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1999 Volume 16 Issue 4
1999, 16(4): 1-5
Abstract:
The photoelectrochemical behavior of the nanostructure SnO2 porous film cosensitized by a cyanine dye (PMC) and cis-di(thiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(Ⅱ) dye (RuL2(SCN)2) have been investigated. The ground state level and the excited state level of the dyes were determined by cyclic voltammetry and optical absorption spectroscopy. The results showed that the excited state levels of both dyes matched the conduction band edge of SnO2 nanoparticle. The optical absorption band of PMC situates in the region of 550 to 700 nm and that of RuL2(SCN)2 in the region of 400 to 600 nm. Therefore the cosensitization of these two dyes can widen the optical absorption region. As a result, the photocurrent intensity of nanostructure SnO2 electrode was increased obviously by co-sensitization in both visible and near infra-red regions. Consequently the light-to-electricity conversion efficiency was improved evidently. The maximum value of IPCE has reached 68%.
The photoelectrochemical behavior of the nanostructure SnO2 porous film cosensitized by a cyanine dye (PMC) and cis-di(thiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(Ⅱ) dye (RuL2(SCN)2) have been investigated. The ground state level and the excited state level of the dyes were determined by cyclic voltammetry and optical absorption spectroscopy. The results showed that the excited state levels of both dyes matched the conduction band edge of SnO2 nanoparticle. The optical absorption band of PMC situates in the region of 550 to 700 nm and that of RuL2(SCN)2 in the region of 400 to 600 nm. Therefore the cosensitization of these two dyes can widen the optical absorption region. As a result, the photocurrent intensity of nanostructure SnO2 electrode was increased obviously by co-sensitization in both visible and near infra-red regions. Consequently the light-to-electricity conversion efficiency was improved evidently. The maximum value of IPCE has reached 68%.
1999, 16(4): 6-9
Abstract:
Eight title phosphonic diphenylesters have been synthesized and their structures were confirmed by 1H NMR, 31P NMR, EI-MS, IR and elemental analysis.
Eight title phosphonic diphenylesters have been synthesized and their structures were confirmed by 1H NMR, 31P NMR, EI-MS, IR and elemental analysis.
1999, 16(4): 10-13
Abstract:
The thermooxidative degradation of ethyleneoxide/tetrahydrofuran(EO/THF) copolyether-urethane in air has been investigated by FT-IR, 13C NMR and 1H NMR. It is found that the degradation of the polyether-urethane consisted of the oxidation of soft segments, depolymerization of the hard segments and the repolymerization of isocyanates with alcohols. And the soft and hard segments show influences each other during degradation that the thermooxidative stability of the soft segments is improved by crosslinking structure and hydrogen bondings in the hard segments and the degradation products of the soft segments affect the depolymerization and repolymerization of the hard segments. No obvious oxidation of the hard segments and no carbodiimide or pseudo-urea ether groups are found on degradation at 90℃.
The thermooxidative degradation of ethyleneoxide/tetrahydrofuran(EO/THF) copolyether-urethane in air has been investigated by FT-IR, 13C NMR and 1H NMR. It is found that the degradation of the polyether-urethane consisted of the oxidation of soft segments, depolymerization of the hard segments and the repolymerization of isocyanates with alcohols. And the soft and hard segments show influences each other during degradation that the thermooxidative stability of the soft segments is improved by crosslinking structure and hydrogen bondings in the hard segments and the degradation products of the soft segments affect the depolymerization and repolymerization of the hard segments. No obvious oxidation of the hard segments and no carbodiimide or pseudo-urea ether groups are found on degradation at 90℃.
Syntheses and Spectral Properties of 9'-(4-(Allyloxy) benzoxy)indolinospironaphthoxazine Derivatives
1999, 16(4): 14-19
Abstract:
Seven 9'-hydroxyindolinospironaphthoxazine derivatives(HSPa~g) and seven corresponding 9'-(4-(allyloxy)benzoxy)indolinospironaphthoxazine derivatives(ASPa~g) were synthesized. The 1H NMR results of ASPa~g showed that the chemical shifts of two protons of methene at 1-position of ASPe and ASPb are not equal and the two protons belong to AB spin system. In addition, the absorption spectra of the naphthoxazine moiety are slightly blue shifted with increase of the polarity of the solvent used. The substituents at 1-position have little effect on the absorption spectrum at 295 nm in the parent compound ASPa, and only absorption spectrum of the naphthoxazine moiety of ASPe is found to be red-shifted. A change of substitutent at 5-position, such as in the case of 5-methyl and 5-chloro derivatives, results in the red-shift of absorption band at 295 nm, but does not much influence the absorption spectrum of naphthoxazine moiety. The substituent change at 5-position affects absorption spectrum of the colored forms in the visible region and induces a bathochromic shift.
Seven 9'-hydroxyindolinospironaphthoxazine derivatives(HSPa~g) and seven corresponding 9'-(4-(allyloxy)benzoxy)indolinospironaphthoxazine derivatives(ASPa~g) were synthesized. The 1H NMR results of ASPa~g showed that the chemical shifts of two protons of methene at 1-position of ASPe and ASPb are not equal and the two protons belong to AB spin system. In addition, the absorption spectra of the naphthoxazine moiety are slightly blue shifted with increase of the polarity of the solvent used. The substituents at 1-position have little effect on the absorption spectrum at 295 nm in the parent compound ASPa, and only absorption spectrum of the naphthoxazine moiety of ASPe is found to be red-shifted. A change of substitutent at 5-position, such as in the case of 5-methyl and 5-chloro derivatives, results in the red-shift of absorption band at 295 nm, but does not much influence the absorption spectrum of naphthoxazine moiety. The substituent change at 5-position affects absorption spectrum of the colored forms in the visible region and induces a bathochromic shift.
1999, 16(4): 20-23
Abstract:
The methane oxidation to syngas on Ni/Al2O3 catalysts has been carried out on a fixed bed flow reactor. The effects of temperature of catalyst bed, system pressure, space velocity and n(CH4)/n(O2) ratio on carbon deposition on the catalyst have been investigated. The results show that the rate of carbon deposition decreased as the temperature of the catalyst bed increased and vice versa, and an obvious carbon deposition was observed at temperature near 600℃. The rate of carbon deposition also increased with increase of the system pressure and decreased with increase of the space velocity, when the latter exceeded a certain value. Based on the thermodynamic analysis of the reaction system and the experiment results, it is believed that the carbon deposition on the Ni/Al2O3 is mainly caused by reactions of 2CO→C+CO2 and CO+H2→C+H2O, but not the decomposition of methane.
The methane oxidation to syngas on Ni/Al2O3 catalysts has been carried out on a fixed bed flow reactor. The effects of temperature of catalyst bed, system pressure, space velocity and n(CH4)/n(O2) ratio on carbon deposition on the catalyst have been investigated. The results show that the rate of carbon deposition decreased as the temperature of the catalyst bed increased and vice versa, and an obvious carbon deposition was observed at temperature near 600℃. The rate of carbon deposition also increased with increase of the system pressure and decreased with increase of the space velocity, when the latter exceeded a certain value. Based on the thermodynamic analysis of the reaction system and the experiment results, it is believed that the carbon deposition on the Ni/Al2O3 is mainly caused by reactions of 2CO→C+CO2 and CO+H2→C+H2O, but not the decomposition of methane.
1999, 16(4): 24-27
Abstract:
Three long-wavelength photosensitive initiation systems composed of photosensitizer 3-acetyl-7-N,N-diethyl-aminocoumarin(KC1), 3-(4-N,N-diethylaminocinnamoyl)-7-N,N-die-thylaminocoumarin (KC2), 3-(4-N,N-dimethylaminocinnamoyl)-7-N,N-diethylaminocou-marin (KC3) respectively with photoinitiator 2-chlorohexaarylbiimidazole(o-Cl-HABI) and coinitiator n-dodecanethiol(SH) have been studied. The relationship between the photopolymerization rate of MMA under visible light and concentration of KC1, o-Cl-HABI and SH in a system has veen examined by dilatometry. Good images in offset printing was obtained when the studied systems were irradiatied by visible light.
Three long-wavelength photosensitive initiation systems composed of photosensitizer 3-acetyl-7-N,N-diethyl-aminocoumarin(KC1), 3-(4-N,N-diethylaminocinnamoyl)-7-N,N-die-thylaminocoumarin (KC2), 3-(4-N,N-dimethylaminocinnamoyl)-7-N,N-diethylaminocou-marin (KC3) respectively with photoinitiator 2-chlorohexaarylbiimidazole(o-Cl-HABI) and coinitiator n-dodecanethiol(SH) have been studied. The relationship between the photopolymerization rate of MMA under visible light and concentration of KC1, o-Cl-HABI and SH in a system has veen examined by dilatometry. Good images in offset printing was obtained when the studied systems were irradiatied by visible light.
1999, 16(4): 28-32
Abstract:
Title compound(HNQ) has been catalytically synthesized from 1- and 2-naphthol over metalloporphyrins in methanol solution of NaOH using hydroperoxide as an oxidant with maximum yield of 40% and 57%, respectively. The method is characteristic of low reaction temperature, high conversion of naphthol, strong alkali medium, easy operation and high yield of the products.
Title compound(HNQ) has been catalytically synthesized from 1- and 2-naphthol over metalloporphyrins in methanol solution of NaOH using hydroperoxide as an oxidant with maximum yield of 40% and 57%, respectively. The method is characteristic of low reaction temperature, high conversion of naphthol, strong alkali medium, easy operation and high yield of the products.
1999, 16(4): 33-36
Abstract:
Polymer nanoparticles were prepared by emulsion polymerization and characterized by TEM, XRD, FT-IR, DSC and TGA. Their tribological properties as lubricating oil additives have been evaluated. The results show that the crosslinking degree and core/shell structure of the polymer nanoparticles affect the tribological behavior, and under middle-low load, proper concentration and crosslinking, the polymer nanoparticles show good anti-wear and anti-friction properties.
Polymer nanoparticles were prepared by emulsion polymerization and characterized by TEM, XRD, FT-IR, DSC and TGA. Their tribological properties as lubricating oil additives have been evaluated. The results show that the crosslinking degree and core/shell structure of the polymer nanoparticles affect the tribological behavior, and under middle-low load, proper concentration and crosslinking, the polymer nanoparticles show good anti-wear and anti-friction properties.
1999, 16(4): 37-40
Abstract:
Ce(SO4)2·xH2O was prepared by hot impregnation method from CeO2 and hot concentrated H2SO4 and mixed with CuSO4·yH2O to give composite catalysts.In syntheses of isopenty l acetate and dibutyl phthalate at optimum conditions the composite cataly sts gave conversion of the corresponding carboxy lic acids 63.2% and 68.8%, respectively. The cataly tic activity of the composite catalysts has been discussed in terms of the orbit structure of the sufficient energy-level of rare earth and transition metal ions and Brönsteds acid-base theory.
Ce(SO4)2·xH2O was prepared by hot impregnation method from CeO2 and hot concentrated H2SO4 and mixed with CuSO4·yH2O to give composite catalysts.In syntheses of isopenty l acetate and dibutyl phthalate at optimum conditions the composite cataly sts gave conversion of the corresponding carboxy lic acids 63.2% and 68.8%, respectively. The cataly tic activity of the composite catalysts has been discussed in terms of the orbit structure of the sufficient energy-level of rare earth and transition metal ions and Brönsteds acid-base theory.
1999, 16(4): 41-46
Abstract:
The 1-aroyl-4-[1'-N-2',3',4',6'-tetra-O-acetyl-β-D-glucopyranosyl] thiosemicarbazides (6) and seven 1-aroyl-4-[1'-N-2',3',4'-tri-O-acetyl-β-D-xylopyranosyl] thiosemicarbazides(7) were synthesized by condensation of 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (3) and 2,3,4-tri-O-acetyl-β-D-xylopyranosyl isothiocyanate(4) with aroyl hydrazines(5) in 95% EtOH under reflux, respectively, and also 1-aroyl-4-[1'-N-β-D-glucopyranosyl and corre sponding 1'-N-β-D-xylopyranosyl] thiosemicarbazides(8,9) after deacetylation. The structures of the compounds were confirmed by elemental and spectral analyses.
The 1-aroyl-4-[1'-N-2',3',4',6'-tetra-O-acetyl-β-D-glucopyranosyl] thiosemicarbazides (6) and seven 1-aroyl-4-[1'-N-2',3',4'-tri-O-acetyl-β-D-xylopyranosyl] thiosemicarbazides(7) were synthesized by condensation of 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (3) and 2,3,4-tri-O-acetyl-β-D-xylopyranosyl isothiocyanate(4) with aroyl hydrazines(5) in 95% EtOH under reflux, respectively, and also 1-aroyl-4-[1'-N-β-D-glucopyranosyl and corre sponding 1'-N-β-D-xylopyranosyl] thiosemicarbazides(8,9) after deacetylation. The structures of the compounds were confirmed by elemental and spectral analyses.
1999, 16(4): 47-51
Abstract:
The catalytic performance of Mo-S-K-based catalysts prepared with different precursors for synthesis of methanthiol from high H2S containing syngas has been investigated. The effects of the promotors K2CO3, KCl and KF on the activity of the catalyst under various temperature and pressure conditions have been examined. The results show that MoS2/K2CO3/γ-Al2O3 catalyst prepared with precursor (NH4)2MoS4 was found to have the same catalytic behavoir as that prepared from K2MoS4. XRD measurements indicate the existence of a new Mo-S-K phase (2θ=29.8° and 30.8°) in the catalyst both of MoS2/K+/γ-Al2O3 promoted by weak basic potassium salts (K2CO3 and KF) and of K2MoS4/γ-Al2O3 respectively.
The catalytic performance of Mo-S-K-based catalysts prepared with different precursors for synthesis of methanthiol from high H2S containing syngas has been investigated. The effects of the promotors K2CO3, KCl and KF on the activity of the catalyst under various temperature and pressure conditions have been examined. The results show that MoS2/K2CO3/γ-Al2O3 catalyst prepared with precursor (NH4)2MoS4 was found to have the same catalytic behavoir as that prepared from K2MoS4. XRD measurements indicate the existence of a new Mo-S-K phase (2θ=29.8° and 30.8°) in the catalyst both of MoS2/K+/γ-Al2O3 promoted by weak basic potassium salts (K2CO3 and KF) and of K2MoS4/γ-Al2O3 respectively.
1999, 16(4): 52-54
Abstract:
(Ni-Co)-WC composite electrode was prepared by composite electrodeposition method. Its electrocatalytic property for hydrogen evolution reaction in weak acidic, basic and neutral media and electrochemical stability in weak acidic solution have been investigated. The composite electrode showed an excellent electrocatalytic property for hydrogen evolution reaction and good electrochemical stability.
(Ni-Co)-WC composite electrode was prepared by composite electrodeposition method. Its electrocatalytic property for hydrogen evolution reaction in weak acidic, basic and neutral media and electrochemical stability in weak acidic solution have been investigated. The composite electrode showed an excellent electrocatalytic property for hydrogen evolution reaction and good electrochemical stability.
1999, 16(4): 55-57
Abstract:
A mixedalkyl(C8~C13) bonded silica for reversed-phase liquid chromatography was prepared through the reaction of alkyl(C8~C13) triethoxysilanes with silica of average particle size 5 μm and surface area 210 m2/g. The carbon content of the mixedalkyl bonded silica was 5.21% by elemental analysis. The effects of the fixed phase on the chromatographic separation of polycyclic aromatic hydrocarbons and aromatic substituent isomers have been investigated.
A mixedalkyl(C8~C13) bonded silica for reversed-phase liquid chromatography was prepared through the reaction of alkyl(C8~C13) triethoxysilanes with silica of average particle size 5 μm and surface area 210 m2/g. The carbon content of the mixedalkyl bonded silica was 5.21% by elemental analysis. The effects of the fixed phase on the chromatographic separation of polycyclic aromatic hydrocarbons and aromatic substituent isomers have been investigated.
1999, 16(4): 58-61
Abstract:
Ammonium ion selective electrode and flow analysis are combined to determine ammonia in the hollow fiber membrane extraction of Er(Ⅲ) and Yb(Ⅲ) with ammoniated HBTMPP(bis(2,4,4-trimethylpentyl)phosphonic acid). At the optimum conditions of analysis: concentration of NaOH 0.02 mol/L, stagant time 90 s there is a linear response from 2.0×10-5 to 1.0×10-1 mol/L for ammonium ion. In this method only 0.5 mL feed solution is needed instead of 3.0 mL in classical method and the sampling rate is 15/h. The H+ still transfers first in feed solution of high pH when ammoniated HBTMPP is used and the pH value of the feed solution decreases quickly. Then a mixing exchange between H+ and NH4+ occurs. The pH of the feed solution keeps constant owing to the buffer formation in it. The same ion transfer behavior is found when extraction and stripping are carried out simuetaneously.
Ammonium ion selective electrode and flow analysis are combined to determine ammonia in the hollow fiber membrane extraction of Er(Ⅲ) and Yb(Ⅲ) with ammoniated HBTMPP(bis(2,4,4-trimethylpentyl)phosphonic acid). At the optimum conditions of analysis: concentration of NaOH 0.02 mol/L, stagant time 90 s there is a linear response from 2.0×10-5 to 1.0×10-1 mol/L for ammonium ion. In this method only 0.5 mL feed solution is needed instead of 3.0 mL in classical method and the sampling rate is 15/h. The H+ still transfers first in feed solution of high pH when ammoniated HBTMPP is used and the pH value of the feed solution decreases quickly. Then a mixing exchange between H+ and NH4+ occurs. The pH of the feed solution keeps constant owing to the buffer formation in it. The same ion transfer behavior is found when extraction and stripping are carried out simuetaneously.
1999, 16(4): 62-65
Abstract:
The enzyme activities of lignin peroxidase(LiP) and Mn-dependent perosidase(MnP) in a microemulsion consisted of CTAB, n-heptane, cyclohexane in sodium dihydrogen phosphate were found to be increased by 82.15% and 57.90%, respectively as compared in single sodium tartrate buffer solution.
The enzyme activities of lignin peroxidase(LiP) and Mn-dependent perosidase(MnP) in a microemulsion consisted of CTAB, n-heptane, cyclohexane in sodium dihydrogen phosphate were found to be increased by 82.15% and 57.90%, respectively as compared in single sodium tartrate buffer solution.
1999, 16(4): 66-69
Abstract:
Nanosize LiCoO2 was synthesized by sol-gel method, characterized and tested by XRD, TG-DTA, BET and ICP measurements. The sample sized in ca. 30 nm with low impurity was obtained. Their electrochemical behavior have been studied by constant current charge/discharge, cyclic voltammetry and AC impedance techniques. The results show that the nanosize LiCoO2 has a larger initial discharge capacity, better cyclic stability and higher discharge voltage than common LiCoO2. The mixture of nano LiCoO2 with common LiCoO2 in optimum weight ratio showed an improved cyclic stability.
Nanosize LiCoO2 was synthesized by sol-gel method, characterized and tested by XRD, TG-DTA, BET and ICP measurements. The sample sized in ca. 30 nm with low impurity was obtained. Their electrochemical behavior have been studied by constant current charge/discharge, cyclic voltammetry and AC impedance techniques. The results show that the nanosize LiCoO2 has a larger initial discharge capacity, better cyclic stability and higher discharge voltage than common LiCoO2. The mixture of nano LiCoO2 with common LiCoO2 in optimum weight ratio showed an improved cyclic stability.
1999, 16(4): 70-73
Abstract:
The functions of several gas additives: hydrogen, nitrogen, helium, carbon dioxide and oxygen on the dehydrogenative coupling of methane under pulse corone plasma at ambient temperature and atmospheric pressure have been examined. The results showed that hydrogen has hardly any influences on the coupling of methane. Nitrogen and helium are helpful to the formation of ethane and ethylene and restrain the acetylene formation to a certain degree. Acetylene remains as the main component (>75%) among C2 products. Increasing the ratio of carbon dioxide to methane causes an increase of methane conversion, whereas C2H2 selectivity decreases dramatically after a relative stable region and the C2H6 and C2H4 selectivities show little change. The C2 yield exibits a maximum at a CO2/CH4 ratio of 0.2. Increasing the ratio of oxygen to methane increases the methane conversion but C2 yield only slightly increases at O2/CH4 ratio less than 0.16.
The functions of several gas additives: hydrogen, nitrogen, helium, carbon dioxide and oxygen on the dehydrogenative coupling of methane under pulse corone plasma at ambient temperature and atmospheric pressure have been examined. The results showed that hydrogen has hardly any influences on the coupling of methane. Nitrogen and helium are helpful to the formation of ethane and ethylene and restrain the acetylene formation to a certain degree. Acetylene remains as the main component (>75%) among C2 products. Increasing the ratio of carbon dioxide to methane causes an increase of methane conversion, whereas C2H2 selectivity decreases dramatically after a relative stable region and the C2H6 and C2H4 selectivities show little change. The C2 yield exibits a maximum at a CO2/CH4 ratio of 0.2. Increasing the ratio of oxygen to methane increases the methane conversion but C2 yield only slightly increases at O2/CH4 ratio less than 0.16.
1999, 16(4): 74-76
Abstract:
A novel chiral amino alcohol ligand, (1R,2R,5S,7R,8R,9S)-9-amino-8-hydroxycedrane was synthesized from cedranediol and reacted with borane to form the corresponding complex, oxazaborolidine, that was used as catalyst in the asymmetric reduction of prochiral ketones. Medium stereoselectivities were obtained.
A novel chiral amino alcohol ligand, (1R,2R,5S,7R,8R,9S)-9-amino-8-hydroxycedrane was synthesized from cedranediol and reacted with borane to form the corresponding complex, oxazaborolidine, that was used as catalyst in the asymmetric reduction of prochiral ketones. Medium stereoselectivities were obtained.
1999, 16(4): 77-79
Abstract:
The stability constants of ternary complexes of Gd(Ⅲ) with citric(L-aspartic) acid and L-serine(L-threonine) under the synthetic biological conditions of temperature and background electrolyte (37℃, 0.15 mol/L NaCl) were obtained by potentiometric titration. The distributions of Gd(Ⅲ) species in these systems have been discussed.
The stability constants of ternary complexes of Gd(Ⅲ) with citric(L-aspartic) acid and L-serine(L-threonine) under the synthetic biological conditions of temperature and background electrolyte (37℃, 0.15 mol/L NaCl) were obtained by potentiometric titration. The distributions of Gd(Ⅲ) species in these systems have been discussed.
1999, 16(4): 80-82
Abstract:
The hydrogenated diamond-like carbon(DLC) films were formed on conductive glass substrate by deposition in DMF using a pulse-modulated source. The X-ray photoelectron spectroscopy results of the films showed that the main composition of the films are carbon. The Raman and IR spectra indicated the existence of hydrogen in form of sp3 C in the film. From the Raman spectra indicated the formation of DLC in most regions of the film and also possible diamond deposits. The films showed high transmission ratio (>70%) in 330~2000 nm and electrical resistivity of 1010Ω·cm.
The hydrogenated diamond-like carbon(DLC) films were formed on conductive glass substrate by deposition in DMF using a pulse-modulated source. The X-ray photoelectron spectroscopy results of the films showed that the main composition of the films are carbon. The Raman and IR spectra indicated the existence of hydrogen in form of sp3 C in the film. From the Raman spectra indicated the formation of DLC in most regions of the film and also possible diamond deposits. The films showed high transmission ratio (>70%) in 330~2000 nm and electrical resistivity of 1010Ω·cm.
1999, 16(4): 83-85
Abstract:
Two novel reactive monomers 2,4-bis(2-allyl phenoxy)-6-N,N-dialkylamino-1,3,5-triazine (alkyl=methyl, ethyl) were synthesized in one-pot reaction of cyanuric chloride, 2-allyl-phenol with dialkylamine in acetone/water in the presence of aq. NaOH. The products have been characterized by FTIR, 1H NMR, 13C NMR and elemental analysis.
Two novel reactive monomers 2,4-bis(2-allyl phenoxy)-6-N,N-dialkylamino-1,3,5-triazine (alkyl=methyl, ethyl) were synthesized in one-pot reaction of cyanuric chloride, 2-allyl-phenol with dialkylamine in acetone/water in the presence of aq. NaOH. The products have been characterized by FTIR, 1H NMR, 13C NMR and elemental analysis.
1999, 16(4): 86-88
Abstract:
The catalytic activity of cuprous chloride with promotor H for synthesis of methanol and methyl formate(MF) at low temperature in a batched slurry reactor have been investigated by examining the effects of pressure, temperature and catalyst concentration as well as promotor concentration. The results indicate that the catalytic activity increases as the reaction pressure is raised and decreases with the increase of the reaction temperature. Both the catalytic activity and methanol selectivity increase, but MF selectivity decreases with the increases of the catalyst concentration. Addition of the promoter increases the activity of the catalyst with considerable decrease of the MF selectivity.
The catalytic activity of cuprous chloride with promotor H for synthesis of methanol and methyl formate(MF) at low temperature in a batched slurry reactor have been investigated by examining the effects of pressure, temperature and catalyst concentration as well as promotor concentration. The results indicate that the catalytic activity increases as the reaction pressure is raised and decreases with the increase of the reaction temperature. Both the catalytic activity and methanol selectivity increase, but MF selectivity decreases with the increases of the catalyst concentration. Addition of the promoter increases the activity of the catalyst with considerable decrease of the MF selectivity.
1999, 16(4): 89-90
Abstract:
An interfacial method of synthesizing the complexes of titanocene with substituted salicylic acid is reported. The complexes are characterized by elemental analysis, IR and 1H NMR spectra. According to the spectroscopic data, it is suggested that the hydroxyl and carboxyl oxygen in substituted salicylic acid are bound to Ti of titanocene forming hexacyclic compound.
An interfacial method of synthesizing the complexes of titanocene with substituted salicylic acid is reported. The complexes are characterized by elemental analysis, IR and 1H NMR spectra. According to the spectroscopic data, it is suggested that the hydroxyl and carboxyl oxygen in substituted salicylic acid are bound to Ti of titanocene forming hexacyclic compound.
1999, 16(4): 91-93
Abstract:
The title organic inorganic hybrid composite has been prepared by a sol-gel method from allyl alcohol and tetraethoxysilicane. The IR spectra, thermal property and impact strength of the composite are reported.
The title organic inorganic hybrid composite has been prepared by a sol-gel method from allyl alcohol and tetraethoxysilicane. The IR spectra, thermal property and impact strength of the composite are reported.
1999, 16(4): 94-96
Abstract:
The TiO2/SiO2 coating particles have been prepared by a sol-gel method with Ti(OC4H9)4 and SiO2 as precursors. The IR results indicate the existence of Si-O-Ti bonds on the catalyst. The crystalline phase of coating thin films(TiO2) was studied by XRD. The amount of TiO2 bound to the SiO2 was determined by spectrophotometry. The TiO2/SiO2 can be used repeatedly and shows a higher photocatalytic decomposition rate for dichlorvos than TiO2.
The TiO2/SiO2 coating particles have been prepared by a sol-gel method with Ti(OC4H9)4 and SiO2 as precursors. The IR results indicate the existence of Si-O-Ti bonds on the catalyst. The crystalline phase of coating thin films(TiO2) was studied by XRD. The amount of TiO2 bound to the SiO2 was determined by spectrophotometry. The TiO2/SiO2 can be used repeatedly and shows a higher photocatalytic decomposition rate for dichlorvos than TiO2.
1999, 16(4): 97-99
Abstract:
The TG and DTA results showed that the metal components in clay such as of Fe, Co, Mn and Cu catalyze the thermal degradation of clay-rubber masterbatch.
The TG and DTA results showed that the metal components in clay such as of Fe, Co, Mn and Cu catalyze the thermal degradation of clay-rubber masterbatch.
1999, 16(4): 100-101
Abstract:
Four title complexes have been synthesized and their constitutional formula characterized by elemental analysis, MS, IR and 1H NMR to be [C5H4C(CH3)(C3H7)CH2CH=CH2] LnCl2·MgCl2·THF (Ln=La,Nd,Sm,Gd).
Four title complexes have been synthesized and their constitutional formula characterized by elemental analysis, MS, IR and 1H NMR to be [C5H4C(CH3)(C3H7)CH2CH=CH2] LnCl2·MgCl2·THF (Ln=La,Nd,Sm,Gd).
1999, 16(4): 102-104
Abstract:
LiCoO2 for cathode of lithium ion battery has been prepared by evaporating a mixture solution of Li2CO3 and Co(CH3COO)2·4H2O in molar ratio of 1:2 and sintering at different temperatures. The XRD, SEM and electrochemical measurements showed that the product obtained from sintering at 800℃ for 6 hours has regular spheroid distribution, small size and the best electrochemical property.
LiCoO2 for cathode of lithium ion battery has been prepared by evaporating a mixture solution of Li2CO3 and Co(CH3COO)2·4H2O in molar ratio of 1:2 and sintering at different temperatures. The XRD, SEM and electrochemical measurements showed that the product obtained from sintering at 800℃ for 6 hours has regular spheroid distribution, small size and the best electrochemical property.
1999, 16(4): 105-107
Abstract:
Polyacrylamide coating was formed on aluminium cathode by in situ electrochemical polymerization at constant potential. The influences of supporting electrolytes, cell potential and monomer concentration on the performance and morphology of the coating have been studied. Coating with thickness up to 10 μm were obtained by polymerization of acrylamide solution containing 0.05 mol/L AlCl3 for 1 h at potential of 8.0 V. The morphology and structure of the coating have been examined by FTIR. The mechanism of ECP has been discussed briefly.
Polyacrylamide coating was formed on aluminium cathode by in situ electrochemical polymerization at constant potential. The influences of supporting electrolytes, cell potential and monomer concentration on the performance and morphology of the coating have been studied. Coating with thickness up to 10 μm were obtained by polymerization of acrylamide solution containing 0.05 mol/L AlCl3 for 1 h at potential of 8.0 V. The morphology and structure of the coating have been examined by FTIR. The mechanism of ECP has been discussed briefly.
1999, 16(4): 108-110
Abstract:
The Co-WC composite-coating electrode was prepared by electrolytic composite deposition. Its electrocatalytic activity in hydrogen evolution has been examined in a 7 mol/L KOH solution by steady-state polarization and AC impedance technology. The results show that the composite-coating is catalytically more active than Co electrode due to the increase in its real surface areas and the decrease in the standard free energy of activation. The electrode shows an excellent stability in long-term electrolysis and good resistance against power interruption.
The Co-WC composite-coating electrode was prepared by electrolytic composite deposition. Its electrocatalytic activity in hydrogen evolution has been examined in a 7 mol/L KOH solution by steady-state polarization and AC impedance technology. The results show that the composite-coating is catalytically more active than Co electrode due to the increase in its real surface areas and the decrease in the standard free energy of activation. The electrode shows an excellent stability in long-term electrolysis and good resistance against power interruption.
1999, 16(4): 111-113
Abstract:
The TPR experiments and DTA-TG results showed that catalyst Pt-Sn-K/Al2O3 had a better selectivity(94.60%) and yield(48.71%) for isobutane dehydrogenation than Pt-Sn/Al2O3.
The TPR experiments and DTA-TG results showed that catalyst Pt-Sn-K/Al2O3 had a better selectivity(94.60%) and yield(48.71%) for isobutane dehydrogenation than Pt-Sn/Al2O3.
1999, 16(4): 114-116
Abstract:
The synergistic extraction of lanthanide ions(La3+, Pr3+, Nd3+, Gd3+, Dy3+) by mixture of title butanedione compound (H2BPMPBD or H2A) with 4-hydroxyantipyrine(HAP) from nitric acid solution has been studied. The synergistic coefficient for La3+ was 9.01. The composition of the extracted compound was shown to be LaA·HA·HAP. The pH1/2 values for La3+, Pr3+, Nd3+, Gd3+ and Dy3+ were 3.95, 3.44, 3.20, 3.06 and 2.74, respectively. The extraction equilibrium constants, enthalpy change and entropy change of the reaction also have been calculated.
The synergistic extraction of lanthanide ions(La3+, Pr3+, Nd3+, Gd3+, Dy3+) by mixture of title butanedione compound (H2BPMPBD or H2A) with 4-hydroxyantipyrine(HAP) from nitric acid solution has been studied. The synergistic coefficient for La3+ was 9.01. The composition of the extracted compound was shown to be LaA·HA·HAP. The pH1/2 values for La3+, Pr3+, Nd3+, Gd3+ and Dy3+ were 3.95, 3.44, 3.20, 3.06 and 2.74, respectively. The extraction equilibrium constants, enthalpy change and entropy change of the reaction also have been calculated.
