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2016 Volume 33 Issue 8
2016, 33(8): 855-866
doi: 10.11944/j.issn.1000-0518.2016.08.160240
Abstract:
GaN-based white light-emitting diode(LED) is now an emerging backlight technology for large color gamut and high efficiency liquid crystal displays. In this technology, phosphors are key materials to control the color-space coverage, luminous efficiency, and lifetime of the backlight units, which are required to have a desired emission and a narrow emission band. β-Sialon:Eu2+(sialon:silicon aluminum oxynitride, Si6-zAlzOzN8-z) is such a green phosphor because it has an emission band centered at 525~545 nm and a small band width(~55 nm). This contribution overviews the synthesis, luminescence, electronic and crystal structure, reliability and applications of β-sialon:Eu2+. From both structure calculations and experimental observations, Eu2+ is seen to be accommodated into a large void along the c-axis, and coordinated to six nitrogen/oxygen atoms at an equivalent distance. The narrow emission band is thus ascribed to the high symmetry of the local structure of Eu2+. Both of the emission band and the band width of β-sialon:Eu2+ can be tuned by tailoring the composition(e.g., the z value), and β-sialon:Eu2+ with shorter wavelengths and narrower bands can be achieved at lower z values. Combined with other red phosphors, β-sialon:Eu2+ enables to produce wider color gamut backlights(15% up) than the conventional yttrium aluminum garnet(YAG)-based ones. Both the excellent luminescence properties and reliability make β-sialon:Eu2+ to be an extremely important green phosphor for use in advanced displays.
GaN-based white light-emitting diode(LED) is now an emerging backlight technology for large color gamut and high efficiency liquid crystal displays. In this technology, phosphors are key materials to control the color-space coverage, luminous efficiency, and lifetime of the backlight units, which are required to have a desired emission and a narrow emission band. β-Sialon:Eu2+(sialon:silicon aluminum oxynitride, Si6-zAlzOzN8-z) is such a green phosphor because it has an emission band centered at 525~545 nm and a small band width(~55 nm). This contribution overviews the synthesis, luminescence, electronic and crystal structure, reliability and applications of β-sialon:Eu2+. From both structure calculations and experimental observations, Eu2+ is seen to be accommodated into a large void along the c-axis, and coordinated to six nitrogen/oxygen atoms at an equivalent distance. The narrow emission band is thus ascribed to the high symmetry of the local structure of Eu2+. Both of the emission band and the band width of β-sialon:Eu2+ can be tuned by tailoring the composition(e.g., the z value), and β-sialon:Eu2+ with shorter wavelengths and narrower bands can be achieved at lower z values. Combined with other red phosphors, β-sialon:Eu2+ enables to produce wider color gamut backlights(15% up) than the conventional yttrium aluminum garnet(YAG)-based ones. Both the excellent luminescence properties and reliability make β-sialon:Eu2+ to be an extremely important green phosphor for use in advanced displays.
2016, 33(8): 867-875
doi: 10.11944/j.issn.1000-0518.2016.08.160174
Abstract:
Traditional supercapacitors have low energy density, which in most cases hinders their further practical applications, therefore, people more focus on studies of the structure-composition-property relationship of electrode materials towards high performance supercapacitors during present research and development of electrochemical energy storage devices. This article summarizes the history of research and development of novel supercapacitors, as well as their challenges and strategies, with the aim to find novel supercapacitor systems via searching for high efficient electrode materials and electrolytes. Novel electrode materials and redox electrolytes are thus particularly emphasized herein, for example, some promising electrode materials of colloidal ion supercapacitor systems have shown some advantages compared to those ex-situ prepared electrode materials, which indicates high electrochemical reactivity existing in the colloidal state of constituent transitional and rare earth metal cations. Furthermore, we also introduce novel lithium-ion supercapacitors as some promising research and development directions. On the basis of the current status of research and development of supercapacitors, it is highly expected to combine the advantages of both battery electrode materials and supercapacitor electrode materials towards the so-called supercapattery or supercabattery, which may be dominant in the field of future electrochemical energy storage devices.>
Traditional supercapacitors have low energy density, which in most cases hinders their further practical applications, therefore, people more focus on studies of the structure-composition-property relationship of electrode materials towards high performance supercapacitors during present research and development of electrochemical energy storage devices. This article summarizes the history of research and development of novel supercapacitors, as well as their challenges and strategies, with the aim to find novel supercapacitor systems via searching for high efficient electrode materials and electrolytes. Novel electrode materials and redox electrolytes are thus particularly emphasized herein, for example, some promising electrode materials of colloidal ion supercapacitor systems have shown some advantages compared to those ex-situ prepared electrode materials, which indicates high electrochemical reactivity existing in the colloidal state of constituent transitional and rare earth metal cations. Furthermore, we also introduce novel lithium-ion supercapacitors as some promising research and development directions. On the basis of the current status of research and development of supercapacitors, it is highly expected to combine the advantages of both battery electrode materials and supercapacitor electrode materials towards the so-called supercapattery or supercabattery, which may be dominant in the field of future electrochemical energy storage devices.>
2016, 33(8): 876-886
doi: 10.11944/j.issn.1000-0518.2016.08.160206
Abstract:
Toll-like receptors(TLRs) are evolutionarily conserved innate immunity receptor proteins that detect pathogen-associated molecular patterns(PAMPs), danger-associated molecular patterns(DAMPs) and xenobiotic-associated molecular patterns(XAMPs), triggering inflammatory responses. TLR4 is the main receptor for bacterial lipopolysaccharide(LPS) and the accessory protein myeloid differentiation factor 2(MD-2) is responsible for ligand recognition. LPS binding induces(TLR4-MD-2-LPS)2 and TLR4/MD-2 complex dimeriztion, which activates TLR4 signaling and produce pro-inflammatory factors. The dysregulation of innate immune TLR4 signaling contributes to numerous pathological diseases. Therefore, TLR4/MD-2 is emerging as an important drug discovery target. In this review, we summarize the up-to-date discovery of TLR4 small molecule modulators and provide insights into future drug discovery, which will be interesting to colleagues major in chemical biology, medicinal chemistry, signal transduction and translational medicine.
Toll-like receptors(TLRs) are evolutionarily conserved innate immunity receptor proteins that detect pathogen-associated molecular patterns(PAMPs), danger-associated molecular patterns(DAMPs) and xenobiotic-associated molecular patterns(XAMPs), triggering inflammatory responses. TLR4 is the main receptor for bacterial lipopolysaccharide(LPS) and the accessory protein myeloid differentiation factor 2(MD-2) is responsible for ligand recognition. LPS binding induces(TLR4-MD-2-LPS)2 and TLR4/MD-2 complex dimeriztion, which activates TLR4 signaling and produce pro-inflammatory factors. The dysregulation of innate immune TLR4 signaling contributes to numerous pathological diseases. Therefore, TLR4/MD-2 is emerging as an important drug discovery target. In this review, we summarize the up-to-date discovery of TLR4 small molecule modulators and provide insights into future drug discovery, which will be interesting to colleagues major in chemical biology, medicinal chemistry, signal transduction and translational medicine.
2016, 33(8): 887-893
doi: 10.11944/j.issn.1000-0518.2016.08.150423
Abstract:
In both nonisothermal and isothermal treatments, crystallization and melting behaviors of poly(L-lactic acid)(PLLA) with different optical purities(91.6%, 93.3%, 94.0%, 97.0%, 98.4%) were investigated by differential scanning calorimetery(DSC) and wide-angle X-ray diffraction(WAXD).With the increase of optical purities of PLLA, the crystallization rate, the melting enthalpy, crystallization temperature and melting point increase. The Avrami index(n) is about 3, indicating a three-dimensional spherulitic growth on heterogeneous nuclei during the isothermal process. The crystalline structure of PLLA is independent on the variation of optical purities of PLLA. However, the critical temperature for crystal formation from δ-form to α-form crystals increases during the isothermal crystallization process with optical purities increasing of PLLA. All the results show that the crystallization and melting behaviors are dependent on the optical purities of PLLA.
In both nonisothermal and isothermal treatments, crystallization and melting behaviors of poly(L-lactic acid)(PLLA) with different optical purities(91.6%, 93.3%, 94.0%, 97.0%, 98.4%) were investigated by differential scanning calorimetery(DSC) and wide-angle X-ray diffraction(WAXD).With the increase of optical purities of PLLA, the crystallization rate, the melting enthalpy, crystallization temperature and melting point increase. The Avrami index(n) is about 3, indicating a three-dimensional spherulitic growth on heterogeneous nuclei during the isothermal process. The crystalline structure of PLLA is independent on the variation of optical purities of PLLA. However, the critical temperature for crystal formation from δ-form to α-form crystals increases during the isothermal crystallization process with optical purities increasing of PLLA. All the results show that the crystallization and melting behaviors are dependent on the optical purities of PLLA.
2016, 33(8): 894-899
doi: 10.11944/j.issn.1000-0518.2016.08.150362
Abstract:
The kinetics of surface phase separation in PMMA/SAN[poly(methyl methacrylate)/poly(styrene-ran-acrylonitrile)] blend film with off-critical component has been investigated by means of in situ AFM(atomic force microscopy). Our results indicate that the surface phase separation observed exists three stages. The exponent of zero in the first stage validate the Cahn theory; In the second one, the phase behaviors are mainly controlled by Brownian-Diffusion, corresponding to the exponent of 1/3. The hydrokinetics in the last stage results in the occurrence of 2/3 as the characteristic exponent. Our results are significant for not only the understanding of phase separation of polymer blend, but also the engineering and application of polymer films.
The kinetics of surface phase separation in PMMA/SAN[poly(methyl methacrylate)/poly(styrene-ran-acrylonitrile)] blend film with off-critical component has been investigated by means of in situ AFM(atomic force microscopy). Our results indicate that the surface phase separation observed exists three stages. The exponent of zero in the first stage validate the Cahn theory; In the second one, the phase behaviors are mainly controlled by Brownian-Diffusion, corresponding to the exponent of 1/3. The hydrokinetics in the last stage results in the occurrence of 2/3 as the characteristic exponent. Our results are significant for not only the understanding of phase separation of polymer blend, but also the engineering and application of polymer films.
2016, 33(8): 900-904
doi: 10.11944/j.issn.1000-0518.2016.08.150401
Abstract:
A facile synthesis of 2,3,3',4'-biphenyltetracarboxylic dianhydride through cross-coupling of halo-substituted orthoxylene and liquid-phase oxidation of the resulted tetramethylbiphenyl. 2,3,3',4'-Tetramethylbiphenyl(3,4'-TMDP) was synthesized by cross-coupling of 4-bromo-1,2-dimethylbenzene and 3,4-dimethylphenylmagnesium bromide with NiF2-PPh3(PPh3:triphenylphosphine) as the catalyst and which was then converted to 2,3,3',4'-biphenyltetracarboxylic dianhydride(3,4'-BPDA) by the oxidation and dehydration procedures. The overall yield reached to 74%. In comparison with the preparations of 3,4'-BPDA from dimethyl phthalate or chlorinated dimethyl phthalate mixture, the method exhibits advantages in the separation and environmental benign because of the avoidance of the tedious hydrolysis step and the separation of isomers.
A facile synthesis of 2,3,3',4'-biphenyltetracarboxylic dianhydride through cross-coupling of halo-substituted orthoxylene and liquid-phase oxidation of the resulted tetramethylbiphenyl. 2,3,3',4'-Tetramethylbiphenyl(3,4'-TMDP) was synthesized by cross-coupling of 4-bromo-1,2-dimethylbenzene and 3,4-dimethylphenylmagnesium bromide with NiF2-PPh3(PPh3:triphenylphosphine) as the catalyst and which was then converted to 2,3,3',4'-biphenyltetracarboxylic dianhydride(3,4'-BPDA) by the oxidation and dehydration procedures. The overall yield reached to 74%. In comparison with the preparations of 3,4'-BPDA from dimethyl phthalate or chlorinated dimethyl phthalate mixture, the method exhibits advantages in the separation and environmental benign because of the avoidance of the tedious hydrolysis step and the separation of isomers.
2016, 33(8): 905-912
doi: 10.11944/j.issn.1000-0518.2016.08.150397
Abstract:
Seven nitrile-containing gambogic acid derivatives were synthesized from gambogic acid(GA) through introducing different alkylnitriles or arylnitriles on the C-30 carboxyl of gambogic acid. Six of them are new compounds(1~6). Their structures were identified by 1H NMR and MS analysis. The evaluation of antitumor bioactivities in vitro on the hepatoma cells(HepG2), colon adenocarcinoma cells(RKO) and ovarian adenocarcinoma cells(OVCAR-3) were done by the methylthiazolydiphenyl-tetrazolium bromide(MTT) method. The results show that most of the synthesized compounds have strong antitumor activities. Among them, the antitumor activities of compounds 4 and 6 are more potent than that of gambogic acid.
Seven nitrile-containing gambogic acid derivatives were synthesized from gambogic acid(GA) through introducing different alkylnitriles or arylnitriles on the C-30 carboxyl of gambogic acid. Six of them are new compounds(1~6). Their structures were identified by 1H NMR and MS analysis. The evaluation of antitumor bioactivities in vitro on the hepatoma cells(HepG2), colon adenocarcinoma cells(RKO) and ovarian adenocarcinoma cells(OVCAR-3) were done by the methylthiazolydiphenyl-tetrazolium bromide(MTT) method. The results show that most of the synthesized compounds have strong antitumor activities. Among them, the antitumor activities of compounds 4 and 6 are more potent than that of gambogic acid.
2016, 33(8): 913-922
doi: 10.11944/j.issn.1000-0518.2016.08.150386
Abstract:
A series of novel acylhydrazone compounds was synthesized by a simple and efficient condensation of 1,3-dimethy-5-formyllbarbituric acids with aryloxy/arylamino acetylhydrazides and nitrogen-containing heterocyclic acetylhydrazides under microwave irradiation. The structures of all new compounds were confirmed by elemental analysis, IR, 1H NMR, mass spectrometry and single-crystal X-ray diffraction analysis. In vitro antimicrobial activity evaluation results show that some of the target compounds exhibit superior antimicrobial activities compared with ciprofloxacin. Structure-activity relationship analysis shows that when the aryl group is a nitrogen-containing heterocyclic compound, its antibacterial activity is significantly stronger than that of a benzene ring compound. One of target compounds 2t shows the strongest activities against S.Aureus with the minimum inhibitory concentration(MIC) of 0.8 g/L and against E.Coli with the MIC of 1.6 g/L.
A series of novel acylhydrazone compounds was synthesized by a simple and efficient condensation of 1,3-dimethy-5-formyllbarbituric acids with aryloxy/arylamino acetylhydrazides and nitrogen-containing heterocyclic acetylhydrazides under microwave irradiation. The structures of all new compounds were confirmed by elemental analysis, IR, 1H NMR, mass spectrometry and single-crystal X-ray diffraction analysis. In vitro antimicrobial activity evaluation results show that some of the target compounds exhibit superior antimicrobial activities compared with ciprofloxacin. Structure-activity relationship analysis shows that when the aryl group is a nitrogen-containing heterocyclic compound, its antibacterial activity is significantly stronger than that of a benzene ring compound. One of target compounds 2t shows the strongest activities against S.Aureus with the minimum inhibitory concentration(MIC) of 0.8 g/L and against E.Coli with the MIC of 1.6 g/L.
2016, 33(8): 923-931
doi: 10.11944/j.issn.1000-0518.2016.08.150398
Abstract:
Two hydrazone componds(E)-N'-(2,4-dihydroxybenzylidene)-pyrrole-2-carbohydrazide C12H11N3O3(Ⅰ) and (E)-N'-(2-hydroxy-3-methoxybenzylidene)-pyrrole-2-carbohydrazide C13H14N3O4(Ⅱ) have been synthesized from 2,4-dihydroxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde with pyrrole-2-carbohydrazide, respectively. The compounds have been characterized by IR spectroscopy, elemental analysis, 1H NMR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. The crystal of compound Ⅰ belonged to monoclinic crystal lattice, space group P21/c, Z=4, with unit cell parameters a=1.2586(4) nm, b=0.8050(3) nm, c=1.1914(4) nm, and compound Ⅱ crystallized in the orthorhombic system, space group P212121, Z=4, with unit cell parameters a=0.4756(2) nm, b=1.2491(6) nm, c=2.2145(11) nm. The TG-DTG result shows that the compounds Ⅰ and Ⅱ display good thermal stability, the maximum decomposition peaks are at the temperature of 267.59 ℃ and 284.79 ℃, and their apparent activation energy values are 176.6 kJ/mol and 122.9 kJ/mol, respectively. The thermogenic curves of the compounds Ⅰ and Ⅱ reacting with calf thymus DNA(CT-DNA) measured by viscosity and microcalorimetry, indicate that the interactions of compounds Ⅰ and Ⅱ with CT-DNA belong to the intercalation mode, and the interacting processes are all endothermic, their enthalpies are ΔH(Ⅰ)=4.67 kJ/mol and ΔH(Ⅱ)=4.40 kJ/mol, respectively.
Two hydrazone componds(E)-N'-(2,4-dihydroxybenzylidene)-pyrrole-2-carbohydrazide C12H11N3O3(Ⅰ) and (E)-N'-(2-hydroxy-3-methoxybenzylidene)-pyrrole-2-carbohydrazide C13H14N3O4(Ⅱ) have been synthesized from 2,4-dihydroxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde with pyrrole-2-carbohydrazide, respectively. The compounds have been characterized by IR spectroscopy, elemental analysis, 1H NMR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. The crystal of compound Ⅰ belonged to monoclinic crystal lattice, space group P21/c, Z=4, with unit cell parameters a=1.2586(4) nm, b=0.8050(3) nm, c=1.1914(4) nm, and compound Ⅱ crystallized in the orthorhombic system, space group P212121, Z=4, with unit cell parameters a=0.4756(2) nm, b=1.2491(6) nm, c=2.2145(11) nm. The TG-DTG result shows that the compounds Ⅰ and Ⅱ display good thermal stability, the maximum decomposition peaks are at the temperature of 267.59 ℃ and 284.79 ℃, and their apparent activation energy values are 176.6 kJ/mol and 122.9 kJ/mol, respectively. The thermogenic curves of the compounds Ⅰ and Ⅱ reacting with calf thymus DNA(CT-DNA) measured by viscosity and microcalorimetry, indicate that the interactions of compounds Ⅰ and Ⅱ with CT-DNA belong to the intercalation mode, and the interacting processes are all endothermic, their enthalpies are ΔH(Ⅰ)=4.67 kJ/mol and ΔH(Ⅱ)=4.40 kJ/mol, respectively.
2016, 33(8): 932-938
doi: 10.11944/j.issn.1000-0518.2016.08.150402
Abstract:
A new complex [Cu(Phen)(Nap)2]2·(EtOH)2·(H2O)2(Phen=1,10-phenanthroline; Nap=1-naphthoic acid; EtOH=ethyl alcohol) was synthesized. The compound was characterized by elemental analysis, FTIR, TG-DTG, single crystal X-ray diffraction. The complex is dinuclear copper(Ⅱ) structure. The electrochemical and luminescent properties of the complex was studied by cyclic voltammetry and emission spectrum. The interactions of the complex with calf thymus DNA(ct-DNA) has been studied by UV and fluorescence spectroscopy. The results show that the copper(Ⅱ) complex shows irreversible redox process, and possesses a fluorescent emission band at 416 nm, and this copper(Ⅱ) complex binds to ct-DNA in groove binding and its intrinsic binding constant Kb is 4.68×103 L/mol.
A new complex [Cu(Phen)(Nap)2]2·(EtOH)2·(H2O)2(Phen=1,10-phenanthroline; Nap=1-naphthoic acid; EtOH=ethyl alcohol) was synthesized. The compound was characterized by elemental analysis, FTIR, TG-DTG, single crystal X-ray diffraction. The complex is dinuclear copper(Ⅱ) structure. The electrochemical and luminescent properties of the complex was studied by cyclic voltammetry and emission spectrum. The interactions of the complex with calf thymus DNA(ct-DNA) has been studied by UV and fluorescence spectroscopy. The results show that the copper(Ⅱ) complex shows irreversible redox process, and possesses a fluorescent emission band at 416 nm, and this copper(Ⅱ) complex binds to ct-DNA in groove binding and its intrinsic binding constant Kb is 4.68×103 L/mol.
2016, 33(8): 939-944
doi: 10.11944/j.issn.1000-0518.2016.08.150374
Abstract:
This paper presents an efficient synthesis of stable isotope labeled D4-rhodamine B from deuterated orthoxylene through oxidation and its reaction with 3-diethylaminophenol in 36.9% total yield. The deuterated product was confirmed by mass spectrometry(MS) and nuclear magnetic resonance(NMR). Its chemical purity is higher than 98.0% by high performance liquid chromatography(HPLC), and isotopic enrichment is higher than 98.0%(atom D). D4-rhodamine B was used as internal standard for the determination of rhodamine B in orange juice with linear calibration curve of 0.05~50 mg/L, limit for determination of 5 μg/kg, recovery of 96.4%~103.4% and relative standard deviation(RSD) of 1.0%~1.2%. This method is proved to be accurate and sensitive for the determination of rhodamine in food safety.
This paper presents an efficient synthesis of stable isotope labeled D4-rhodamine B from deuterated orthoxylene through oxidation and its reaction with 3-diethylaminophenol in 36.9% total yield. The deuterated product was confirmed by mass spectrometry(MS) and nuclear magnetic resonance(NMR). Its chemical purity is higher than 98.0% by high performance liquid chromatography(HPLC), and isotopic enrichment is higher than 98.0%(atom D). D4-rhodamine B was used as internal standard for the determination of rhodamine B in orange juice with linear calibration curve of 0.05~50 mg/L, limit for determination of 5 μg/kg, recovery of 96.4%~103.4% and relative standard deviation(RSD) of 1.0%~1.2%. This method is proved to be accurate and sensitive for the determination of rhodamine in food safety.
2016, 33(8): 945-950
doi: 10.11944/j.issn.1000-0518.2016.08.150455
Abstract:
The volatile oils of the flower, leaf, stem and fruit from Amygdalus persica var. persica f. duplex extracted by supercritical carbon dioxide are analyzed by GC-MS. There are 178 components identified and their relative mass fractions are determined. The main constituents and mass concentration are benzaldehyde(11.42%), α-farnesene(9.18%) and n-hexadecanoic acid(8.03%) from the flower, benzaldehyde(14.72%), pentacosane(9.85%), octacosane(8.29%) and tricosane(5.14%) from the leaf, (Z)-3- hexen-1-ol(28.90%), (E)-2-hexen-1-ol(16.06%) and 1-hexanol(6.86%) from the stem, benzaldehyde(20.46%), n-hexadecanoic acid(5.84%) and benzyl alcohol(5.01%) from the fruit. The volatile oils of the flower, leaf, stem and fruit lower the contents of peroxides and acid value of peanut oil during 10~40 d storage period. The volatile oils of the flower and stem show significant antimicrobial activities with the minimum inhibitory concentration(MIC) of 0.024~0.188 g/L.
The volatile oils of the flower, leaf, stem and fruit from Amygdalus persica var. persica f. duplex extracted by supercritical carbon dioxide are analyzed by GC-MS. There are 178 components identified and their relative mass fractions are determined. The main constituents and mass concentration are benzaldehyde(11.42%), α-farnesene(9.18%) and n-hexadecanoic acid(8.03%) from the flower, benzaldehyde(14.72%), pentacosane(9.85%), octacosane(8.29%) and tricosane(5.14%) from the leaf, (Z)-3- hexen-1-ol(28.90%), (E)-2-hexen-1-ol(16.06%) and 1-hexanol(6.86%) from the stem, benzaldehyde(20.46%), n-hexadecanoic acid(5.84%) and benzyl alcohol(5.01%) from the fruit. The volatile oils of the flower, leaf, stem and fruit lower the contents of peroxides and acid value of peanut oil during 10~40 d storage period. The volatile oils of the flower and stem show significant antimicrobial activities with the minimum inhibitory concentration(MIC) of 0.024~0.188 g/L.
2016, 33(8): 951-959
doi: 10.11944/j.issn.1000-0518.2016.08.150425
Abstract:
Unsupported Ni-Mo hydrodesulfurization catalysts were prepared by a coprecipitation method and characterized by X-ray diffraction(XRD), nitrogen physisorption measurement(BET), infrared spectroscopy(Py-IR, FI-IR), H2-temperaure programmed reduction(H2-TPR), temperature-programmed desorption of NH3(NH3-TPD), Laser Raman spectroscopy(LRS) and gas chromatography analysis(GC-PFPD) tests. The effects of Al2O3 and phosphorus addition on the structure of the catalysts were studied. The results indicate that the addition of Al2O3 greatly increases the pore diameter, specific surface area, the amount of the L acid sites and also promotes the formation of B acid sites. Addition of phosphorus leads to the formation of the Al-P-O structure instead of the NiAl2O4 structure, and weakens the interaction between active phase and Al2O3. The amount of tetrahedral Mo species decreases while the anount of octahedral Mo species increases. The catalysts has a longer service life. The catalyst acidity is changed from strong to weak by adding phosphorus. The hydrodesulfurization rate is increased from 94% to 99.8%. At 280 ℃, hydrogen pressure of 4 MPa, liquid hourly space velocity(LHSV) of 1.5 h-1 and hydrogen-to-oil volume ratio of 500, 4-methyldibenzothiophene, 4,6-dimethyldibenzothiophene and 2,4,6-trimethyldibenzothiophene catalytic cracking are depthly removed in fluid catalytic cracking diesel oil; the sulphur concentration is decreased from 3950 μg/g to 7.9 μg/g.
Unsupported Ni-Mo hydrodesulfurization catalysts were prepared by a coprecipitation method and characterized by X-ray diffraction(XRD), nitrogen physisorption measurement(BET), infrared spectroscopy(Py-IR, FI-IR), H2-temperaure programmed reduction(H2-TPR), temperature-programmed desorption of NH3(NH3-TPD), Laser Raman spectroscopy(LRS) and gas chromatography analysis(GC-PFPD) tests. The effects of Al2O3 and phosphorus addition on the structure of the catalysts were studied. The results indicate that the addition of Al2O3 greatly increases the pore diameter, specific surface area, the amount of the L acid sites and also promotes the formation of B acid sites. Addition of phosphorus leads to the formation of the Al-P-O structure instead of the NiAl2O4 structure, and weakens the interaction between active phase and Al2O3. The amount of tetrahedral Mo species decreases while the anount of octahedral Mo species increases. The catalysts has a longer service life. The catalyst acidity is changed from strong to weak by adding phosphorus. The hydrodesulfurization rate is increased from 94% to 99.8%. At 280 ℃, hydrogen pressure of 4 MPa, liquid hourly space velocity(LHSV) of 1.5 h-1 and hydrogen-to-oil volume ratio of 500, 4-methyldibenzothiophene, 4,6-dimethyldibenzothiophene and 2,4,6-trimethyldibenzothiophene catalytic cracking are depthly removed in fluid catalytic cracking diesel oil; the sulphur concentration is decreased from 3950 μg/g to 7.9 μg/g.
2016, 33(8): 960-967
doi: 10.11944/j.issn.1000-0518.2016.08.150359
Abstract:
The adsorption mechanism of Hg on pure CeO2 surface was studied by the density functional theory. The adsorption energy of Hg on different surfaces and different sites of CeO2 was calculated by two-dimensional supercell model of p(3×3). The results show that the adsorption capacity of Hg on pure CeO2 is weak, which is a physical adsorption, and the Hg atom and CeO2 do not form effective chemical bonds. In order to further study the adsorption mechanism of Hg on CeO2 related surface, the adsorption mechanism of Hg on Pd doped CeO2(Pd-CeO2) surface was also studied. The results show that the adsorption capacity of Hg on Pd-CeO2 is strong, which is a chemical adsorption, and the Hg atom and Pd-CeO2 form effective chemical bonds. The adsorption capacity of Hg on CeO2 surface is enhanced due to the doping of Pd. In order to further quantify the adsorption efficiency of Hg on the surface of pure CeO2 and Pd-CeO2, the experimental study has been carried on. The experimental results show that the adsorption efficiency of Hg on pure CeO2 is low, and doping of Pd can effectively improve the adsorption efficiency of CeO2, which are consistent with the results of theoretical calculation.
The adsorption mechanism of Hg on pure CeO2 surface was studied by the density functional theory. The adsorption energy of Hg on different surfaces and different sites of CeO2 was calculated by two-dimensional supercell model of p(3×3). The results show that the adsorption capacity of Hg on pure CeO2 is weak, which is a physical adsorption, and the Hg atom and CeO2 do not form effective chemical bonds. In order to further study the adsorption mechanism of Hg on CeO2 related surface, the adsorption mechanism of Hg on Pd doped CeO2(Pd-CeO2) surface was also studied. The results show that the adsorption capacity of Hg on Pd-CeO2 is strong, which is a chemical adsorption, and the Hg atom and Pd-CeO2 form effective chemical bonds. The adsorption capacity of Hg on CeO2 surface is enhanced due to the doping of Pd. In order to further quantify the adsorption efficiency of Hg on the surface of pure CeO2 and Pd-CeO2, the experimental study has been carried on. The experimental results show that the adsorption efficiency of Hg on pure CeO2 is low, and doping of Pd can effectively improve the adsorption efficiency of CeO2, which are consistent with the results of theoretical calculation.
2016, 33(8): 968-976
doi: 10.11944/j.issn.1000-0518.2016.08.150396
Abstract:
New water-soluble magnetic and fluorescent Fe3O4@SiO2@ZrO2:Tb3+ nanocomposites(NCs) have been successfully synthesized through the in situ synthesized method. The morphology, size, phase, magnetic properties and fluorescent properties of as-synthesized nanoparticles(NPs) were well investigated by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), magnetometer, and photoluminescence(PL) spectra. The magnetic and fluorescent NPs consist of silica-coated Fe3O4 as the core and the ZrO2:Tb3+ as the shell exhibit superparamagnetism with the saturation magnetization of 36 emu/g and fluorescence properties with four emission bands peaked at approximately 494 nm(5D4→7F6), 549 nm(5D4→7F5), 587 nm(5D 4→7F4), and 625 nm(5D4→7F3) of Tb3+ ions. The bifunctional magnetic and fluorescence NCs will show potential applications in biomedical fields in the future.
New water-soluble magnetic and fluorescent Fe3O4@SiO2@ZrO2:Tb3+ nanocomposites(NCs) have been successfully synthesized through the in situ synthesized method. The morphology, size, phase, magnetic properties and fluorescent properties of as-synthesized nanoparticles(NPs) were well investigated by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), magnetometer, and photoluminescence(PL) spectra. The magnetic and fluorescent NPs consist of silica-coated Fe3O4 as the core and the ZrO2:Tb3+ as the shell exhibit superparamagnetism with the saturation magnetization of 36 emu/g and fluorescence properties with four emission bands peaked at approximately 494 nm(5D4→7F6), 549 nm(5D4→7F5), 587 nm(5D 4→7F4), and 625 nm(5D4→7F3) of Tb3+ ions. The bifunctional magnetic and fluorescence NCs will show potential applications in biomedical fields in the future.
