the presence of PMS with a pseudo‐first‐order kinetic constant of 0.21 min?1, which was much higher than those of OMS‐2 (0.026 min?1) and CaCO3 (0.021 min?1). The CaCO3/OMS catalysts were also much more efficient than other reported OMS‐2 hybrid catalysts, and could be performed over a wide solution pH and for other organic dyes degradation. Sulfate and hydroxyl radicals were formed from the oxidation of low valent manganese species by PMS as the active species in the system. This study can provide a simple method for the design of efficient manganese‐based hybrids for wastewater remediation via PMS activation. 相似文献
4.
Rafael Stieler Davi F. Back Bárbara Tirloni Robert A. Burrow Prof. Dr. Ernesto S. Lang 《无机化学与普通化学杂志》2012,638(10):1501-1503
Two synthetic routes to prepare [Hg3(O2SePh)(SePh)5]n and its structural characterization are presented in this paper. This compound results either from the partial oxidation of mercury phenylselenolate clusters or from a mixture of its components with defined stoichiometry. This compound was observed in almost all of our reactions as a by‐product, during the development of the synthesis of new mercury selenolate clusters. It was now characterized by single‐crystal X‐ray diffractometry, elemental analysis, and infrared spectroscopy. 相似文献
5.
. The complex Hg4(L2)2(NO3)4 ( 1 ) (L2 = morpholin‐4‐ylpyridin‐2‐ylmethyleneamine) has been synthesized and characterized by CHN analysis, IR, and UV/Vis spectroscopy. The crystal structure of 1 was determined using single‐crystal X‐ray diffraction. The crystal structure of 1 contains four mercury atoms, four nitrate anions (two terminal and two bridge ones) and two L2 ligand molecules. A chair shape, six‐membered ring is formed with the sequence OHgHgOHgHg built from Hg–Hg dumbbells and oxygen atoms from the nitrate co‐ligands. In the crystal structure, the asymmetric unit of the compound is built up by one‐half of the molecule. It contains the Hg22+ moiety with a mercury–mercury bonded core, in which one diimine ligand is coordinated to one of the mercury atoms. The nitrate anions act as anisobidentate and bidentate ligands. 相似文献
6.
A new mercury(II) complex of 1,2‐bis(4‐pyridyle)ethene (bpe) with anionic acetate and thiocyanate ligands has been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The single crystal X‐ray analysis shows that the complex is a two‐dimensional polymer with simultaneously bridging 1,2‐bis(4‐pyridyle)ethane, acetate and thiocyanate ligands and basic repeating dimeric [Hg2(μ‐bpe)(μ‐OAc)2(μ‐SCN)2] units. The two‐dimensional system forms a three‐dimensional network by packing via π‐π stacking interactions. 相似文献
7.
Two well‐ordered 2D ‐ hexagonal cerium (IV) and erbium (III) embedded functionalized mesoporous MCM ‐ 41(MCM‐41@Serine/Ce and MCM ‐ 41@Serine/Er) have been developed via functionalization of mesoporous MCM ‐ 41. The surface modification method has been used in the preparation of serine‐grafted MCM ‐ 41 and led to the development of MCM‐41@Serine. The reaction of MCM‐41@Serine with Ce (NH4)2(NO3)6·2H2O or ErCl3·6H2O in ethanol under reflux led to the organization of MCM‐41@Serine/Ce and MCM‐41@Serine/Er catalysts. The structures of these catalysts were determined using scanning electron microscopy, mapping, energy‐dispersive X‐ray spectroscopy, Fourier transform‐infrared, thermogravimetric analysis, X‐ray diffraction, inductively coupled plasma, and Brunauer–Emmett–Teller analysis. These MCM‐41@Serine/Ce and MCM‐41@Serine/Er catalysts show outstanding catalytic performance in sulfides oxidation and synthesis of 5‐substituted tetrazoles. These catalysts can be recycled for seven repeated reaction runs without showing a considerable decrease in catalytic performance. 相似文献
8.
A new one‐dimensional double‐chain HgII coordination polymer containing the ligand 3,5‐bis(4‐pyridyl)‐4‐amino‐1,2,4‐triazole (bpatrz) and thiocyanate anions, namely, {[Hg2(μ‐bpatrz)(μ‐SCN)2(SCN)2] · MeOH}n ( 1 ), has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 displays bright blue luminescence with emission maxima around 370 and 440 nm in solution and the solid state, respectively. Uptake and release of MeOH by 1 were investigated by powder X‐ray diffraction, thermogravimetric analysis, elemental analysis, and IR and NMR spectroscopy. 相似文献
9.
《Surface and interface analysis : SIA》2018,50(2):171-179
TiO2 thin films with various Mo concentrations have been deposited on glass and n‐type silicon (100) substrates by this radio‐frequency (RF) reactive magnetron sputtering at 400°C substrate temperature. The crystal structure, surface morphology, composition, and elemental oxidation states of the films have been analyzed by using X‐ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy, respectively. Ultraviolet‐visible spectroscopy has been used to investigate the degradation, transmittance, and absorption properties of doped and undoped TiO2 films. The photocatalytic degradation activity of the films was evaluated by using methylene blue under a light intensity of 100 mW cm−2. The X‐ray diffraction patterns show the presence of anatase phase of TiO2 in the developed films. X‐ray photoelectron spectroscopy studies have confirmed that Mo is present only as Mo6+ ions in all films. The Mo/TiO2 band gap decreases from ~3.3 to 3.1 eV with increasing Mo dopant concentrations. Dye degradation of ~60% is observed in Mo/TiO2 samples, which is much higher than that of pure TiO2. 相似文献
10.
Visualization of Heterogeneous Oxygen Storage Behavior in Platinum‐Supported Cerium‐Zirconium Oxide Three‐Way Catalyst Particles by Hard X‐ray Spectro‐Ptychography
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Makoto Hirose Dr. Nozomu Ishiguro Kei Shimomura Dr. Nicolas Burdet Dr. Hirosuke Matsui Prof. Dr. Mizuki Tada Prof. Dr. Yukio Takahashi 《Angewandte Chemie (International ed. in English)》2018,57(6):1474-1479
The cerium density and valence in micrometer‐size platinum‐supported cerium–zirconium oxide Pt/Ce2Zr2Ox (x=7–8) three‐way catalyst particles were successfully mapped by hard X‐ray spectro‐ptychography (ptychographic‐X‐ray absorption fine structure, XAFS). The analysis of correlation between the Ce density and valence in ptychographic‐XAFS images suggested the existence of several oxidation behaviors in the oxygen storage process in the Ce2Zr2Ox particles. Ptychographic‐XAFS will open up the nanoscale chemical imaging and structural analysis of heterogeneous catalysts. 相似文献
11.
With various contents, Mn was introduced into carbon nanotubes (CNTs) supported cobalt catalysts and the obtained Mn‐Co/CNTs catalysts were investigated for CO hydrogenation to light alkenes and characterized by N2 adsorption, X‐ray diffraction (XRD), X‐ray photoelectron spectra (XPS), H2 temperature programmed reduction (TPR), CO temperature programmed desorption (TPD) and transmission electron microscope (TEM). The results indicate that the addition of a small amount of Mn (0.3 wt%) to CNTs‐supported Co catalyst significantly increased the selectivity of C2–C4 olefins and decreased the selectivity of CH4. However, with further addition of Mn to the cobalt catalysts, the CH4 selectivity decreased obviously along with the increase of the C5+ selectivity. Compared with the unpromoted catalysts, the Mn‐promoted cobalt catalysts increased the C2?–C4?/C20–C40 molar ratio. 相似文献
12.
Revealing the Dynamic Structure of Complex Solid Catalysts Using Modulated Excitation X‐ray Diffraction
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Dr. Davide Ferri Dr. Mark A. Newton Dr. Marco Di Michiel Dr. Gian Luca Chiarello Dr. Songhak Yoon Dr. Ye Lu Dr. Jérôme Andrieux 《Angewandte Chemie (International ed. in English)》2014,53(34):8890-8894
X‐ray diffraction (XRD) is typically silent towards information on low loadings of precious metals on solid catalysts because of their finely dispersed nature. When combined with a concentration modulation approach, time‐resolved high‐energy XRD is able to provide the detailed redox dynamics of palladium nanoparticles with a diameter of 2 nm in 2 wt % Pd/CZ (CZ=ceria–zirconia), which is a difficult sample for extended X‐ray absorption fine structure (EXAFS) measurements because of the cerium component. The temporal evolution of the Pd(111) and Ce(111) reflections together with surface information from synchronous diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements reveals that Ce maintains Pd oxidized in the CO pulse, whereas reduction is detected at the beginning of the O2 pulse. Oxygen is likely transferred from Pd to Ce3+ before the onset of Pd re‐oxidation. In this context, adsorbed carbonates appear to be the rate‐limiting species for re‐oxidation. 相似文献
13.
Reverse Micelle Synthesis of Colloidal Nickel–Manganese Layered Double Hydroxide Nanosheets and Their Pseudocapacitive Properties
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Hwansu Sim Changshin Jo Prof. Taekyung Yu Eunho Lim Prof. Songhun Yoon Prof. Jung Heon Lee Prof. Jibeom Yoo Prof. Jinwoo Lee Prof. Byungkwon Lim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14880-14884
Colloidal nanosheets of nickel–manganese layered double hydroxides (LDHs) have been synthesized in high yields through a facile reverse micelle method with xylene as an oil phase and oleylamine as a surfactant. Electron microscopy studies of the product revealed the formation of colloidal nanoplatelets with sizes of 50–150 nm, and X‐ray diffraction, energy dispersive X‐ray spectroscopy, and X‐ray photoelectron spectroscopy studies showed that the Ni–Mn LDH nanosheets had a hydrotalcite‐like structure with a formula of [Ni3Mn(OH)8](Cl?) ? n H2O. We found that the presence of both Ni and Mn precursors was required for the growth of Ni‐Mn LDH nanosheets. As pseudocapacitors, the Ni–Mn LDH nanosheets exhibited much higher specific capacitance than unitary nickel hydroxides and manganese oxides. 相似文献
14.
Preparation,characterization and catalytic activity studies of organoruthenium‐supported polyoxotungstates on SBA‐15
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Organoruthenium‐supported polyoxometalates [(RuC6H6)XW9O34]7? (XWRu; X = As, P) were selected as samples to study their catalytic activities towards the solvent‐free oxidation of n‐hexadecane. First of all, the XWRu were deposited on 3‐aminopropyltriethoxysilane‐modified SBA‐15 to prepare solid catalysts, which were characterized using powder X‐ray diffraction, nitrogen adsorption measurements, Fourier transform infrared reflectance spectroscopy and X‐ray photoelectron spectroscopy. Subsequently, their catalytic performances and stabilities were assessed through the oxidation of n‐hexadecane using air as the oxygen source without any additives and solvents, and the influences of the loading amount, catalyst amount, reaction time and reaction temperature on the catalytic activities were investigated. The results indicated the influence of the central heteroatoms X of XWRu on the catalytic activities. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
Honghu Li Shengkai Wang Xu Wang Nian Tang Siwei Pan Jiangjun Hu 《Chemical Papers》2017,71(9):1569-1578
The Co–Mn/Ti–Ce catalyst prepared by sol–gel and impregnation method was evaluated for catalytic oxidation of Hg0 in the simulated flue gas compared with Co/TiO2 and Co–Mn/TiO2. The results showed that Co–Mn/Ti–Ce catalyst exhibited higher catalytic activity (around 93% Hg0 removal efficiency in the temperature of 150 °C with 6% O2, 400 ppm NO, 200 ppm SO2 and 3% H2O) than Co/TiO2 and Co–Mn/TiO2. Based on the characterization results of N2 adsorption–desorption, XRD, UV–Vis, XPS, H2-TPR and Hg-TPD, it could be concluded that the lower band gap, better reducibility and mercury adsorption capability and the presence of Co3+/Co2+, Mn4+/Mn3+ and Ce4+/Ce3+ redox couples as well as surface oxygen species contributed to the excellent Hg0 oxidation removal performance. In addition, well dispersion of active components and a synergetic effect among Co, Mn and Ce species might improve the activity further. A Mars–Maessen mechanism is thought to be involved in the Hg0 oxidation. The lattice oxygen derived from MnO x or CoO x would react with adsorbed Hg0 to form HgO and the consumption of lattice oxygen could be replenished by O2. For Co–Mn/Ti–Ce, MnO x?1 could be alternatively reoxidized by the lattice oxygen derived from adjacent CoO x and CeO x which is beneficial to the Hg0 oxidation. 相似文献
16.
Dr. Anna B. Kroner Dr. Mark A. Newton Prof. Dr. Moniek Tromp Prof. Andrea E. Russell Prof. Andrew J. Dent Prof. John Evans 《Chemphyschem》2013,14(15):3606-3617
The effects of the addition of ceria and zirconia on the structural properties of supported rhodium catalysts (1.6 and 4 wt % Rh/γ‐Al2O3) are studied. Ceria and zirconia are deposited by using two preparation methods. Method I involves the deposition of ceria on γ‐Al2O3 from Ce(acac)3, and the rhodium metal is subsequently added, whereas method II is based on a controlled surface reaction technique, that is, the decomposition of metal–organic M(acac)x (in which M=Ce, x=3 and M=Zr, x=4) on Rh/γ‐Al2O3. The structures of the prepared catalyst materials are characterized ex situ by using N2 physisorption, transmission electron microscopy, high‐angle annular dark‐field scanning transmission election microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy (XPS), and X‐ray absorption fine structure spectroscopy (XAFS). All supported rhodium systems readily oxidize in air at room temperature. By using ceriated and zirconiated precursors, a larger rhodium‐based metallic core fraction is obtained in comparison to the undoped rhodium catalysts, suggesting that ceria and zirconia protect the rhodium particles against extensive oxidation. XPS results indicate that after the calcination and reduction treatments, a small amount of chlorine is retained on the support of all rhodium catalysts. EXAFS analysis shows significant Rh? Cl interactions for Rh/Al2O3 and Rh/CeOx/Al2O3 (method I) catalysts. After reaction with H2/He in situ, for series of samples with 1.6 wt % Rh, the EXAFS first shell analysis affords a mean size of approximately 30 atoms. A broader spread is evident with a 4 wt % rhodium loading (ca. 30–110 atoms), with the incorporation of zirconium providing the largest particle sizes. 相似文献
17.
The first montmorillonite‐supported surface single‐structure titanium complex: synthesis,characterization and catalytic activity in alkene epoxidation
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Wei Xu Bo Yu Huaming Sun Jindou Yang Ying Zhang Zhenhua Wang Xi Chen Guofang Zhang Ziwei Gao 《Surface and interface analysis : SIA》2015,47(3):308-314
A well‐defined single‐site titanium‐modified montmorillonite (MMT) with only one geometric construction ((?SiO)3–Ti–NMe2) was obtained in moderate conditions. Reaction of tetrakis(dimethylamido)titanium with hydroxylated MMT was conducted by surface organometallic chemistry technique, and the surface structure was characterized by in situ Fourier transform infrared spectroscopy, 13C cross polarization magic angle spinning nuclear magnetic resonance, X‐ray photoelectron spectroscopy, extended X‐ray absorption fine structure, and elemental analysis. The catalytic activity in alkene epoxidation was evaluated, and the results revealed that the steric hindrance of the substances is responsible for the catalytic activity of the MMT‐supported titanium complex but to the characteristic restricted layer‐like structure of the MMT. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
18.
《应用有机金属化学》2017,31(12)
For the first time, iron oxide on carbon aerogel, amine functionalized carbon nanotube, black carbon and carboxylic acid functionalized carbon nanotube in the presence of H2O2 was reported as an efficient and stable catalyst for the selective oxidation of sulfides and alcohols. The catalysts were characterized by scanning electron microscopy, energy‐dispersive spectroscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy and atomic absorption spectroscopy. In the next step, catalytic reactivity toward sulfide to sulfoxide and alcohol to aldehyde/ketone oxidation in the presence of H2O2 was studied and discussed. 相似文献
19.
Huan‐Ling Wang Rong Li Yun‐Feng Zheng Hang‐Ning Chen Jun Jin Fu‐Shan Wang Jian‐Tai Ma 《Helvetica chimica acta》2007,90(9):1837-1847
Bismuth (Bi)‐containing SBA‐15 mesoporous silica catalysts, Bi/SBA‐15, with different Bi loadings were synthesized by a direct hydrothermal method. The materials were characterized in detail by various techniques. Powder‐X‐ray‐diffraction (PXRD), N2‐adsorption/desorption, and transmission‐electron‐microscopic (TEM) analyses revealed that the well‐ordered hexagonal structure of SBA‐15 is maintained after Bi incorporation. Diffuse‐reflectance UV/VIS, Raman, and X‐ray photoelectron spectroscopy (XPS) showed that the incorporated Bi‐atoms are highly dispersed, most of them entering the internal surface of SBA‐15. The new, very stable catalysts were found to be highly efficient for the oxidation of cyclohexane in a solvent‐free system, molecular oxygen (O2) being used as oxidant. 相似文献
20.
Xiang Li Annette‐Enrica Surkus Jabor Rabeah Muhammad Anwar Sarim Dastigir Henrik Junge Angelika Brückner Matthias Beller 《Angewandte Chemie (International ed. in English)》2020,59(37):15849-15854
Metal–organic framework (MOF)‐derived Co‐N‐C catalysts with isolated single cobalt atoms have been synthesized and compared with cobalt nanoparticles for formic acid dehydrogenation. The atomically dispersed Co‐N‐C catalyst achieves superior activity, better acid resistance, and improved long‐term stability compared with nanoparticles synthesized by a similar route. High‐angle annular dark‐field–scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, electron paramagnetic resonance, and X‐ray absorption fine structure characterizations reveal the formation of CoIINx centers as active sites. The optimal low‐cost catalyst is a promising candidate for liquid H2 generation. 相似文献