离子液体中杂多酸季铵盐催化氧化汽油脱硫研究

将二苯并噻吩(DBT)溶于正辛烷配制成模拟汽油(硫含量500μg/g),以磷钼钒杂多酸季铵盐[(CH3)4N]4PMo11VO40为催化剂,离子液体[BMIM]PF6为萃取剂,H2O2为氧化剂,考察了催化剂用量、双氧水用量、反应温度、反应时间和硫化物种类对模拟汽油脱硫率的影响,并探讨了催化氧化脱硫机理。结果表明:当催化剂用量为0.02g/mL油、双氧水用量n(H2O2)/n(S)=4、反应温度60℃、反应时间60min和离子液体[BMIM]PF6体积为1mL时,催化氧化脱硫体系[(CH3)4N]4PMo11VO40/[BMIM]PF6/H2O2对含DBT的模拟汽油的脱硫率可达97.8%,该体系对不同硫化物脱硫率大小顺序为DBT4,6-DMDBTBT。在最佳工艺条件下,考察了该体系对FCC汽油的脱硫效果,脱硫后FCC汽油的硫含量为8.6μg/g,符合国Ⅴ汽油标准。该体系可循环使用,循环使用6次后,脱硫率没有明显降低。     

磷钨杂多酸离子液体在模拟汽油催化氧化脱硫中的应用

制备了磷钨杂多酸离子液体[BMIM]_3PW_(12)O_(40)、[BMIM]_3PMo_(12)O_(40)和[MIMPS]_3PW_(12)O_(40),以它们为催化剂,分别以离子液体[BMIM]PF_6和[BMIM]BF_4为萃取剂,30%H_2O_2为氧化剂,考察了不同脱硫体系对模拟汽油中二苯并噻吩(DBT)的脱除效果。其中,在催化氧化萃取耦合脱硫体系[MIMPS]_3PW_(12)O_(40)/[BMIM]PF_6/H_2O_2中,模拟汽油中DBT的脱除效果最好。在该脱硫体系中,考察了反应时间、反应温度、双氧水用量和催化剂用量对模拟汽油脱硫率的影响。     

离子液体中FCC模拟汽油相转移催化氧化脱硫研究

合成了一种磷钨杂多酸季铵盐[CTMA]3PW12O40,以此为相转移催化剂,离子液体[Omim]PF6为萃取剂,构建了[CTMA]3PW12O40/[Omim]PF6/H2O2催化氧化萃取耦合脱硫体系,用于脱除FCC模拟汽油中二苯并噻吩(DBT)。考察了双氧水用量、反应温度、反应时间和催化剂用量对DBT脱除效果的影响,结果表明:当双氧水用量n(H2O2)/n(S)=4、反应温度T=60℃、反应时间t=90min、催化剂用量n(催化剂)/n(S)=1∶10、萃取剂[Omim]PF6用量为1mL时,该脱硫体系中DBT脱除率可达96.9%。     

磷钨杂多酸盐催化制备生物柴油

以离子液体和磷钨酸为原料,制得3种磷钨杂多酸盐杂化材料[BMIM]3PW12O40、[PyPS]3PW12O40和[MIMPS]3PW12O40,对比研究了这3种催化剂在棕榈油和甲醇酯交换催化制备生物柴油中的催化性能,筛选出催化性能最好的[MIMPS]3PW12O40。以[MIMPS]3PW12O40为催化剂,考察了醇油物质的量比、反应时间、反应温度和催化剂用量对生物柴油收率的影响。结果表明:在醇油物质的量比为10、反应时间为6h、反应温度为65℃、催化剂用量为4%条件下,生物柴油收率可达95.2%,[MIMPS]3PW12O40催化剂易于回收,循环使用性能较好。     

杂多酸离子液体负载氨基化Fe3O4磁性复合材料的制备及其超声辅助催化脱硫性能

以N-甲基咪唑、溴代正丁烷、磷钨酸为原料制备了1-丁基-3-甲基咪唑磷钨酸离子液体[BMIM]₃PW₁₂O₄₀,将其通过超声浸渍法负载于氨基化Fe₃O₄（Fe₃O₄-NH₂）,得到枣糕型结构的[BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料,通过FTIR、XRD、XPS、TEM、振动样品磁强计（VSM）、SEM等对其组成、形貌等进行表征。以[BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料为催化剂,以H₂O₂为氧化剂,催化氧化以二苯并噻吩为硫源的正辛烷模拟油样,通过单因素法分别考察了超声时间、H₂O₂用量、反应温度和催化剂用量等因素对脱硫效果的影响,并初步探讨了[BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料催化脱硫机制。结果表明:0.5 g/L[BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料超声辅助催化氧化浓度为500 mg/g模拟油样,在323 K下H₂O₂与二苯并噻吩的摩尔比n（O）:n（S）为8:1经超声10 min时,催化脱硫率达到最佳,为88.13%;重复使用5次后,[BMIM]₃PW₁₂O₄₀/Fe₃O₄-NH₂磁性复合材料对模拟油样的催化降解率仅下降了2.51%。说明该材料具有良好的催化脱硫性能,并可重复使用。催化机制初步研究表明,活性中心可能为杂多酸阴离子、Fe₃O₄-NH₂和离子液体分别起到载体和协同增容作用。      

K3[Fe(CN)6]浓度对PEO法制备硫改性Fe3O4膜层结构和降解性能的影响

为了提高铁基类Fenton催化剂的活性,利用等离子体电解氧化法在钛合金上制备出了硫改性Fe3O4膜层类Fenton催化剂,研究了电解液中铁源K3[Fe(CN)6]的浓度对膜层的结构组成和降解苯酚性能的影响.采用SEM、EDS和XRD对催化剂的表面形貌和相组成进行了表征,以苯酚为目标降解物评价其类Fenton催化活性.结果 发现:增加电解液中K3[Fe(CN)6]的浓度,膜层内Fe3O4组分增多,含硫基团减少,膜层表面孔洞的孔径大小和数目也会发生改变.苯酚降解试验表明硫改性Fe3O4膜层在近中性条件下具有良好的催化活性.     

纳米Au／Fe2O3-MOx催化剂的制备及低温催化氧化CO的研究

用沉积-沉淀法制备了纳米Au/Fe2O3-MOx(M=La和Ce)系列催化剂,考察了催化剂对于CO的低温催化氧化性能,并通过XRD,BET和AAS等表征手段对催化剂进行了表征,分析了稀土氧化物的掺杂对Au/FezO3催化剂性能的影响.结果表明:CeO2的加入能够有效提高Au/Fe2O3催化剂的催化活性,而La2O3的加入对催化剂性能没有明显的影响.     

阴离子交换树脂负载铁取代杂多酸可见光催化降解罗丹明B

将Keggin型铁取代杂多酸阴离子PW11O39Fe(Ⅲ)(H2O)4-(PW11Fe)通过离子交换作用负载在阴离子交换树脂D301R上,制备了负载型光催化剂PW11Fe/D301R,并用于可见光催化降解水溶液中有机染料污染物罗丹明B(RhB),考察了罗丹明B的初始浓度、催化剂用量、pH值以及不同阴离子对光催化降解效果的影响。实验结果表明,当催化剂用量为0.5g时,200W金卤灯照射0.01mmol/L RhB水溶液30min,RhB的降解率可达100%,为高效利用太阳光能去除水体有机染料污染物提供了一条可供选择的新途径。     

离子液体中模拟汽油催化氧化脱硫研究

构建了[C16H33N(CH3)3]FeCl4/[BMIM]BF4/H2O_2催化氧化脱硫体系,考察了在该催化氧化脱硫体系中,模拟汽油中二苯并噻吩(DBT)的脱硫效果。结果表明,当反应温度为30℃、反应时间为60min、催化剂用量为1.5%、氧化剂用量为n(H2O_2)/n(S)=8时,模拟汽油中DBT脱硫率可达95.6%。在相同脱硫工艺条件下,还对苯并噻吩(BT)和噻吩(TS)的脱硫效果进行了研究。结果表明,该体系对不同种类硫化物的脱硫率大小顺序为DBTBTTS。该体系重复使用5次后,模拟汽油的脱硫率没有明显降低,说明其有较好的重复使用能力。该体系能在温和条件下得到较高脱硫率,是一种性能优良的氧化脱硫体系。     

纳米Au/Fe_2O_3-MO_x催化剂的制备及低温催化氧化CO的研究EI北大核心

用沉积-沉淀法制备了纳米Au/Fe2O3-MOx(M=La和Ce)系列催化剂,考察了催化剂对于CO的低温催化氧化性能,并通过XRD,BET和AAS等表征手段对催化剂进行了表征,分析了稀土氧化物的掺杂对Au/Fe2O3催化剂性能的影响。结果表明:CeO2的加入能够有效提高Au/Fe2O3催化剂的催化活性,而La2O3的加入对催化剂性能没有明显的影响。     

可见光下磷钨酸盐光催化降解分散蓝130的研究

用磷钨酸分别与可溶性盐反应合成了三种磷钨酸盐(磷钨酸钾、磷钨酸铵和磷钨酸铯),采用XRD及TG对样品进行表征,结果表明,磷钨酸盐保持着Keggin结构的稳定性,且热稳定性能良好。考察了制备得到的磷钨酸盐在可见光照射下对分散蓝130的光催化降解性能,实验表明,磷钨酸钾的最佳活化温度为300℃,而磷钨酸铵和磷钨酸铯则无需活化即具有较好的光催化降解性能。在三种磷钨酸盐中,磷钨酸铵的光催化降解性能最好,其中,当磷钨酸铵的最佳投加浓度为6g/L、双氧水最佳浓度为0.048%时,无需活化的磷钨酸铵对阴离子染料分散蓝130的光降解率可达55%以上,回收重复使用5次后,光降解率仍可达到56.5%,催化剂可以循环使用且性能良好。     

H_3PW_(12)O_(40)/PMMA/PA6夹层复合纳米纤维膜的制备及光催化性能

采用静电纺丝法制备了磷钨酸(H_3PW_(12)O_(40))/聚甲基丙烯酸甲酯(PMMA)/尼龙6(PA6)夹层复合纳米纤维膜,并通过扫描电镜、X射线能谱和红外光谱对其形貌和结构进行表征。结果显示,H_3PW_(12)O_(40)存在于夹层膜的上层与下层,且其Keggin结构未遭到破坏。与H_3PW_(12)O_(40)粉末和H_3PW_(12)O_(40)/PMMA复合纳米纤维膜相比,夹层膜对甲基橙(MO)具有更高的光催化活性。夹层纳米纤维膜易于回收并能重复使用,循环使用3次后光催化活性无明显下降,主要归咎于H_3PW_(12)O_(40)稳定地负载于纳米纤维膜中。因此,H_3PW_(12)O_(40)/PMMA/PA6夹层复合纳米纤维膜在水污染治理领域具有潜在的实际应用价值。     

Hydrothermal synthesis of sheaf-like CuO via ionic liquids

Sheaf-like CuO consisting of nanoplatelets were synthesized by a hydrothermal method at 100 °C from Cu(NO₃)₂·3H₂O and NaOH in the presence of an ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF₄). The XRD indicated the high crystal quality of CuO with monoclinic crystal structure. FESEM and TEM images showed the nanoplatelets with lengths of 4-5 μm, thickness of 65-80 nm and end angle of 60°. FTIR spectra and TG/DSC curves confirmed the adsorption of [BMIM]BF₄ on the surface of CuO. The morphology of CuO could be controlled by the feeding manner of [BMIM]BF₄. It was demonstrated that [BMIM]BF₄ served as a cosolvent and modifiers in the reaction system. Further, the possible growth mechanism of the sheaf-like CuO was proposed.     

A Green Chemical Synthesis and Characterization of Mn3O4 nanoparticles

Mn₃O₄ nanoparticles were synthesized via an ionic liquid (IL) assisted process at room temperature, which is rather difficult to achieve by other techniques. The synthesized product was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetry (TG), and vibrating sample magnetometry (VSM). The prepared material showed a high purity, while crystallite size and particle size agree well with each other, 17±2 and 19±3?nm, respectively, revealing nearly single crystalline character of nanoparticles. The product contains 4?wt% of adsorbed water and ionic liquid. This method provides a facile, one-step, and low-cost route for the synthesis of nanostructures of metal oxides. In addition, [BMIM]BF₄ could be collected and reused for subsequent reactions.     

Syntheses and ultra-deep desulfurization performance of sandwich-type polyoxometalate-based TiO<Subscript>2</Subscript> nanofibres

The sandwich-type polyoxometalate-based TiO₂ nanofibres were prepared successfully by electrospinning combining with chemical reaction and employed in ultra-deep desulfurization. OTA–CoVW–TiO₂ nanofibres (OTA?=?CH₃(CH₂)₁₇(CH₃)₃N, CoVW?=?[Co₄(H₂O)₂(VW₉O₃₄)₂]^10?) confirmed the excellent desulfurization performance in extraction catalytic oxidative desulfurization system (ECODS). At 323 K, the 500 ppm DBT (dibenzothiophene) model oil was entirely removed within 20 min using 0.010 g 45 wt% OTA–CoVW–TiO₂ nanofibres as catalyst when O/S molar ratio was 4:1 and the dosage of model oil was 5 mL. The catalysts could be recycled and reused at least five times without remarkable decrease in catalytic activity. The desulfurization efficiencies for different substrates were shown as following order: DBT?>?4,6-DMDBT (4,6-dimethyl-dibenzothiophene)?>?BT (benzothiophene). Moreover, the possible mechanism was also elucidated.     

Double layer micellar stabilization of gold nanocrystals by greener ionic liquid 1-butyl-3-methylimidazolium lauryl sulfate

We report the first synthesis of anisotropic gold nanocrystals (AuNC) prepared by a seeding approach using the greener ionic liquid, 1-butyl-3-methylimidazolium lauryl sulfate, [BMIM] [C₁₂H₂₅OSO₃]. Crystal growth was successfully achieved by successive addition of growth solution containing HAuCl₄ and ascorbic acid to 2.5-nm Au seeds. These nanocrystals were stabilized by the ionic liquid via a two layer micellar formation. SEM and TEM results showed Au nanocrystals with particle sizes ranging from 20 to 50 nm. Selected-area electron diffraction (SAED) and PXRD pattern gave indices that correspond to Au nanocrystals. Direct addition of ionic liquid to Au seeds in 3:1 volume ratio afforded the formation of Au nanoparticles. TEM image and UV-vis data revealed the formation of 20-50 nm Au nanocrystals. These results show that the greener ionic liquid, [BMIM] [C₁₂H₂₅OSO₃], is a suitable reaction medium for the direct synthesis of larger Au nanoparticles from Au seeds.     

FeCl3低温共熔Cl深度萃取模拟油脱硫性能的研究

用 N-甲基咪唑和氯代正辛烷为原料,首先合成出中间体[Omim]Cl,然后与几种典型的金属氯化物按不同的物质的量比合成出了一系列的离子液体,采用红外光谱对其进行表征,并考察了离子液体对正辛烷中二苯并噻吩的萃取脱除效果。对几种不同的离子液体的脱硫性能进行了初步比较,并针对[Omim]Cl·2FeCl3离子液体详尽考察了剂油体积比、萃取时间、萃取温度、硫化物的种类、重复利用次数等因素对脱硫率的影响。结果表明,萃取温度为25℃,萃取时间为20 min,剂油体积比为1∶20时,[Omim]Cl·2FeCl3对 DBT 的脱除率高达99.20%,并且对4种不同含硫组分的脱除能力：DBT>BT>T>3-MT。且离子液体再重复使用5次后,对 DBT 的脱除率还能够达到89.56%,离子液体经回收之后,对 DBT 的脱除率没有明显的下降,表明再生效果良好。实验数据对咪唑离子液体的萃取脱硫性能研究和反应条件的优选提供了重要信息。     

Ag3PO4/BigFe4O9复合催化剂的制备及其光催化性能

利用水热法成功地制备得到具有高效光催化活性的Ag3PO4/Bi2Fe4O9复合型光催化剂.使用X-射线多晶粉末衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对样品进行表征,并以罗丹明B为目标降解物对其光催化性能进行研究.结果表明:样品是由纳米Ag3 PO4颗粒负载在片状四边形的Bi2Fe4O9表面组成的,当Ag3PO4的负载量为4wt％时,复合材料的光催化效果最好,在可见光(波长＞420nm)照射下,1.5h内对100mL浓度为10-5mol.L-1罗丹明B溶液的脱色率可达98.7％.     

Magnetic recyclable Ag catalysts with a hierarchical nanostructure

This study reports the fabrication of a novel hierarchically structured nanocatalyst system possessing a well-defined nickel silicate (NS) protected Fe(3)O(4) core and a layer of uniform Ag nanoparticles on the NS shell by using a multi-step approach. The multifunctional microparticles show high performance in the reduction of 4-nitrophenol and the rate of the catalytic reaction can be controlled by changing the concentration of nanocatalysts. In particular, there was no visible decrease in the catalytic activity of the reused catalysts even after being recycled five times. Thus the hierarchically structured Fe(3)O(4)@NS particles are very suitable as a catalyst support for catalyst separation and redispersion.