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分别以Y沸石、活性碳和二氧化硅-壳聚糖(SiO2-CS)为载体、利用浸渍法制备了一系列负载型七水三氯化铈-碘化钠(CeCl3·7H2O-NaI)催化剂,考察了它们在叔丁基苯基醚的脱保护反应中的催化性能。 结果表明,SiO2-CS为载体的催化剂呈现出良好的催化性能和较高的稳定性。 另外,在中性条件下,SiO2-CS负载CeCl3·7H2O-NaI催化剂在叔丁基醚及1,3-二硫缩醛脱保护反应中呈现出较高的催化活性,从而避免使用强酸和强碱。 相似文献
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采用等体积浸渍法制备了不同负载量的固体酸催化剂SO42-/SnO2/SBA-15,利用X射线粉末衍射、N2吸附-脱附和透射电镜等手段对样品进行了表征,并考察了催化剂对4-叔丁基环己酮与乙二醇缩合反应的催化性能.结果表明,SO42-/SnO2催化剂负载于SBA-15后其催化性能明显改善.研究了SO42-/20%SnO2/SBA-15催化剂上部分酮类化合物与乙二醇及1,2-丙二醇的缩合反应,并考察了反应时间和催化剂用量等因素对反应性能的影响.在适宜的温和条件下,一些环酮类底物如环己酮、4-甲基环己酮和4-叔丁基环己酮等均可反应得到相应的缩醛化产物,且催化剂至少可循环使用4次. 相似文献
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Al-SBA-15介孔分子筛的合成、表征及其在苯酚叔丁基化反应中的催化性能 总被引:14,自引:0,他引:14
通过嫁接的方法合成了Al-SBA-15介孔分子筛,用X射线衍射、透射电子显微镜、低温N2吸附和NH3程序升温脱附等方法进行了表征,并研究了其在苯酚叔丁基化反应中的催化性能. 结果表明, Al-SBA-15保持了母体SBA-15高度有序的六方介孔结构,具有较强的酸性,且在苯酚叔丁基化反应中表现出比Al-MCM-41更好的催化活性和2,4-二叔丁基苯酚选择性. 相似文献
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研究了脱铝HY沸石(n(Si)/n(Al)=3.8)上萘(naph)的选择性叔丁基化反应。结果表明,八面沸石对该反应过程有较好的择形催化作用,两种异构化产物(2,6-二叔丁基萘和2,7-二叔丁基萘)之间存在着热力学平衡,即两种异构化产物可在酸性中心上相互转化,在以叔丁醇为烷基化试剂,WHSV=2h^-1,n(t-BuOH)/n(naph)=3,反应温度为120℃的反应条件下,萘的转化率可达98.43%,β-位选择性可高达100%,二叔丁基萘收率可达74.34%,2,6-二叔丁基萘/2,7-二叔丁基萘/2,7-叔丁基萘质量比为6.24。 相似文献
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以对叔丁基苯酚为原料,经环化缩合、脱叔丁基、酚羟基醚化、甲酰化和氧化反应制得5-羧基-25,26,27,28-四正丙基杯[4]芳烃(5);5与O-苄基-N-苄氧羰基丝氨酸反应制得5-(O-丝氨酸)-25,26,27,28-四正丙基杯[4]甲酸酯(7),其结构经~1H NMR,~(13)C NMR和MS(ESI)表征。研究了溶剂和水的用量对7催化性能的影响。结果表明:水为溶剂,其用量为10 eq.时,收率和非对映选择性分别为95%和3∶97 dr;当水的用量为30 eq.时,收率和非对映选择性分别为93%和98∶2 dr。 相似文献
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Yilmaz N Mizukami M Kurihara K 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):6070-6075
The adsorption of phenol, an aromatic compound with a hydrogen-bonding group, onto a silica surface in cyclohexane was investigated by colloidal probe atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and adsorption isotherm measurements. ATR-FTIR measurements on the silica surface indicated the formation of surface macroclusters of phenol through hydrogen bonding. The ATR-FTIR spectra were also measured on the H-terminated silicon surface to observe the effect of the silanol groups on the phenol adsorption. The comparison of the ATR-FTIR spectra for both the silicon oxide and H-terminated silicon surfaces proved that the silanol groups are necessary for the formation of phenol clusters on the surface. The surface force measurement using colloidal probe AFM showed a long-range attraction between the two silica surfaces in phenol-cyclohexane mixtures. This long-range attraction resulted from the contact of the adsorbed phenol layers for the phenol concentrations below 0.6 mol %, at which no significant phenol clusters formed in the bulk solution. The attraction started to decrease at 0.6 mol % phenol due to the exchange of the phenol molecules between the clusters in the bulk phase and on the surface. The surface density of phenol in the adsorbed layer was calculated on the basis of the long-range attraction and found to be much smaller than the liquid phenol density. The plausible structure of the adsorbed phenol layer was drawn by referring to the crystal structure of the bulk phenol and orientation of the phenol molecules on the surface, estimated by the dichroic analysis of ATR-FTIR spectroscopy. The investigation of the phenol adsorption on the silica surface in a nonpolar solvent using this novel approach demonstrated the effect of the aromatic ring on the surface packing density. 相似文献
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Guang-Ming Zeng Ke Xu Jin-Hui Huang Xue Li Yao-Yao Fang Yun-Huan Qu 《Journal of membrane science》2008,310(1-2):149-160
The micellar enhanced ultrafiltration (MEUF) of phenol in synthetic wastewater using two polysulfone spiral membranes of 6- and 10-kDa molecule weight cut-off (MWCO) and cetylpyridinium chloride (CPC) as cationic surfactant was studied. The effects on the permeate flux, permeate and retentate concentrations of phenol and CPC of various factors in the practical application of MEUF were studied, including surfactant and phenol concentrations, retentate flux, operating pressure, temperature and electrolyte. It was found that these two membranes could adsorb free phenol so the concentration of permeate phenol was lower than that of free phenol. The retentate phenol concentration kept increasing, then decreased slightly with the increase of the feed CPC concentration. Retentate flux and temperature had great effect on the performance of MEUF, and operating pressure did not. The addition of sodium carbonate (Na2CO3) could increase the retentate phenol concentration and decrease the permeate concentrations of phenol and CPC significantly. 相似文献
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Dalia Ovadyahu S. Yariv I. Lapides Y. Deutsch 《Journal of Thermal Analysis and Calorimetry》1998,51(2):415-430
The mechanochemical adsorption of phenol by laponite, saponite, montmorillonite, beidellite and vermiculite was studied by IR and X-ray spectroscopy. Mixtures containing phenol and clay in the ratio of 6:10 were manually ground by a mortar and pestle for 1,3,5 and 10 min and the ground mixtures were investigated. Depending on the basicity of the clay mineral and the time of grinding, two different associations between interlay er cations, water and phenol were identified. In these associations phenol can act either as a proton acceptor or donor (Configurations I and II, respectively). The phenol is more acidic than water and in most cases phenol acts as a proton donor. With montmorillonite and beidellite phenol acts as a proton acceptor. In this association the aromatic ring forms π bonds with atoms of the oxygen planes of the tetrahedral sheets which donate electrons to the anti-bonding π orbitals of the phenol. 相似文献
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用循环伏安法研究了Ti/PbO2电极在苯酚硫酸溶液中的电催化作用. 结果表明, 在硫酸溶液中, Ti/PbO2阳极对苯酚具有电催化氧化作用. 如果苯酚浓度较低, 产生的吸附态羟基自由基可以将苯酚氧化, 直至完全矿化. 当苯酚浓度较高或产生的羟基自由基量相对较小时, 苯酚或中间产物可吸附在电极表面, 降低电极的真实表面积, 减少电极的活性点, 阻止反应物接近电极表面, 抑制苯酚的进一步氧化. 随着电解时间的延长, 这些吸附物由于逐渐被氧化, 电极活性恢复. 相似文献
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Martin Mkandawire Jochen Förster Dirk Fiedler Horst Böttcher Wolfgang Pompe 《International journal of environmental analytical chemistry》2013,93(7):529-541
A quick fingerprint spectrophotometric procedure based on the absorbance in the ultraviolet spectrum region was developed to verify biodegradation of phenol in flowing contaminated water. The procedure was employed to test the functional feasibility of a biocers-packed bioreactor to filter phenol on a bench-scale fluidic dynamic system, which should simulate a macroscopic microorganism-based remediation system. The biocers contained Rhodococcus sp. P1, a phenol degrading bacteria. An influent with initial phenol concentration of 500 mg L?1 was fed into the bioreactor at different flow rates, and the effluent was continuously monitored for residual phenol concentration by coupling the fluid dynamic system to a UV-vis spectrophotometer. Within 3 days, the effluent from bioreactor reached a minimum residual concentration of phenol of <40 mg L?1. Therefore, the aim of the current paper is to report results of the procedure for on-line spectrophotometric detection of phenol, and the feasibility of a biocers-packed bioreactor for degradation of phenol. 相似文献
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S. A. Zabelkin A. N. Grachev G. M. Bikbulatova A. E. Yakovleva A. A. Makarov V. N. Bashkirov 《Polymer Science Series D》2018,11(2):131-134
A method of preparation of a phenol–formaldehyde resin by replacing phenol with liquid products of the fast pyrolysis of wood is described. Strength tests reveal that substituting a pyrolysis liquid for 60% of phenol in the phenol–formaldehyde resin allows strength to be increased by 6% relative to the control sample. 相似文献
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The effect of lead (Pb) on the sorption of phenol onto montmorillonite-based sorbents was studied using a batch equilibration method when phenol and Pb were sorbed simultaneously and either Pb or phenol was previously sorbed. The sorbents were Na(+)-, Ca(2+)-, hexadecyl trimethylammonium (HDTMA)-Na(+)-, and HDTMA-Ca(2+)-montmorillonites. Pb diminished the sorption of phenol largely onto Na(+)- or Ca(2+)-montmorillonites, while phenol had little effect on the sorption of Pb onto all sorbents. Pb had no effect on the sorption of phenol onto HDTMA-Na(+)- or HDTMA-Ca(2+)-montmorillonites either. The sorption capacity of phenol followed the order HDTMA-Na(+)- > HDTMA-Ca(2+)- > Na(+)- > Ca(2+)-montmorillonites. The pseudo-second-order equation described the kinetics of phenol sorption well. Sorption isotherms of phenol followed the Freundlich equation. Phenol sorption on HDTMA-Na(+)- and HDTMA-Ca(2+)-montmorillonites was linear, while that on Na(+)- and Ca(2+)-montmorillonites was nonlinear. 相似文献
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电化学氧化法去除苯酚研究 总被引:9,自引:0,他引:9
利用氯碱厂报废的DSA电极电解苯酚,结果显示:此电极对一定浓度的苯酚溶液有较好的去除效果.按影响电解效果各主要因素进行筛选,最佳实验条件为:电流密度30mA/cm2,pH10,支持电解质浓度10mg/L,苯酚浓度10mg/L.电解2h后,CODcr的去除率为66.7%,吸光度去除率为90%. 相似文献