期刊文献+
共找到41篇文章
< 1 2 3 >
每页显示 20 50 100
An Efficient Extraction-Free Method for Oxidative Desulfurization of Model Fuels Employing Cross-Linked Polyionic Liquid Phosphotungstate Catalysts 被引量:2
1
作者 Yuan Dandan Zhang Ling +2 位作者 Yin Guoqing Wang Yuanyuan Zhang Jiaojing 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2022年第3期10-20,共11页
An efficient extraction-free oxidative desulfurization(ODS)process using a series of cross-linked polyionic liquid phosphotungstate(CLPIL-PW)catalysts is reported.The cross-linked PILs were prepared with DVB and 1-n-a... An efficient extraction-free oxidative desulfurization(ODS)process using a series of cross-linked polyionic liquid phosphotungstate(CLPIL-PW)catalysts is reported.The cross-linked PILs were prepared with DVB and 1-n-alkyl-3-vinyl imidazole hydrobromide(alkyl=ethyl,butyl,octyl,dodecyl),and were then assembled with phosphotungstic acid(H_(3)PW_(12)O_(40))to form the catalysts.The CLPIL-PWs have been applied to the oxidative removal of dibenzothiophene(DBT)from model oil with H_(2)O_(2) as an oxidant.The effects of ionic liquid(IL)cationic species,varying the DVB/IL molar ratio in the polymerization process,and varying operating conditions were investigated.The CLPIL-PWs were characterized by inductively coupled plasma(ICP)mass spectrometry,elemental analysis,scanning electron microscopy(SEM),Fourier transform infra-red(FTIR)spectroscopy,X-ray diffraction(XRD),^(13)C and^(31)P nuclear magnetic resonance(NMR)spectroscopy.The polydivinylbenzene-co-1-n-octyl-3-vinyl imidazole phosphotungstate(P(DVB-OVIm)PW)exhibited the highest DBT removal efficiency(99.9%)and remarkable recyclability,and could be reused eight times without reducing its activity.Finally,an extraction-free ODS mechanism is proposed. 展开更多
关键词 DESULFURIZATION polyionic liquids(PILs) cross-linking phosphotungstic acid oxidation reaction
下载PDF
Synthesis,characterization and antitumor activity of rare earth(Y,La) substituted phosphotungstates containing 5-fluorouracil 被引量:5
2
作者 刘霞 甘强 冯长根 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第6期604-608,共5页
Two rare earth substituted Keggin-type phosphomngstates containing 5-fluorouracil, K10C4H4FN2O2Y(PW11O39)2· 10H2O (FYPW) and Kg(C4H4FN2O2)2La(PWl1O39)2· 18H2O (FLaPW) were synthesized in aqueous so... Two rare earth substituted Keggin-type phosphomngstates containing 5-fluorouracil, K10C4H4FN2O2Y(PW11O39)2· 10H2O (FYPW) and Kg(C4H4FN2O2)2La(PWl1O39)2· 18H2O (FLaPW) were synthesized in aqueous solution, and the structures were characterized by Fourier transform infrared spectroscopy (FT-IR), element analysis, inductively coupled plasma spectrometry (ICP), X-ray powder diffraction (XRD) and 1H nuclear magnetic resonance (NMR). Thermal analysis showed that the decomposition processes of the two compounds could be di- vided into three steps, the loss of crystal water, the decomposition of 5-fluorouracil unit and the decomposition of Keggin-type polyanions. The in vitro cytotoxicities against HEK 293, HeLa and HepG-2 cells were studied by methyl thiazolyl tetrazolium (MTT) assay. The results showed that FYPW and FLaPW had higher antitumor activities than 5-fluorouracil, C4H4FN2O2H2PW12O40.8H2O and rare earth substituted polyoxometalates KllLn(PW11O39)2@nH2O (Ln-Y, La). It was concluded that introducing 5-fluorouracil and rare earth (Y or La) into its structure was a considerable way to enhance antitumor activities ofpolyoxometalates. 展开更多
关键词 phosphotungstates 5-flurouracil rare earth CYTOTOXICITY ANTITUMOR HELA HEPG-2
原文传递
Synthesis and antitumor activities of rare earth substituted phosphotungstates containing 5-fluorouracil 被引量:6
3
作者 冯长根 甘强 +1 位作者 刘霞 何洪优 《Journal of Rare Earths》 SCIE EI CAS CSCD 2012年第5期467-472,共6页
Two novel rare earth substituted phosphotungstates containing 5-fluorouracil,K 9(C 4 H 4 FN 2 O 2) 2 Nd(PW 11 O 39) 2 ·25H 2 O(FNdPW) and K 9(C 4 H 4 FN 2 O 2) 2 Ce(PW 11 O 39) 2 ·23H 2 O(FCePW),... Two novel rare earth substituted phosphotungstates containing 5-fluorouracil,K 9(C 4 H 4 FN 2 O 2) 2 Nd(PW 11 O 39) 2 ·25H 2 O(FNdPW) and K 9(C 4 H 4 FN 2 O 2) 2 Ce(PW 11 O 39) 2 ·23H 2 O(FCePW),were synthesized and characterized by elementary analysis,FT-IR spectra,X-ray powder diffraction and 1 H NMR.The thermal analysis showed that FNdPW decomposed at 210 and 493 oC,and FCePW decomposed at 223 and 471 oC,both of which had good thermal stabilities.MTT tests were performed to study the antitumor activities against HeLa cells and HepG-2 cells of FNdPW,FCePW,5-fluorouracil,C 4 H 4 FN 2 O 2 H 2 PW 12 O 40 ·8H 2 O and K 11 Ln(PW 11 O 39) 2 ·xH 2 O(Ln=Nd,Ce),and their cytotoxicities against HEK 293 cells.The results showed that FNdPW and FCePW possessed higher antitumor activities and lower cytotoxicities than those of 5-fluorouracil and C 4 H 4 FN 2 O 2 H 2 PW 12 O 40 ·8H 2 O,of which FNdPW exhibited the highest antitumor activates against HeLa cells(EC 50 =3.41×10-6 mol/L) and HepG-2 cells(EC 50 =6.24×10-6 mol/L).Thus the introduction of rare earth elements and 5-fluorouracil could significantly enhance antitumor effect of polyoxometalates. 展开更多
关键词 phosphotungstates 5-fluorouracil rare earth HeLa HepG-2 antitumor cytotoxicity
原文传递
Phosphotungstic acid immobilized on amino-functionalized TS-1 zeolite as a solid acid catalyst for the synthesis of tributyl citrate
4
作者 Pei Li Bianfang Shi +4 位作者 Junyao Shen Ran Cui Wenze Guo Ling Zhao Zhenhao Xi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期199-210,共12页
The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterif... The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic bonding.The Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the modifications.The amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid sites.The tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid sites.An optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1%(mol)was achieved at 150℃for 6 h over the HPW immobilized on amino-functionalized TS-1.The catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW. 展开更多
关键词 AMINO-FUNCTIONALIZATION Phosphotungstic acid TS-1 zeolite ESTERIFICATION Tributyl citrate
下载PDF
THE SYNTHESIS AND STRUCTURE OF BI-VACANT D AWSON PHOSPHOTUNGSTATE K_(10)Na_2H_2P_2W_(16)O_(60)·18H_2O
5
作者 吴新国 蒋安仁 《Chinese Science Bulletin》 SCIE EI CAS 1992年第5期387-390,共4页
The conclusion has been made that mono- and tri-vacant Dawson phosphotungstates (shown as P<sub>2</sub>W<sub>17</sub> and P<sub>2</sub>W<sub>15</sub>)exist. The bi-vacan... The conclusion has been made that mono- and tri-vacant Dawson phosphotungstates (shown as P<sub>2</sub>W<sub>17</sub> and P<sub>2</sub>W<sub>15</sub>)exist. The bi-vacant Dawson phosphotungstate (P<sub>2</sub>W<sub>16</sub>) which was synthesized by hydrolyzing P<sub>2</sub>W<sub>18</sub> with Na<sub>2</sub>CO<sub>3</sub> soluti on, has been reported by Contant et al., however this was soon rejected by themselves. It has also 展开更多
关键词 DAWSON STRUCTURE vacant HETEROPOLY ACID phosphotungstate
原文传递
Study on the Synthesis of Octyl Acetate by Phosphotungstate Heteropolyacid with Keggin Structure
6
作者 Han Jie-li, Li Hai-feng, Wang Zi-wei, Wu Chuan, Ren Jian-guo(School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006,China) 《复旦学报(自然科学版)》 CAS CSCD 北大核心 2007年第5期769-,775,共2页
1 Results Octyl Acetate is an important chemical material.It is widely used as solvent in many industries,such as plasterer,artificial leather,and lacquer varnish,spice and medicine industries.At the present time,it i... 1 Results Octyl Acetate is an important chemical material.It is widely used as solvent in many industries,such as plasterer,artificial leather,and lacquer varnish,spice and medicine industries.At the present time,it is prepared with acetic acid and 1-octanol in industry,by using sulfuric acid as the catalyst.This technique has many shortcomings,which include erosion of facility,many side reactions and difficulties of post-treatment.The most severe problem is its pollution to the environment[1-2],so this... 展开更多
关键词 octyl acetate phosphotungstate heteropolyacid Kaggin Structure
原文传递
Facile synthesis of efficient pentaethylenehexamine-phosphotungstic acid heterogeneous catalysts for oxidative desulfurization
7
作者 Chongfu Wu Changsheng Chen +4 位作者 Zhaoyang Qi Jie Chen Qinglian Wang Changshen Ye Ting Qiu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第11期140-147,共8页
The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be ... The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts. 展开更多
关键词 OXIDATION CATALYST DESULFURIZATION FUEL Phosphotungstic acid AMINO
下载PDF
Encapsulation of ionic liquid, phosphotungstic acid inside the nanocages of MIL-101(Cr): Effective and reusable catalyst for efficient solvent-free oxidative desulfurization from fuel oil
8
作者 Bo-Long Jiang Dong-Xu Zhang +3 位作者 Dan-Dan Yuan Yan-Guang Chen Tian-Zhen Hao Hua Song 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3865-3874,共10页
Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performanc... Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance.Successful encapsulation of phosphotungstic acid(HPW)and ionic liquid(BMImBr)inside the mesoporous cages of MIL-101(Cr)was accomplished through a combination of“bottle around ship”and“ship in bottle”methods.The obtained BMImPW@MIL-101(Cr)composite was characterized by XRD,FTIR,BET,SEM,XPS and ICP methods.Results indicated that the BMImPW@MIL-101(Cr)composites with PW^(3−) loading of 23.1–50.7 wt%were obtained,demonstrating that the“bottle around ship”method is beneficial to make full use of nanocages of MIL-101(Cr)to obtain expected high loading of active PW^(3−) .The BMImPW@MIL-101(Cr)exhibits excellent reusability with no evidence of leaching of active PW^(3−) and BMIm^(+),and well-preserved structure after successive cycles of regeneration and reuse.The significantly improved stability of BMImPW@MIL-101(Cr)as compared to HPW@MIL-101(Cr)is possibly because the leaching of the active PW^(3−) −sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm^(+)cation.The BMImPW@MIL-101(Cr)exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides.The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr)can be explained by the intimate contact of sulfides with active PW^(3−) sites owing the strong attraction of BMIm^(+)cation with the sulfides. 展开更多
关键词 Metal organic frameworks Phosphotungstic acid lonic liquids Stability Oxidative desulfurization
下载PDF
Study on the epoxidation of olefins with H_(2)O_(2)catalyzed by biquaternary ammonium phosphotungstic acid
9
作者 Zijie Zhang Qianyu Zha +3 位作者 Ying Liu Zhibing Zhang Jia Liu Zheng Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期146-154,共9页
Selective epoxidation of olefins is an important field in chemical industry.In this work,we developed a new phosphotungstic acid catalyst{[(C_8H_(17))(CH_(3))_(2)N]_(2)(CH_(2))_(3)}_(1.5){PO_(4)[WO(O_(2))_(2)]_(4)}wit... Selective epoxidation of olefins is an important field in chemical industry.In this work,we developed a new phosphotungstic acid catalyst{[(C_8H_(17))(CH_(3))_(2)N]_(2)(CH_(2))_(3)}_(1.5){PO_(4)[WO(O_(2))_(2)]_(4)}with long carbon chain and biquaternary ammonium cation.Cyclohexene could be epoxidized to cyclohexene oxide in 96.3%conversion and 98.2%selectivity.The catalyst type,solvent type,catalyst loading,initial molar ratio,temperature,cycle performance and substrate extensibility were studied and optimized,the kinetic parameters about overall reaction and unit reaction were also calculated.Dynamic light scattering analysis was carried out to explain the different catalytic performance between catalysts with different carbon chain length.This novel catalyst and the corresponding dynamics and mechanism study could probably help the industrial application on the epoxidation of cyclohexene with H_(2)O_(2). 展开更多
关键词 Epoxidation of olefins Phosphotungstic acid CYCLOHEXENE Kinetic study
下载PDF
Styrene epoxidation catalyzed by polyoxometalate/quaternary ammonium phase transfer catalysts: The effect of cation size and catalyst deactivation mechanism
10
作者 Qiongna Xiao Yuyan Jiang +3 位作者 Weiqiang Yuan Jingjing Chen Haohong Li Huidong Zheng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第3期192-201,共10页
Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quater... Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quaternary ammoniums bearing different cationic sizes,i.e.MTOA+(methyltrioctylammonium,[(C_(8)H_(17))_(3)CH_(3)N]+),HTMA+(hexadecyltrimethylammonium,[(C_(16)H_(33))(CH_(3))_(3)N]+) and DMDOA+(dimethyldioctadecylammonium,[(C_(18)H_(37))_(2)(CH_(3))_(2)N]+) were incorporated with polyoxometalate (POM) anions to prepare phase transfer catalysts (PTCs),which were used in the styrene epoxidations.Among them,(MTOA)_(3)PW_(4)O_(24)exhibits the best catalytic performance judged from the highest styrene conversion rate(52%) and styrene oxide selectivity (93%),during which the styrene epoxidation conditions were optimized.Meanwhile,the deactivation mechanism of this kind of PTCs was proposed firstly,i.e.in the case of low H_(2)O_(2) content,the oxidant can only be used in the styrene epoxidation,in which the catalyst can transform into stable Keggin-type POM.But when the content of H_(2)O_(2) is higher,the excess H_(2)O_(2) can reactivate the Keggin-type POM into active (PW_(4)O_(24))_(3)-anions,which can trigger the ring-opening polymerization of styrene oxide.Consequently,the catalyst is deactivated by adhered poly(styrene oxide)irreversibly,which was determined by NMR spectra.In this situation,the active moiety{PO_(4)[WO(O_(2))_(2)]_(4)}_(3)-in phase-transfer catalytic system can break into some unidentified species with low W/P ratio with the presence of epoxides.This work will be beneficial for the design of new PTCs in alkene epoxidation in fine chemical industry. 展开更多
关键词 Phosphotungstic acid phase-transfer CATALYST Styrene epoxidation Catalyst deactivation mechanism Cation size effect
下载PDF
Preparation,Characterization of Dawson-type Heteropoly Acid Cerium(Ⅲ) Salt and Its Catalytic Performance on the Synthesis of n-Butyl Acetate 被引量:9
11
作者 曹小华 任杰 +3 位作者 徐常龙 张康华 占昌朝 蓝健 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第5期500-506,共7页
A novel cerium(Ⅲ) salt of Dawson type tungstophosphoric acid(Ce2P2W18O62·16H2O) was prepared by doping cerous nitrate in H6P2W18O62·13H2O powder and characterized by thermogravimetry and differential therma... A novel cerium(Ⅲ) salt of Dawson type tungstophosphoric acid(Ce2P2W18O62·16H2O) was prepared by doping cerous nitrate in H6P2W18O62·13H2O powder and characterized by thermogravimetry and differential thermal analyses(TG/DTA),Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),pyridine infrared spectroscopy(Py-IR) and scanning electron microscopy(SEM).Its catalytic activity was evaluated by the probe reaction of synthesis of n-butyl acetate with acetic acid and n-butanol.The effects of various parameters such as molar ratio of n-butanol to acetic acid,reaction temperature,reaction time,and catalyst amount have been studied by single factor experiment.The results show that Ce2P2W18O62·16H2O behaved as an excellent heterogeneous catalyst in the synthesis of n-butyl acetate.The optimum synthetic conditions were determined as follows︰molar ratio of n-butanol to acetic acid at 2.0︰1.0,mass of the catalyst being 1.44% of the total reaction mixture,reaction temperature of 120 ℃ and reaction time of 150 min.Under above conditions,the conversion of acetic acid was above 97.8%.The selectivity of n-butyl acetate based on acetic acid was,in all cases,nearly 100%.The catalysts could be recycled and still exhibited high catalytic activity with 90.4% conversion after five cycles of reaction.It was found by means of TG-DTA and Py-IR that the catalyst deactivation was due to the adsorption of a complex of by-product on the active sites on catalysts surface or the catalyst loss in its separation from the products.Compared with using sulfuric acid as catalyst,the present procedure with Ce2P2W18O62·16H2O is a green productive technology due to simple process,higher yield,catalyst recycling and no corrosion for the production facilities. 展开更多
关键词 cerous phosphotungstate Dawson structure CATALYST ESTERIFICATION n-butyl acetate
下载PDF
One-pot synthesis of a hierarchical microporous-mesoporous phosphotungstic acid-HKUST-1 catalyst and its application in the selective oxidation of cyclopentene to glutaraldehyde 被引量:9
12
作者 杨新丽 乔丽明 戴维林 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第11期1875-1885,共11页
A hierarchical microporous-mesoporous metal-organic framework of HKUST-l(Cu)-encapsulated phosphotungstic acid (HPW) material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cety... A hierarchical microporous-mesoporous metal-organic framework of HKUST-l(Cu)-encapsulated phosphotungstic acid (HPW) material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cetyltrimethylammonium bromide as the supramolecular template. The addition of HPWs to the synthesis mixture of hierarchical porous HKUST-1 results in the direct encapsulation of HPWs inside the mesopores of the HKUST-1 structure, with a homogeneous distribution over the HKUST-1 crystals, which is confirmed by XRD, FT-IR, N2 adsorption, UV-Vis DRS, and TEM. FT-IR-CO adsorption experiments indicated that additional Lewis acid sites were present in the HPWs@Meso-HKUST-1 sample. The novel heterogeneous catalyst demonstrates excellent catalytic performance for the selective oxidation of cyclopentene (CPE) to glutaraldehyde CGA) using tert-butyl hydroperoxide and acetonitrile (MeCN) as the oxidant and solvent, respectively. The high activity of the catalyst is attributed to the mesostructure of the catalyst and the nature and appropriate abundance of the HPWs--being highly dispersed with the addition of Lewis sites. After a reaction for 36 h, the 30% wt% HPWs@Meso-HKUST-1 catalyst exhibits a CPE conversion of 92.5% and a high GA yield of 73%. Furthermore, the HPWs@Meso-HKUST-1 material is sufficiently stable to prevent the leaching of HPWs, and behaves as a true heterogeneous catalyst that can be repeatedly recycled without sustaining a loss of activity and selectivity in the selective oxidation of CPE. 展开更多
关键词 Metal-organic frameworks HKUST- 1 Phosphotungstic acids Cyclopentene Glutaraldehyde
下载PDF
Nano-porous Composites Based on Liquid: Synthesis, Characterization, Esterification Heteropolyacid Functionalized Ionic and Catalytic Performance in 被引量:1
13
作者 周夫东 储伟 +1 位作者 戴晓雁 罗仕忠 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第4期473-478,I0002,共7页
Fhnctionalized ionic liquid samples (bmim-PW12) were synthesized by 1-butyl-3-methyl- imidazolium bromide (bmimBr) and 12-phosphotungstic heteropolyacid (PW12). The samples were annealed at 100-450 ℃ and were c... Fhnctionalized ionic liquid samples (bmim-PW12) were synthesized by 1-butyl-3-methyl- imidazolium bromide (bmimBr) and 12-phosphotungstic heteropolyacid (PW12). The samples were annealed at 100-450 ℃ and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, thermal gravity-DTG, brunauer emmett teller, and NHa-temperature programmed desorption. The results showed that the bmim-PW12 samples were crystal and maintained intact Keggin structure. The organic parts of those samples were partly decomposed at a temperature more than 350 ℃. The sample annealed at 400 ℃ exhibited nano-porous structure, strong acidity, and excellent catalytic activity on the esterification of n-butanol with acetic acid. The higher ester yield was obtained when the mass ratio of catalyst over the reactants amount was 5% for bmim-PW12 catalyst annealed at 400 ℃. 展开更多
关键词 Ionic liquid 1-Butyl-3-methyl-imidazolium bromide Phosphotungstic heteropolyacid Annealing treatment ESTERIFICATION
下载PDF
An Organic-inorganic Hybrid Two-dimensional Bilayer Assembled from 1:2-Type[Er(α-PW11O39)2]^11–Moieties and[Cu(dap)2]^2+Linkers 被引量:1
14
作者 罗婕 宋开放 +2 位作者 赵浩哲 赵俊伟 陈利娟 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第1期39-45,共7页
A new organic-inorganic hybrid phosphotungstate-based Cu^Ⅱ-Er^Ⅲ heterometallic derivative[Cu(dap)2(H2O)][Cu(dap)2]4.5[Er(α-PW11O39)2]·4H2O(1,dap = 1,2-diaminopropane) has been hydrothermally prepared... A new organic-inorganic hybrid phosphotungstate-based Cu^Ⅱ-Er^Ⅲ heterometallic derivative[Cu(dap)2(H2O)][Cu(dap)2]4.5[Er(α-PW11O39)2]·4H2O(1,dap = 1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.1 belongs to the triclinic space group P1 with a = 13.453(3),b =20.137(4),c = 24.565(4) A,α = 103.468(4),β = 103.829(4),γ = 98.296(4)°,V= 6148.0(19) A°3,Z =2,μ = 22.212 mm^-1,GOOF = 1.030,R = 0.0744 and wR = 0.1700.Structural analysis indicates that1 exhibits a special two-dimensional double-layer structure constructed from l:2-type[Er(α-PW11O39)2]^11- moieties and[Cu(dap)2]^2+ linkers.From the topological viewpoint,1 displays a scare two-dimensional five-connected topology in which the[Er(α-PW11O39)2]^11- moieties function as the five-connected nodes.Furthermore,its thermogravimetric behavior has been studied. 展开更多
关键词 polyoxometalate heterometallic complex phosphotungstate
下载PDF
Catalytic synthesis of acetals and ketals with H3PW12O40/PAn 被引量:11
15
作者 YANG Shuijin ZHANG Yijun +1 位作者 DU Xinxian Philippe G. Merle 《Rare Metals》 SCIE EI CAS CSCD 2008年第1期89-94,共6页
A new environmental friendly catalyst H3PW12O40/PAn was prepared and identified by means of FT-IR,XRD,and TG/DTA.The optimum conditions have been found;that is,the mass ratio of PAn to H3PW12O40 is 1:1.5,the volume o... A new environmental friendly catalyst H3PW12O40/PAn was prepared and identified by means of FT-IR,XRD,and TG/DTA.The optimum conditions have been found;that is,the mass ratio of PAn to H3PW12O40 is 1:1.5,the volume of methanol is 20 mL,and the reflux reaction time is 3 h.The structural identity of Keggin units is preserved after the incorporation into polyaniline matrix.Catalytic activities of H3PW12O40/PAn in synthesizing 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,cyclohexanone ethylene ketal,cyclohexanone 1,2-propanediol ketal,butanone ethylene ketal,butanone 1,2-propanediol ketal,2-phenyl-1,3-dioxolane,4-methyl-2-phenyl-1,3-dioxolane,2-propyl-1,3-dioxolane,and 4-methyl-2-propyl-1,3-dioxolane were reported.It has been demon-strated that H3PW12O40/PAn is an excellent catalyst.Various factors concerned in these reactions were investigated.The optimum conditions are as follows:the molar ratio of aldehyde/ketone to glycol(r) is 1:1.5,the mass ratio of the catalyst used to the reactants is 0.6%,and the reaction time is 1.0 h.Under these conditions,the yield is as follows:2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,69.0%;2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,79.5%;cyclohexanone ethylene ketal,78.9%;cyclohexanone 1,2-propanediol ketal,85.3%;butanone ethylene ketal,56.9%;butanone 1,2-propanediol ketal,78.1%;2-phenyl-1,3-dioxolane,76.3%;4-methyl-2-phenyl-1,3-dioxolane,94.2%;2-propyl-1,3-dioxolane,70.7%;and 4-methyl-2-propyl-1,3-dioxolane,79.2%. 展开更多
关键词 phosphotungstic acid ACETAL KETAL POLYANILINE CATALYSIS
下载PDF
A Hybrid Membrane of Poly(vinyl alcohol) and Phosphotungstic Acid for Fuel Cells 被引量:10
16
作者 李磊 王宇新 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第5期614-617,共4页
Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embe... Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embedded are stable in the PVA matrix when the membrane is immerged in water or methanol solution atroom temperature. Conductivity of the composite membranes scatters around 10-3 S.cm-1 at room temperature.The methanol crossover through the membranes is about an order of magnitude lower than that through Nafion117 membrane. 展开更多
关键词 fuel cell proton conductor composite membrane poly(vinyl alcohol) phosphotungstic acid
下载PDF
Insight into the oxidative desulfurization of high-sulfur petroleum coke under mild conditions:a journey of vanadium-substituted Dawson-type phosphotungstic acid 被引量:8
17
作者 Fu-Min Li Ming-Qing Hua +7 位作者 Yan-Chen Wei Ji-Xing Liu Jia-Hong Gong Chao Wang Pei-Wen Wu Yan Huang Hua-Ming Li Wen-Shuai Zhu 《Petroleum Science》 SCIE CAS CSCD 2021年第3期983-993,共11页
High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we... High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we design and construct a highly efective CTAB@HPA composites to be explored for the catalytic oxidative desulfurization of HSPC under mild conditions using hydrogen peroxide as the oxidant and 1-butyl-3-methylimidazole tetrafuoroborate ionic liquid as the extractant.The results demonstrate that the sulfur content of HSPC could be strikingly reduced from 4.46 wt%to 2.48 wt%under 60℃ and atmospheric pressure,and that the organic sulfur in HSPC is mainly oxidized to sulfoxide,sulfone and sulfate,which latter can be directly separated from petroleum coke.Moreover,the efect of reaction conditions on the desulfurization performance of HSPC as well as the catalytic oxidation reaction kinetic of HSPC desulfurization was systematically investigated.Furthermore,a mechanism for the oxidative desulfurization of HSPC over CTAB@HPA catalysts was proposed.Therefore,this work provides new insight into how to construct active catalysts for the desulfurization of HSPC under mild conditions. 展开更多
关键词 High-sulfur petroleum coke Dawson-type phosphotungstic acid Oxidative desulfurization Mild conditions SULFATE
下载PDF
Synthesis of Bimodal Mesoporous TiO_(2)-PTA/BMMS and Its Enhanced Performance in the Photocatalytic Oxidative Desulfurization 被引量:8
18
作者 Yang Lina Zhang Xi +2 位作者 Cui Licheng Xu Meizhen Li Jian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2021年第3期58-68,共11页
With the bimodal mesoporous silica(BMMS)acting as the support and the composite of TiO2 with phosphotungstic acid(PTA)functioning as the active constituent,TiO_(2)-PTA/BMMS was synthesized by the two-step impregnation... With the bimodal mesoporous silica(BMMS)acting as the support and the composite of TiO2 with phosphotungstic acid(PTA)functioning as the active constituent,TiO_(2)-PTA/BMMS was synthesized by the two-step impregnation route.This catalyst was applied in the photocatalytic oxidative desulfurization(PODS)process,with dibenzothiophene serving as the model sulfur compound.PODS proceeds in one pot,in which H_(2)O_(2) acts as the oxidant and methanol plays the role of the solvent.TiO_(2)-PTA/BMMS was characterized by XRD,N_(2) adsorption and desorption,XRF,FTIR,UV-vis,SEM,EDS and TEM techniques.It showed that the introduction of PTA contributes higher order,higher surface area and pore volume to the bimodal mesoporous support.With TiO_(2)-PTA/BMMS used as the catalyst under the UV irradiation,the desulfurization rate can reach 99.6%.This result is obviously higher than that achieved by TiO_(2)/BMMS.The catalyst also has no significant drop in catalytic activity after eight runs of reusing.In such catalytic system,the synergistic effects of this photocatalytic oxidation and the extraction with the methanol serving as the solvent played an indispensable role. 展开更多
关键词 phosphotungstic acid bimodal mesoporous silica titanium dioxide photocatalytic desulfurization UV irradiation DIBENZOTHIOPHENE
下载PDF
Synergistic Effect between Zr-MOF and Phosphotungstic Acid for Oxidative Desulfurization 被引量:5
19
作者 Zong Mengya Zhao Yutong +1 位作者 Fan Cunzheng Wang Danhong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2020年第4期56-62,共7页
PTA/UiO-66 composites were successfully synthesized by the hydrothermal method.The results showed that the synergistic effect between phosphotungstic acid(PTA)and UiO-66 could enhance the oxidative desulfurization(ODS... PTA/UiO-66 composites were successfully synthesized by the hydrothermal method.The results showed that the synergistic effect between phosphotungstic acid(PTA)and UiO-66 could enhance the oxidative desulfurization(ODS)activity.The XRD results proved that UiO-66 retained its structure in the PTA/UiO-66 composites.The SEM results showed that the PTA/UiO-66 catalysts exhibited regular octahedral shape.The Raman spectra revealed that PTA in the composites retained the Keggin structure.The XPS results showed that the electron transfer occurred from Zr-MOF to PTA.The ODS reaction mechanism was discussed.Electrons transfer from Zr-MOF to PTA can promote the generation of active species(·OH)and thus enhance the ODS activity.This explanation can be confirmed by the formation of oxygen vacancy and W0 as revealed by the XPS analysis. 展开更多
关键词 phosphotungstic acid Zr-MOF oxidative desulfurization synergistic effect oxygen vacancy
下载PDF
Three-dimensionally Ordered Macroporous Phosphotungstic Acid/SiO2 for Efficient Catalytic Oxidative Desulfurization 被引量:3
20
作者 杜岳 YANG Peng +3 位作者 雷家珩 ZHOU Shiyu LI Junsheng DU Xiaodi 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第4期849-854,共6页
Three-dimensionally ordered(3DOM) macroporous phosphotungstic acid/SiO_2(HPW/SiO_2) materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization(ODS) of the model fue... Three-dimensionally ordered(3DOM) macroporous phosphotungstic acid/SiO_2(HPW/SiO_2) materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization(ODS) of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene(DBT) could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles. 展开更多
关键词 three-dimensionally ordered macroporous SiO2 phosphotungstic acid oxidativedesulfurization
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部