CHINESE JOURNAL OF CATALYSIS
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2015
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IF 1.964
Fu Yang,Shuying Gao,Cuirong Xiong,Haiqing Wang,Jin Chen,Yan Kong
The different amounts of [5,10,15,20-tetrakis-(pentafluorophenyl)porphyrin] manganese chloride (TF 20 PPMnCl) were immobilized on amino-functionalized MCM-41 for catalysis of the hydroxylation of naphthalene . The samples were characterized by X-ray powder diffraction, N 2 adsorption/desorption isotherms, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, diffuse reflectance ultraviolet-visible spectroscopy, thermogravimetric and differential scanning calorimetry , and inductively coupled plasma mass spectrometry . The results indicated that the manganese porphyrins were axially coordinated on amino-functionalized MCM-41. The prepared samples showed remarkable catalytic activity in the hydroxylation of naphthalene with meta -chloroperbenzoic acid as the oxidant. The catalyst could be reused several times without loss of its activity.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2015
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IF 1.964
Zhixin Zhang,Yehong Wang,Min Wang,Jianmin Lü,Lihua Li,Zhe Zhang,Mingrun Li,Jingyang Jiang,Feng Wang
We herein report the effects of CeO 2 crystal planes on the oxidative coupling of alcohols and amines to form imines. CeO 2 exhibits significant catalytic activity under mild reaction conditions (60 °C) during the synthesis of 13 different imines, giving >89% conversions and >90% selectivities. The crystal planes of CeO 2 greatly affect the catalytic performance. Among the crystal planes investigated (the (110), (100) and (111) planes), the (110) plane shows the strongest redox ability and thus the best catalytic activity, generating a 97% yield of the imine at 60 °C in 2 h, because it contains the highest concentration of oxygen vacancies.
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高影响因子
Journal of Energy Chemistry
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2015
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IF 2.352
Xinping Ouyang,Guodian Zhu,Xiangzhen Huang,Xueqing Qiu
The microwave assisted liquefaction process of wheat straw alkali lignin was investigated to obtain monophenolic compounds as the precursor of bio-fuel. It is found that the total yield of monophenolic compounds is significantly improved under microwave irradiation, reaching 15.77% under a relatively mild liquefaction condition of 10 wt% H 2 SO 4 as the catalyst, 10 wt% phenol as the hydrogen-donor reagent at 120 °C for 40 min. Compared with conventional thermal liquefaction process, microwave irradiation promotes the cleavage of C–C bonds, which gives an extra 29% of C aryl –C α bond cleavage , and increases the yield of monophenolic compounds from 0.92% to 13.61% under the same conditions. The excessive temperature and prolonged time under microwave irradiation will promote the recondensation of degraded lignin fragments, so the key to obtain high yield of monophenolic compounds is to avoid the recondensation reaction. The selected solid catalyst promotes the dissociation of methoxy groups, and the addition of phenol into liquefaction can only slightly improve the yield of monophencolic compounds.
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高影响因子
Journal of Energy Chemistry
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2015
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IF 2.352
Guiquan Zhang,Xin Zhang,Ting Bai,Tengfei Chen,Wentao Fan
The coking kinetics and reaction-regeneration on Zn/HZSM-5 (Zn/HZ) catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene (BTX) yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.
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高影响因子
Journal of Energy Chemistry
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2015
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IF 2.352
Feifei Sun,Yue An,Lecheng Lei,Fuying Wu,Jingke Zhu,Xingwang Zhang
Hydrogenation of carbazole and N-ethylcarbazole over Raney-Ni catalyst were realized in the temperature range of 393–503 K. 4[H] adduct dominated the hydrogenation products and the formation of 2[H] adduct was the rate-limiting step during the period, in which the conversion of carbazole was less than 40%. The hydrogenation process followed pseudo-first-order kinetics and the hydrogenation activation energies of carbazole and N-ethylcarbazole were 90 kJ/mol and 115 kJ/mol, respectively. The reaction starting position as well as the pathway of the hydrogenation of (N-ethyl)carbazole were investigated by comparing the kinetic characteristics of hydrogen uptake of carbazole and N-ethylcarbazole. The results showed that the reaction was a stepwise hydrogenation process and the first H 2 was added to the C1 = C10 double bond in the hydrogenation.
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高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2015
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IF 0.754
Fu-Xing XU,Qian-Kun DANG,Yin-Juan CHEN,Kai YANG,Qiang WANG,Bin CHEN,Yuan-Yuan WANG,Chuan-Fan DING
A fast mass analysis method using digital ion trap technology was reported. The mass analysis was realized by scanning the frequency of digital RF voltage and dipole ion resonance voltage during ion injection period without the conventional ion cooling, ion resonance ejection or ion cleaning process. It can decrease about three fourth of traditional analysis time using ion trap mass spectrometry. The ion signal was optimized through the modification of frequency scanning rate, ion gate voltage and other experimental parameters. For example, an optimal mass spectroscopy of reserpine ( m / z 609) and arginine ( m / z 174) were obtained when the ion gate voltage was 9 V and the digital RF frequency was scanned from 1 MHz to 400 kHz at rate of 2385 Th s −1 . The results indicated that the obtained mass spectra were in very good agreement with conventional analytical method using ion trap mass analyzer.
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高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
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2015
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IF 1.178
Chang-xin LI,Hong ZHONG,Shuai WANG,Jian-rong XUE,Fang-fang WU,Zhen-yu ZHANG
The extraction of manganese from low-grade manganese oxide ores using CaS derived from CaSO 4 as reductant was investigated. The effects of mass ratio of CaS to ore, reduction temperature, reduction time, liquid to solid ratio (L/S ratio), stirring speed, leaching temperature, leaching time and H 2 SO 4 concentration on the leaching rates of Mn and Fe during the reduction–acid leaching process were discussed. The leaching rates of 96.47% for Mn and 19.24% for Fe were obtained under the optimized conditions of mass ratio of CaS to manganese oxide ore 1:6.7, L/S ratio 5:1, stirring speed 300 r/min, reduction temperature of 95 °C for 2.0 h in the reduction process and leaching stirring speed of 200 r/min, H 2 SO 4 concentration of 1.5 mol/L, leaching temperature of 80 °C for 5 min in the leaching process. In addition, this process can be employed in the recovery of manganese from various manganese oxide ores, and Mn leaching rate above 95% is obtained.
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高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2015
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IF 0.754
Yi-Ping CAI,Zhi-Wei SUN,Xiao-Yan WANG,You-Rui SUO,Jin-Mao YOU
A method for determination of 6 plant growth regulators by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupled with isotope-coded derivatization was developed. d 0 -10-Methyl-acridone-2-sulfonyl piperazine (d 0 -MASPz, light form) and d 3 -10-methyl-acridone-2-sulfonyl piperazine (d 3 -MASPz, heavy form) were prepared as isotope-coded derivatization reagents for carboxyl compound. The carboxylic plant growth regulator standards and real samples were derivatized by d 0 -MASPz and d 3 -MASPz, respectively. The obtained solutions were mixed at a certain ratio, and then injected for HPLC-MS/MS analysis. The light and heavy derivatives were monitored with transitions of [M + H] + → m / z 208.2 and [M + H] + → m / z 211.2, respectively. With heavy derivative as internal standard for corresponding light derivative, the global isotope internal standard quantification for 6 plant growth regulators was achieved. The results indicated that the proposed isotope-coded derivatization method could provide relative quantitative data with adequate linearity in a 10-fold dynamic range ( R = 0.9991). The detection and quantitation limits were 0.19–0.34 μM and 0.53–0.96 μM, respectively. The relative standard deviations were ≤ 3.8%, and the accuracies ranged from 97. 5% to 103.8%.
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高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2015
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IF 0.754
Liang-Liang HUANG,Yan HUANG,Yan-Kai CHEN,Yun-Hua DING,Wei-Feng ZHANG,Xiao-Jing LI,Xiao-Ping WU
A simple and green method for the determination of trace bisphenol A (BPA) was established by coupling supported ionic liquid solid-phase extraction to β -cyclodextrin modified ionic liquids carbon paste electrode-based electrochemical detection (SILs-SPE-ED). The synthesized imidazolium ionic liquids modified styrene type macroporous resin was used as adsorbent for SPE of BPA. The experimental parameters that affected the extraction efficiency were investigated and optimized. Dynamic adsorption test showed that the maximum adsorption capacity of BPA on the SILs-SPE cartridge was 10.1 mg g −1 , and the enrichment factor was 40. The calibration curve showed a good linearity between the anodic current and the BPA concentration in the range of 1.0 × 10 −8 −1.0 × 10 −6 M. The detection limit was 4.16 nM (equal to 0.95 μg L −1 ). The SILs-SPE-ED method, with the advantages including high sensitivity and good practicability, was applied to the analysis of real water and plastic samples, and the results agreed well with HPLC method.
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高影响因子
NEW CARBON MATERIALS
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2015
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IF 0.979
Gang Wang,Li-tao Jia,Bo Hou,De-bao Li,Jun-gang Wang,Yu-han Sun
Fabricating self-supporting, three dimensional graphene macroscopic structures from two dimensional graphene sheets by self-assembly has been an intriguing subject in exploring the performance of graphene structures for practical advanced applications. Monolithic graphene hydrogels (GHs) with quite good mechanical properties and excellent resilience were self-assembled from graphene oxide (GO) dispersions under hydrothermal conditions by changing the pH value. The structure-property relationships and the self-assembly behavior of GHs were investigated. It was found that the formation of GHs was pH-dependent. The charge state of carboxyl groups on the graphene was the key factor that influenced the balance of attraction and repulsion interactions of the GO and consequently determined the self-assembly behavior. Both the graphene molecular structure and colloidal interactions were correlated with the unique self-assembly behavior, which can be used to design graphene arrangements with various structures, functions and mechanical properties. This method is superior to the conventional method that adjusts the concentration and reduction time of the GO dispersion.
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高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
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2016
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IF 1.34
Dong HUANG,Ming-yu ZHANG,Qi-zhong HUANG,Li-ping WANG,Xian TANG,Xin YANG,Kai TONG
A novel SiC–ZrB 2 coating was prepared using a two-step technique by slurry-sintering and chemical vapor reaction on carbon/carbon (C/C) composites. The SiC–ZrB 2 coating was composed of the scattered ZrB 2 phase and the continuous SiC phase. It was observed that a good adhesion was built between the coating and the C/C composites. The SiC–ZrB 2 coating samples exhibited a better ablation resistance in comparison with the uncoated C/C composites. The SiO 2 –ZrO 2 barrier layer, the heat dissipation of the gaseous products and the pinning effect of ZrO 2 all contributed to the good ablation resistance of the SiC–ZrB 2 coated composites.
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CHINESE JOURNAL OF CATALYSIS
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2016
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IF 2.628
Zhifeng Dai,Fang Chen,Qi Sun,Yanyan Ji,Liang Wang,Xiangju Meng,Feng-Shou Xiao
An efficient catalyst system based on a Pd-metalated porous organic polymer bearing phenanthroline ligands was designed and synthesized. This catalyst was applied to various C–C bond-forming reactions, including the Suzuki, Heck and Sonogashira couplings, and afforded the corresponding products while exhibiting excellent activities and selectivities. More importantly, this catalyst can be readily recycled. These features show that such catalysts have significant potential applications in the future.
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高影响因子
危险品化学品经营许可证（带存储）