CATALYSIS COMMUNICATIONS
·
2019
·
IF 3.674
Cuncun Zuo,Yun Tian,Yanxia Zheng,Lei Wang,Zhongjun Fu,Tiantian Jiao,Ming Wang,Haofei Huang,Yuchao Li
Series of gold and ceria supported γ-Al 2 O 3 catalysts were developed for the oxidative esterification of methacrolein with methanol. All the catalysts were prepared through one step deposition-precipitation method, and K 2 CO 3 and urea were used as precipitant, respectively. Au, CeO 2 and γ-Al 2 O 3 could self-assemble unique particle morphology during co-precipitation process and form semi-core shell or core shell structure after calcination . The relationship between catalytic reactivity and structural characteristics were analyzed by SEM, TEM, EDS, BET, XRD, XPS, etc. Among Au-CeO 2 /γ-Al 2 O 3 (K 2 CO 3 ), Au-Ce/γ-Al 2 O 3 (Urea) and Au/γ-Al 2 O 3 (Urea) catalysts with different active components and precipitant, the last two exhibited higher catalytic activity. Moreover, the Ce-doped catalysts shown higher stability than just Au supported on pure alumina. The active stability of the optimum Au-Ce/γ-Al 2 O 3 catalyst was evaluated with seven-time cyclic reactions exhibiting high stability and activity with the yield of MMA above 90%.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Renjing Zhang,Yanjian Wan,Jiali Peng,Gang Yao,Yunhong Zhang,Bo Lai
In this study, LaCoO 3 /Al 2 O 3 (LCA) was utilized as a heterogeneous catalyst to activate peroxymonosulfate (PMS) to degrade atrazine (ATZ). The structural properties of the catalysts were characterized by SEM, EDS, XRD, XPS and TPD. The effects of some key parameters (i.e., loadings of LCA, ATZ concentration, catalyst dosage, PMS concentration, initial pH and coexisting ions) were optimized. In addition, under the optimal conditions of 100 mg/L 23LCA, 100 mg/L PMS and initial solution pH 6.8, the removal rate and mineralization efficiency of ATZ (5 mg/L) reached 100% and 30.8%, respectively. The superiority of the 23LCA/PMS system was verified by two controlled experiments. After three cycles of experiments, the degradation effect of ATZ was within an acceptable range. The degradation intermediates of ATZ were detected by UPLC-QTOF-MS/MS, and the possible degradation pathway of ATZ was proposed. In addition, the presence of SO 4 − and HO was identified by quenching experiments and SO 4 − was verified as the predominant radical. Finally, based on the comprehensive analysis, a reasonable reaction mechanism of the 23LCA/PMS system was proposed. In a word, these results indicate that LCA can act as a highly efficient heterogeneous catalyst to activate PMS to degrade ATZ in water.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Hang Qin,Wenming Guo,Hanning Xiao
Sol-gel process was modified by reverse micelles (RMs) for the preparation of γ-Al 2 O 3 ultrafiltration (UF) membranes and their applications in the efficient rejection of methyl blue and bovine serum albumin were explored. The optimized boehmite sol with a narrower particle size distribution and better sphericity was synthesized by using cetyltrimethyl ammonium bromide RMs as microreactors and was dip-coated on α-Al 2 O 3 microfiltration substrates to prepare γ-Al 2 O 3 UF membranes. It was found that not only the sol particle size, it's distribution and morphology had also an important effect on the pore size, pore size distribution , porosity and pore volume of the membrane. Additionally, the as-prepared membranes with a MWCO of 8 kDa exhibited a narrow pore size distribution (4.8–6.8 nm), relatively high pure-water flux (30.4 L/(h m 2 bar)) and excellent rejection for bovine serum albumin and methyl blue with the maximum rejection rate of 96.2% and 96.8% respectively.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Qun Yuan,Hong-Hua Ge,Jun-Yi Sha,Le-Tian Wang,Chuan Wan,Feng Wang,Kai Wu,Xin-Jing Meng,Yu-Zeng Zhao
The influence of Al 2 O 3 nanoparticles on the corrosion behavior of brass in simulated cooling water (SCW) with or without sodium dodecyl benzene sulfonate (SDBS) was investigated by means of electrochemical impedance spectroscopy , polarization curves, scanning electron microscope, energy spectrum analysis, X-ray diffraction and Fourier transform infrared spectroscopy . Results indicate that the brass suffered severe corrosion in SCW and the SCW-Al 2 O 3 nanofluid. The main corrosion product was Zn 5 (OH) 6 (CO 3 ) 2 . Al 2 O 3 nanoparticles promoted both anodic and cathodic processes in the brass electrode, and dezincification was most serious in the SCW-Al 2 O 3 nanofluid. The adsorption of SDBS on the brass surface was enhanced, and a more compact protective film was formed on the brass surface in the SCW-Al 2 O 3 -SDBS nanofluid. As a result, the corrosion resistance of brass was increased in this medium.
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Yu Kang,Ming Tian,Chuande Huang,Jian Lin,Baolin Hou,Xiaoli Pan,Lin Li,Alexandre I. Rykov,Junhu Wang,Xiaodong Wang
It is of great significance to improve the syngas selectivity of Fe-based oxygen carriers (OCs), because of their sufficient lattice oxygen, low cost, and environmental compatibility in chemical looping partial oxidation of CH4. In this work, it was found that the addition of Y could remarkably increase CO selectivity of Fe2O3/Al2O3 to 98% with a CH4 conversion of ∼90%. X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterizations combined with Mössbauer spectroscopy illustrated that the incorporation of Y led to the Fe species gradually transferring from Fe2O3 into the garnet structure (Y3Fe2Al3O12), a newly formed phase, which was found to be highly active for syngas generation. Density functional theory (DFT) calculations demonstrated that such a high CO selectivity of confined Fe species in garnet originated from enhanced oxygen vacancy formation energy (Eov), compared with Fe2O3, which resulted from the lattice oxygen shared by not only reducible Fe ions but also nonreducible Al and Y ones in a garnet structure. Therefore, our work provides a meaningful guidance of new materials screening for methane partial oxidation in the chemical looping process.
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2015
·Vol. 5
·期 2
·606-633
·
IF 2
Hongmei Qin,Xiaoshuang Qian,Tao Meng,Yi Lin,Zhen Ma
Conventional supported Pt catalysts have often been prepared by loading Pt onto commercial supports, such as SiO2, TiO2, Al2O3, and carbon. These catalysts usually have simple metal-support (i.e., Pt-SiO2) interfaces. To tune the catalytic performance of supported Pt catalysts, it is desirable to modify the metal-support interfaces by incorporating an oxide additive into the catalyst formula. Here we prepared three series of metal oxide-modified Pt catalysts (i.e., Pt/MOx/SiO2, Pt/MOx/TiO2, and Pt/MOx/Al2O3, where M = Al, Fe, Co, Cu, Zn, Ba, La) for CO oxidation. Among them, Pt/CoOx/SiO2, Pt/CoOx/TiO2, and Pt/CoOx/Al2O3showed the highest catalytic activities. Relevant samples were characterized by N2adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), H2temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), CO temperature-programmed desorption (CO-TPD), O2temperature-programmed desorption (O2-TPD), and CO2temperature-programmed desorption (CO2-TPD).Keywords:Pt catalysts;cobalt oxide;CO oxidation
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2014
·Vol. 90
·期 3
·415-422
·
IF 2.494
Yanping Chen,Yiming Xu,Dang-guo Cheng,Yingcai Chen,Fengqiu Chen,Xiaoyong Lu,Yiping Huang,Songbo Ni
BACKGROUND The synthesis of C 2 –C 4 hydrocarbons from coal or biomass-derived syngas has received increasing attention because of the resource constraints of petroleum. The present study explores direct production of hydrocarbons from syngas over bifunctional catalyst containing methanol synthesis catalyst CuO–ZnO–Al 2 O 3 (CZA) and SAPO-34 zeolite. RESULTS The synthesis of C 2 –C 4 hydrocarbons from syngas was investigated over CZA/SAPO-34 bifunctional catalyst at temperatures ranging from 240 to 440°C. The results indicate that higher temperatures aggregate Cu metal and lead to the deactivation of CZA. The predominant products are dimethyl ether (DME) and methanol at temperatures from 280 to 360°C and a small amount of hydrocarbons are found due to the deactivation of SAPO-34 caused by a type of coke named ‘inert coke’. While 96.5% selectivity of C 2 –C 4 hydrocarbons in products of all hydrocarbons can be obtained at 400°C with less coke named ‘active coke’. CONCLUSION Reaction temperatures have significant effect on the selectivity of C 2 –C 4 hydrocarbons and coke species of SAPO-34. The ‘active coke’ of poly methyl-substituted benzene/naphthalene (MB/MN) acts both as an intermediate and as coke deposition. The ‘inert coke’ of poly methyl-substituted adamantine (MA) and other groups-substituted benzene/naphthalene acts only as coke depositions. Comprehensive consideration of the characteristics of this bifunctional catalyst, shows that a moderate temperature for C 2 –C 4 hydrocarbons synthesis from syngas might be approximately 400°C. © 2014 Society of Chemical Industry
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 93
·51184-51193
·
IF 3.708
Qing Zhang,Tao Wu,Peng Zhang,Ruijuan Qi,Rong Huang,Xuefeng Song,Lian Gao
Hydrogen reduction of hierarchical spinel intermediates that were synthesized by a facile hydrothermal method results in Ni/γ-Al2O3 nanocomposites with Ni nanoparticles (∼5.5 nm) well dispersed and embedded in nanoflakes of the hollow Al2O3 microspheres. The good dispersion of small metal nanoparticles and strong metal–support interactions that resulted from decomposition of spinel intermediates during reduction are essential for the efficient and sustainable high temperature dry reforming of methane (DRM) catalysis. The high surface area (170 m2 g−1) composite catalysts show coke and sintering resistance in long term DRM catalysis at 750 °C, the highest temperature ever tested for hierarchical nanostructures. Ni loadings and the calcination temperatures of the spinel intermediate are investigated for their effect on the morphology and the catalytic performance of the final catalysts. It is interesting that some initially non-active control catalysts can be activated during long term testing.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2017
·Vol. 25
·期 3
·719-726
·
IF 1.624
Hu Xuebing,Yu Yun,Ren Shuang,Lin Na,Wang Yongqing,Zhou Jianer
To achieve superior separation performance in the phenol aqueous solutions treatment, a novel graphene oxide/Al 2 O 3 composite membrane was prepared by a spin coating process. The microstructure measurement shows that the composite membrane has a multilayer structure and graphene oxide has been tightly coated on the surface of the Al 2 O 3 membrane interlayer homogeneously. During the treatment of phenol aqueous solutions, the permeation flux and phenol rejection of the composite membrane were investigated. The results show the permeation flux of the membrane is about 1.153 L m −2 h −1 bar −1 and the phenol rejection of the membrane increases to 99.9% when the phenol concentration is 0.01 g L −1 . The high phenol rejection of the composite membrane is mainly attributed to the physical sieving, the solution–diffusion effect and the hydrophobic nature of graphene oxide. All these results indicate the GO/Al 2 O 3 composite membrane is a suitable material for the removal of phenol from aqueous solutions in environmental pollution management.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Shifeng Huang,Feng Gao,Qinggang Li,Xin Cheng
Samples with various ratios of AlN/Al 2 O 3 were fabricated via vacuum hot-pressing at 1700 °C under an applied pressure of 30 MPa for 90 min using Y 2 O 3 as a sintering aid. The densification process, microstructural development, and formation of AlON phase from Al 2 O 3 and AlN were investigated. Al 2 O 3 additive can improve the physical and mechanical properties , and purification of the grain boundaries. AlON are almost formed completely when the content of Al 2 O 3 is 80 vol%. The effects of composition, microstructure, and exposure time at 1400 °C on the oxidation behavior of AlN samples with different amounts of Al 2 O 3 were investigated. The sample with 80 vol% alumina has the best oxidation resistance .
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Zhongbin Pan,Lingmin Yao,Jiwei Zhai,Dezhou Fu,Bo Shen,Haitao Wang
Flexible electrostatic capacitors are potentially applicable in modern electrical and electric power systems. In this study, flexible nanocomposites containing newly structured one-dimensional (1D) BaTiO3@Al2O3 nanofibers (BT@AO NFs) and the ferroelectric polymer poly(vinylidene fluoride) (PVDF) matrix were prepared and systematically studied. The 1D BT@AO NFs, where BaTiO3 nanoparticles (BT NPs) were embedded and homogeneously dispersed into the AO nanofibers, were successfully synthesized via an improved electrospinning technique. The additional AO layer, which has moderating dielectric constant, was introduced between BT NPs and PVDF matrixes. To improve the compatibility and distributional homogeneity of the nanofiller/matrix, dopamine was coated onto the nanofiller. The results show that the energy density due to high dielectric polarization is about 10.58 J cm–3 at 420 MV m–1 and the fast charge–discharge time is 0.126 μs of 3.6 vol % BT@AO-DA NFs/PVDF nanocomposite. A finite element simulation of the electric-field and electric current density distribution revealed that the novel-structured 1D BT@AO-DA NFs significantly improved the dielectric performance of the nanocomposites. The large extractable energy density and high dielectric breakdown strength suggest the potential applications of the BT@AO-DA NFs/PVDF nanocomposite films in electrostatic capacitors and embedded devices.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2016
·
IF 2.75
Yi Li,Muhammad Nadeem Amin,Xingmei Lu,Chunshan Li,Fuqiang Ren,Suojiang Zhang
The catalyst NiO/MgO–Al 2 O 3 was prepared by loading magnesium and nickel onto the surface of γ-Al 2 O 3 beads, respectively, and was adapted to in situ upgrade the high temperature pyrolysis vapor derived from coal pyrolysis. The catalyst synthesis process, and structural variation were characterized by the XRD, SEM, and physical adsorption analyzer. In order to examine the catalytic effect on the different nickel loading ratio in the catalysts, the solid–liquid–gas product distribution, variation of gas and components of coal tar were studied by simulated distillation, GC/MS, elemental analysis and so on. The results shows both the tar yield and the content of the light fraction in the tar can be increased by catalytic up grade. The catalyst has a strong ability to convert the heavy component and polycyclic aromatic hydrocarbons in the tar to lower molecular weight components.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）