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1.
Tian Yongmei Huang Jichun Gao Yuan Cao Dianxue Wang Guiling 《Journal of Solid State Electrochemistry》2012,16(5):1901-1906
Fe–N–C catalysts were prepared through metal-assisted polymerization method. Effects of carbon treatment, Fe loading, nitrogen
source, and calcination temperature on the catalytic performance of the Fe–N–C for H2O2 electroreduction were measured by voltammetry and chronoamperometry. The Fe–N–C catalyst shows optimal performance when prepared
with pretreated active carbon, 0.2 wt.% Fe, paranitroaniline (4-NA) and one-time calcination. The Fe–N–C catalyst displayed
good performance and stability for electroreduction of H2O2 in alkaline solution. An Al–H2O2 semi-fuel cell was set up with Fe–N–C catalyst as cathode and Al as anode. The cell exhibits an open-circuit voltage of 1.3 V
and its power density reached 51.4 mW cm−2 at 65 mA cm−2. 相似文献
2.
Pritha Talukder Shyamapada Shit Heinrich N?th Matthias Westerhausen Alexander Nikolai Kneifel Samiran Mitra 《Transition Metal Chemistry》2012,37(1):71-77
A heterobimetallic cyano-bridged 1D coordination polymer of the composition [Ni(baepn)(μ-NC)Fe(CN)3(NO)(μ-CN)]n·3H2O has been synthesized by the reaction of nickel(II) nitrate hexahydrate, baepn (baepn = N, N′-bis(2-aminoethyl)-1,3-propanediamine), and sodium nitroprusside dihydrate in a methanol–water mixture. The complex was characterized
by physicochemical and spectroscopic methods. The crystal structure was established by single-crystal X-ray diffraction analysis.
It reveals cyano-bridged heterometallic chains consisting of alternating arrays of Ni(II) and Fe(II) atoms, both being embedded
in distorted octahedral environments. Low-temperature susceptibility measurements show the presence of weak antiferromagnetic
exchange interactions between paramagnetic Ni(II) centers (J = −0.46 cm−1) through long diamagnetic [Fe(CN)5(NO)]2− bridges. Spin state of the iron atom was established by 57Fe M?ssbauer spectroscopy. 相似文献
3.
In this work we prepared the hybrid material (SG) by the sol–gel method through the reaction between tetraethylortosilicate
(TEOS) and acetylacetonatepropyltrimethoxysilane (ACACSIL). We also immobilized the acetylacetonate on silica surface (GR)
by the grafting method through the reaction between a commercial silica and ACACSIL. Infrared thermal analysis showed that
these materials were thermally stable until 200 °C. SG is a microporous material and has surface area of 500 m2 g−1, average porous volume of 0.09 cm3 g−1 and organic content of 1 mmol g−1. GR is a mesoporous material and has surface area of 300 m2 g−1, average porous volume of 0.7 cm3 g−1 and organic content of 0.4 mmol g−1. Iron(III) was coordinated to SG and GR resulting in the SG–Fe and GR–Fe silicas which were tested as catalysts on the aerobic
epoxidation of cis-cyclooctene. SG–Fe yielded 100% of conversion and 94% of selectivity in epoxide whereas GR–Fe silica led
to a maximum conversion of 50% and 100% of selectivity. 相似文献
4.
Shen-Ming Chen Wen-Yan Chzo R. Thangamuthu 《Journal of Solid State Electrochemistry》2008,12(11):1487-1495
Electrochemically active hybrid coatings based on cationic films, didodecyldimethylammonium bromide (DDAB), and poly(diallyldimethylammonium
chloride) (PDDAC) are prepared on electrode surface by cycling the film-covered electrode repetitively in a pH 6.5 solution
containing Fe(CN)6
3− and Ru(CN)6
4− anions. Modified electrodes exhibited stable and reversible voltammetric responses corresponding to characteristics of Fe(CN)6
3−/4− and Ru(CN)6
4−/3− redox couples. The cyclic voltammetric features of hybrid coatings resemble that of electron transfer process of surface-confined
redox couple. Electrochemical quartz crystal microbalance results show that more amounts of electroactive anionic complexes
partitioned into DDAB coating than those doped into PDDAC coating from the same doping solution. Peak potentials of hybrid
film-bound redox couples showed a negative shift compared to those at bare electrode and this shift was more pronounced in
the case of DDAB. Finally, the advantages of hybrid coatings in electrocatalysis are demonstrated with sulfur oxoanions. 相似文献
5.
Four pyridinecarboxamide iron dicyanide building blocks and one Mn(III) compound have been employed to assemble cyanide-bridged
heterometallic complexes, resulting in a series of trinuclear cyanide-bridged FeIII–MnII complexes: {[Mn(DMF)2 (MeOH)2][Fe(bpb)(CN)2]2}·2DMF (1), {[Mn(MeOH)4][Fe(bpmb)(CN)2]2}·2MeOH·2H2O (2), {[Mn(MeOH)4][Fe(bpdmb)(CN)2]2}·2MeOH·2H2O (3) and {[Mn(MeOH)4][Fe(bpClb)(CN)2]2}·4MeOH (4) (bpb2− = 1,2-bis(pyridine-2-carboxamido)benzenate, bpmb2− = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpdmb2− = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate, bpClb2− = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate). Single-crystal X-ray diffraction analysis shows their similar sandwich-like
structures, in which the two cyanide-containing building blocks act as monodentate ligands through one of their two cyanide
groups to coordinate the Mn(II) center. Investigation of the magnetic properties of these complexes reveals antiferromagnetic
coupling between the neighboring Fe(III) and Mn(II) centers through the bridging cyanide group. A best fit to the magnetic
susceptibilities of complexes 1 and 3 gave the magnetic coupling constants J = −1.59(2) and −1.32(4) cm−1, respectively. 相似文献
6.
Radhey M. Naik Raj K. Tiwari Pradeep K. Singh Shiv Bali S. Yadav Abhas Asthana 《Transition Metal Chemistry》2008,33(5):615-623
It is observed that Ag(I) catalyzes the rate of substitution of phenylhydrazine (PhNHNH2) into hexacyanoferrate(II), producing a cherry red colored complex, [Fe(CN)5PhNHNH2]3−. The reaction was monitored at 488 nm leading to the formation of the complex under the conditions: [Fe(CN)6]4− (5.0 × 10−3 mol dm−3), PhNHNH2 (2.0 × 10−3 mol dm−3), temperature (25 ± 0.1 °C), pH (2.8 ± 0.02), and ionic strength, I (0.02 mol dm−3), (KNO3). Under optimum conditions, absorbance at fixed times (A
t
) is linearly related to Ag(I) in the concentration range 10.79–97.08 ng cm−3, in the presence of several diverse ions. The highest percentage error and relative standard deviations in the entire range
of Ag(I) determination are found to be 2.5% and 0.16, with a detection limit of 8.75 ng cm−3 of silver(I). The experimental accuracies expressed in terms of percentage recoveries are in the range of 97.87–102.50. The
method was successfully applied for the determination of Ag(I) in a few synthetic samples and found to be in good agreement
with those obtained from atomic absorption spectrophotometry (AAS). The validity of the proposed method has also been tested
for Ag(I) determination in spiked drinking water samples. The present catalytic kinetic method (CKM) is highly sensitive,
selective, reproducible, and inexpensive. A review of recently published catalytic spectrophotometric methods for determination
of Ag(I) has also been presented for comparison. 相似文献
7.
Liliana Hechavarría Narcizo Mendoza Patricia Altuzar Hailin Hu 《Journal of Solid State Electrochemistry》2010,14(2):323-330
Transparent and ionic conductive polymeric electrolytes have been prepared through sol–gel method by adding titanium isopropoxide
into an acidic polyethylene glycol (PEG) solution. After hydrolysis and condensation processes, new associations between titanium
cations and ether oxygen atoms of PEG have been formed according to Fourier-transform infrared spectroscopy. Thermogravimetric
analysis results of these hybrid materials indicate a better thermal stability with a less polydispersion of the molecular
mass distribution in comparison with PEG. For the purpose of electrochromic or photoelectrochromic device applications, LiI
was added into the hybrid materials to form solvent-free polymeric electrolytes. Optical transmittance spectra of these electrolytes
show a red shift of the cutoff wavelength as a function of titanium isopropoxide percentage in the original sol–gel solutions.
It is also observed that the amount of hydroxyl groups in the hybrid materials was reduced in comparison with the PEG one.
This makes electrical conductivity of the hybrid electrolytes with LiI salt insensitive to humidity and solvents, which was
about 2 × 10-4 Ω−1 cm−1 at room temperature. A solid WO3-based electrochromic device with the hybrid electrolyte keeps the same optical transmittance value after 1,000 cycles of
switching polarization potentials between −1 and +1 V. 相似文献
8.
We investigate effects of Fe dopant concentration on the structure, as well as low temperature Raman scattering and electrical
transport properties in SrTi1−x
Fe
x
O3 (x = 0.00, 0.10, 0.20, 0.30, 0.40) nanoparticles prepared by sol-gel method. The results show an average particle size of powder
is about 30 nm, and the lattice parameters decrease as increasing the Fe content. In the Raman spectra, a broad structure
in the region 200–500 cm−1 is almost absent and the peaks in the region 600–800 cm−1 show different weights with respect to SrTiO3, relating to structural changes with increasing dopant concentration in conjunction with increasing grain boundary contribution
to the impedance. The abrupt change in Raman peak position as function of temperature suggests a phase transition in our samples
in the range of 110–150 K. These results indicate that the Fe ion has replaced the site of Ti in unit cell. These results
also demonstrate the feasibility of synthesizing the compound with low annealing temperature. 相似文献
9.
Jiawei Zhang Xiaobin Huang Hao Wei Jianwei Fu Yawen Huang Xiaozhen Tang 《Journal of Solid State Electrochemistry》2012,16(1):101-107
Solid composite polymer electrolytes consisting of polyethylene oxide (PEO), LiClO4, and porous inorganic–organic hybrid poly (cyclotriphosphazene-co-4, 4′-sulfonyldiphenol) (PZS) nanotubes were prepared using the solvent casting method. Differential scanning calorimetry
and scanning electron microscopy were used to determine the characteristics of the composite polymer electrolytes. The ionic
conductivity, lithium ion transference number, and electrochemical stability window can be enhanced after the addition of
PZS nanotubes. The electrochemical impedance showed that the conductivity was improved significantly. Maximum ionic conductivity
values of 1.5 × 10−5 S cm−1 at ambient temperature and 7.8 × 10−4 S cm−1 at 80 °C were obtained with 10 wt.% content of PZS nanotubes, and the lithium ion transference number was 0.35. The good
electrochemical properties of the solid-state composite polymer electrolytes suggested that the porous inorganic–organic hybrid
polyphosphazene nanotubes had a promising use as fillers in SPEs and the PEO10–LiClO4–PZS nanotube solid composite polymer electrolyte might be used as a candidate material for lithium polymer batteries. 相似文献
10.
Yu. G. Gol’tsov L. A. Matkovskaya V. G. Il’in 《Theoretical and Experimental Chemistry》1999,35(1):57-61
Features of the localization of various types of cations and their distribution between the structural elements of the framework
of faujasite with encapsulated hexacyanide complexes of iron(II) and cobalt(III) were established. The content of the alkali-metal
cations in the sodalite cells is increased compared with faujasite, and the cations of the transition metals are localized
in the large cavities with the formation of Me(SII)−NC−Fe(CN)5 (Me=Cu, Co) and (NC)5Fe−CN−Me(SV)−NC−Fe(CN)5 (Me=Ni, Cu, Co) fragments.
L. V. Pisarzhevskii Institute of Physical Chemsitry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039,
Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 35, No. 1, pp. 56–61, January–February, 1999. 相似文献
11.
Functionalized polypyrrole films were prepared by incorporation of Fe(CN)6
3− as doping anion during the electropolymerization of pyrrole at a glassy carbon electrode from aqueous solution. The electrochemical
behavior of the Fe(CN)6
3−/Fe(CN)6
4− redox couple in polypyrrole was studied by cyclic voltammetry. An obvious surface redox reaction was observed and dependence
of this reaction on the solution pH was illustrated. The electrocatalytic ability of polypyrrole film with ferrocyanide incorporated
was demonstrated by oxidation of ascorbic acid at the optimized pH of 4 in a glycine buffer. The catalytic effect for mediated
oxidation of ascorbic acid was 300 mV and the bimolecular rate constant determined for surface coverage of 4.5 × 10−8 M cm−2 using rotating disk electrode voltammetry was 86 M−1 s−1. Furthermore, the catalytic oxidation current was linearly dependent on ascorbic acid concentration in the range 5 × 10−4–1.6 × 10−2 M with a correlation coefficient of 0.996. The plot of i
p versus v
1/2 confirms the diffusion nature of the peak current i
p.
Received: 12 April 1999 / Accepted: 25 May 1999 相似文献
12.
A novel terbium 2-methyl-benzoimidazole-5-carboxylic acid complex was prepared and incorporated into silica matrix (tetraethoxysilane)
using a mild sol–gel technique. We then successfully fabricated a terbium luminescent xerogel, which maintained intense green
emission even in pure water. The emission was rapidly (~1 s) quenched by ClO− (detection limit 10−5 M) but not NO3
−, CH3COO−, F−, Cl−, Br−, I−, CO3
−, and OH−. The selectivity appears to be due to the high vibrational energy of ClO− as well as its strong oxidation capability. 相似文献
13.
Changzhou Yuan Long Yang Linrui Hou Diankai Li Laifa Shen Fang Zhang Xiaogang Zhang 《Journal of Solid State Electrochemistry》2012,16(4):1519-1525
A facile hydrothermal strategy was first proposed to synthesize flower-like Co(OH)2 hierarchical microspheres. Further physical characterizations revealed that the flower-like Co(OH)2 microspherical superstructures were self-assembled by one-dimension nanobelts with rich mesopores. Electrochemical performance
of the flower-like Co(OH)2 hierarchical superstructures were investigated by cyclic voltammgoram, galvanostatic charge–discharge and electrochemical
impedance spectroscopy in 3 M KOH aqueous electrolyte. Electrochemical data indicated that the flower-like Co(OH)2 superstructures delivered a specific capacitance of 434 F g−1 at 10 mA cm−2 (about 1.33 A g−1), and even kept it as high as 365 F g−1 at about 5.33 A g−1. Furthermore, the SC degradation of about 8% after 1,500 continuous charge–discharge cycles at 5.33 A g−1 demonstrates their good electrochemical stability at large current densities. 相似文献
14.
A. Tamayo L. Téllez J. Rubio F. Rubio J. L. Oteo 《Journal of Sol-Gel Science and Technology》2010,55(1):94-104
Hybrid materials based on tetraethoxysilane (TEOS), tetrabutyl orthotitanate (TBOT), and hydroxyl terminated polydimethyl
siloxane (PDMS) have been prepared and characterized. The effects of HCl concentration and PDMS molecular weight (MW) have been analysed. The physical and chemical characteristics have been discussed based on the results obtained from the
characterization by Raman spectroscopy, nitrogen adsorption, mercury intrusion porosimetry and inverse gas chromatography
(IGC). Specific surface areas (SSA) and pore volumes increase with HCl concentration and are independent on the PDMS Mw. SSA
values as high as 300 m2 g−1 have been obtained for hybrid materials prepared with HCl:(TEOS + TBOT) concentration of 0.3 and PDMS Mw of 550 g mol−1. These materials present the higher pore volumes and lower pore sizes. However, for HCl:(TEOS + TBOT) concentration of 0.5,
only macroporous materials are obtained with SSA values as low as 2–4 m2 g−1, and pore sizes close to 10 μm. In general the presence of Ti on the SSA and porosities give a little decrease in such values.
Surface energies are consistent with those of organic–inorganic materials. Dispersive surface energies are higher for the
Si–Ti hybrid materials and, for all of them, they decrease with both HCl concentration and PDMS Mw. This result can be assigned
to the presence of a higher concentration of PDMS (or CH3 groups) on the surface of the hybrid material as well as the presence of disordered anatase-like structures. On the other
hand, the acid and base properties are dependent on both HCl concentration and PDMS Mw. It has been observed that the acid
and base parameters of the Si–Ti hybrid materials are influenced by the disorder degree of the amorphous titanium oxide present
in them. As the disorder decrease both acid and base parameters increase. 相似文献
15.
Zhang Kou-Lin Xu Yan Wang Zheng Jin Chuan-Ming You Xiao-Zeng 《Transition Metal Chemistry》2002,27(1):95-98
The nitrosyl cyanide [Cu(L)Fe(CN)5NO] was prepared by the reaction of [Cu(L)]Cl2 [L = 3, 10-bis(2-hydroxymethyl)-1,3,5,8,10,12-hexaazacyclotetradecane] with Na2[Fe(CN)5NO]·2H2O in aqueous solution. Single-crystal analysis revealed that the title complex is the first structurally characterized dinuclear copper(II)–iron(II) complex based on the nitroprusside. Variable temperature magnetic susceptibility measurements (4.0–180.0 K) show the occurrence of very weak antiferromagnetic interactions between the copper(II) ions with zJ = –0.410 cm–1. 相似文献
16.
A. K. Arof N. E. A. Shuhaimi N. A. Alias M. Z. Kufian S. R. Majid 《Journal of Solid State Electrochemistry》2010,14(12):2145-2152
In this work, a chitosan/iota (ι)-carrageenan blended film doped with orthophosphoric acid (H3PO4) as ionic dopant and poly(ethylene glycol) (PEG) as plasticizer has been used as a separator and electrolyte in an electrical
double layer capacitor (EDLC). A set of samples were prepared by the solution cast technique to see the effect of the different
weight ratios of the proton donor and plasticizer on the conductivity. The highest conducting sample has composition 37.50 wt.%
chitosan–37.50 wt.% ι-carrageenan–18.75 wt.% H3PO4–6.25 wt.% PEG. The conductivity value is 6.29 × 10−4 S cm−1. The conductivity–temperature relationship is Arrhenian, and the activation energy for the highest conducting sample is 0.09 eV.
The specific discharge capacitance of the EDLC is 35 F g−1 at 0.11 mA cm−2 current drain and was constant for 30 cycles. 相似文献
17.
Ar and Kr matrix effect on the geometry and Cl–H stretching (ν
s
(Cl–H)) and librational (ν
l
(Cl–H)) frequencies of the hydrogen-bonded complex Cl–H···NH3 are simulated within the framework of polarizable continuum model with integral equation formalism (IEF-PCM) at B3LYP and
MP2 levels of theory with the basis set 6-311++G(2df,2pd). Within the framework of B3LYP and IEF-PCM, the simulated gas phase,
Ar, and Kr matrix ν
s
(Cl–H) of the complex are 2140, 1684, and 1550 cm−1, respectively, which deviate from the experimental values (~2200, 1371, and 1218 cm−1) by −60, 313, and 332 cm−1. Within the framework of MP2 and IEF-PCM, the gas phase, Ar, and Kr matrix ν
s
(Cl–H) are calculated as 2366, 2037, and 1957 cm−1 by the harmonic approximation, and as 2177, 1876, and 1665 cm−1 by the full-dimensional anharmonic correction. The matrix effect modeling is of greater importance than the anharmonic correction
in accounting for the large experimental gas phase to Ar or Kr matrix shift of the ν
s
(Cl–H) (−829 or −982 cm−1). Our calculations do not support the assignment of the 733.8 and 736.9 cm−1 bands to the Ar and Kr matrix ν
l
(Cl–H). 相似文献
18.
Development of activated carbon from vine shoots by physical and?chemical activation methods. Some insight into activation mechanisms 总被引:1,自引:0,他引:1
M. Ruiz-Fernández M. Alexandre-Franco C. Fernández-González V. Gómez-Serrano 《Adsorption》2011,17(3):621-629
Activated carbons (ACs) are prepared from vine shoots (VS) by the method of physical activation in air, CO2 and steam atmospheres and by the method of chemical activation with H3PO4, ZnCl2 and KOH aqueous solutions. The ACs were characterized texturally by N2 adsorption at −196 °C, mercury porosimetry, and density measurements. The method of chemical activation has been proved to
be more effective than the method of physical activation to prepare ACs with a well-developed porosity. ACs with high micro-
and mesopore volumes are prepared with ZnCl2 and H3PO4. Using ZnCl2, the volume of micropores is 0.62 cm3 g−1 and the volume of mesopores is 0.81 cm3 g−1. A greater development of macroporosity is obtained by KOH activation. The volume of macropores is as high as 1.13 cm3 g−1 for the resulting AC. Yield of the process of preparation of the ACs is low for the method of chemical activation. Some insights
into the performance of the activating agents in the activation process are provided. 相似文献
19.
Grace O. Ogunlusi Jide Ige Olayinka A. Oyetunji Jonathan F. Ojo 《Transition Metal Chemistry》2009,34(5):483-491
The kinetics of the reactions between azido-pentacyanocobaltate(III), Co(CN)5N3
3−, and iron(II) polypyridyl complexes, Fe(LL)3
2+ (LL = bipy, phen), have been studied in both neutral and acidic aqueous solutions at I = 0.1 mol dm−3 NaCl. The reactions were carried out under pseudo-first-order conditions in which the concentration of Fe(LL)3
2+ was kept constant, and the second-order rate constants obtained for the reactions at 35 °C were within the range of 0.156–0.219
dm3 mol−1 s−1 for LL = bipy and 0.090–0.118 dm3 mol−1 s−1 for LL = phen. Activation parameters were measured for these systems. The dependence of reaction rates on acid was studied
in the range [H+] = 0.001–0.008 mol dm−3. The reaction in acid medium shows interesting kinetics. Two reactive species were identified in acid medium, namely, the
protonated cobalt complex and the azido-bridged binuclear complex. The electron-transfer process is proposed to go by mixed
outer- and inner-sphere mechanisms in acid medium, in which electron transfer through the bridged inner-sphere complex (k
5) is slower than through the outer-sphere path (k
4).
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
I. A. Koval' K. B. Yatsimirskii S. Trofimenko V. V. Pavlishchuk 《Theoretical and Experimental Chemistry》1998,34(6):323-326
The new trinuclear complex K{(CoTpt-Bu)[Fe(CN)6](CoTpt-Bu)}, in which the initial structural fragments are linked by CN− bridges, was synthesized by the directed stitching of mononuclear complexes, one of which was [Fe(CN)6]3− while the other was cobalt(II) tris(3-tert-butyl-l-pyrazolyl)borate ([(CoTpt-Bu)]+). The magnetic moment of K{(CoTpt-Bu)[Fe(CN)6](CoTpt-Bu)} at 292 K was 8.07 μβ (S=7/2), indicating the absence of antiferromagnetic exchange interactions in the trinuclear complex.
Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 34, No. 6, pp. 351–354, November–December, 1998. 相似文献