KF/膨润土催化剂的制备及其在活泼亚甲基烷基化中的应用

钙基膨润土钠化后，负载一定量KF，焙烧制得KF/膨润土催化剂。以溴代正丁烷与乙酰乙酸乙酯的烷基化反应为探针反应，考察了催化剂制备条件及反应工艺条件对收率的影响。结果表明，在溴代正丁烷0.02 mol、乙酰乙酸乙酯0.01 mol、催化剂用量0.4 g和85 ℃条件下反应4.0 h，2-正丁基乙酰乙酸乙酯收率达38.6%，体现出催化剂对活泼亚甲基的烷基化反应具有良好活性。     

Effect of halogen anion on hexane aromatization activity of Pt/KL catalysts

Potassium salts were added to the catalyst prepared by ion exchange of KL with [Pt(NH3)₄]Cl₂ and the effect of their counter anion on the activity and selectivity for hexane aromatization was studied. The catalyst to which KF was added showed the highest activity and selectivity for benzene formation; methylcyclopentane and hydroisomerization products were negligible. Although the catalyst with KCl added also exhibited excellent performance, the catalysts with KBr or KI added gave rise to low hexane conversion and benzene yield. Infra-red spectra of adsorbed CO revealed that the presence of the low frequency C-O stretching band is closely related to catalytic performance of the Pt/KL series catalysts. The electron-rich Pt site formed through the interaction with KF or KCl may be responsible for the high activity and selectivity for hexane aromatization.     

KF/γ-Al_2O_3制备条件对催化合成八乙酸蔗糖酯的影响

用KF/γ-Al2O3为催化剂合成八乙酸蔗糖酯,研究了KF负载量、焙烧温度、焙烧时间对催化剂活性的影响,得到了较佳制备条件为:KF负载量25%、焙烧温度600℃、焙烧时间6 h。八乙酸蔗糖酯产率最高可达86.2%。产品经熔点和IR测试,证实了自制产品与美国产品的纯度基本一致。     

纳米固体碱催化剂KF/CaO-MgO制备生物柴油

采用共沉淀法制备复合物CaO-MgO,再以等体积浸渍法负载KF,制备了负载型固体碱催化剂KF/CaO-MgO,并将其用于催化菜籽油与甲醇酯交换反应制备生物柴油。考察了催化剂制备条件对酯交换反应的影响,并用扫描电镜、透射电镜和X射线衍射仪等手段对催化剂进行表征。结果表明,在m(CaO)∶m(MgO)=9∶1、KF负载量为载体质量的25%和600 ℃焙烧3 h制备的催化剂具有较好的催化活性,酯化率达95%以上。催化剂具有多孔结构,孔径在100 nm左右,催化剂粒径（30~50） nm,是负载型纳米固体碱催化剂。     

KF848和FC-14在高压加氢裂化装置的湿法硫化过程

介绍了以KF848为主的精制催化剂与裂化催化剂FC-14和FF-36在辽阳石化100万t/a加氢裂化装置开工过程中的湿法硫化过程.在湿法硫化过程中,通过升温过程的温升大小的变化,可以看出KF848等精制催化剂表现出较高的活性,FC-14和FF-36催化剂活性比较温和,为正常生产提供了重要的参数依据.同时在各催化剂床层温...     

Preparation of Mesoporous Nanosized KF/CaO–MgO Catalyst and its Application for Biodiesel Production by Transesterification

A mesoporous nanosized KF/CaO–MgO catalyst was prepared by coprecipitation method, and was characterized by transmission electron microscopy, X-ray diffraction, nitrogen adsorption and laser confocal Raman microspectroscopy. The catalyst possessed a unique mesoporous structure with pore size of ca. 34 nm and the average particle size of ca. 35 nm. In comparison with CaO and KF/CaO catalyst, the as-prepared catalyst exhibited higher catalytic activity, higher resistance to saponification, and better acidoresistance (10 mg KOH/g oil). The factors affecting on transesterification were also investigated, and a desired biodiesel yield over 95% was obtained under an optimal preparation conditions.     

Synthesis of diethyl carbonate from dimethyl carbonate and ethanol using KF/Al2O3 as an efficient solid base catalyst

Diethyl carbonate, an efficient oxygen-containing fuel additive was synthesized from dimethyl carbonate and ethanol using KF/Al₂O₃. The catalysts prepared with different KF loading were characterized using X-ray diffraction, BET surface area and basicity measurement analyses. The effects of different reaction parameters such as temperature, reactant ratio and amount of catalyst were optimized. Among the different alkali halides, 20 wt.% KF supported on alumina exhibited 61.6% diethyl carbonate selectivity with 96% dimethyl carbonate conversion under optimum reaction conditions. The plausible reaction mechanism is proposed based on the results obtained. The possibility of recycling the catalyst was ensured without appreciable loss in activity for four cycles.     

KF/C催化甘油酯交换合成碳酸甘油酯

以三嵌段共聚物(EO-PO-EO)F127为结构导向剂,甲阶酚醛树脂为碳源,KF·2H₂O为无机前驱体,用溶剂诱导挥发自组装的方法合成KF/C复合材料。采用XRD、BET和XPS等手段对合成的材料进行结构表征,并考察KF/C在甘油与碳酸二甲酯酯交换合成碳酸甘油酯反应中的性能,结果表明,在甘油加入量为0.184 6 g、碳酸二甲酯加入量为0.900 7 g、溶剂N,N-二甲基乙酰胺为5.426 g、催化剂KF/C加入量为0.1 g、反应温度100 ℃、反应时间2 h和搅拌速率600 r·min^-1条件下,甘油转化率达98.5%,碳酸甘油酯选择性达99.8%,催化剂具有较好的循环使用性能。     

Application of KF/MgO as a heterogeneous catalyst in the production of biodiesel from rapeseed oil

Biodiesel was synthesized from rapeseed oil by transesterification over Magnesium oxide loaded with KF. The catalytic activity strongly depends on the loading amount of KF and calcined temperature. We found that the reaction reached a 79.37% yield when the loading amount was at 35 wt% and calcined at 500 °C. The simply dried 30% KF/MgO at 80 °C was found to give equally good results from the catalyst calcined at 500 °C, avoiding the usual activation at high temperature. The catalysts were characterized by the Hammett indicator method, BET, TG/DTG, XRD, NMR, EDS, and FT-IR. According to the instrumental analysis, the activity in the transesterification probably belonged to coordinately unsaturated F⁻ and liberation of hydroxide during preparation. The effects of methanol/oil ratio and catalyst amounts on the conversion were also studied in this paper.     

制备生物柴油的负载型催化剂KF/CaO/陶土的研究

以共混/浸渍法制备复合负载型固体碱催化剂KF/CaO/陶土,考察了催化剂制备条件对催化活性的影响,以SEM、TEM、BET等手段对催化剂进行了表征。结果表明：焙烧温度为600 ℃,焙烧时间为4 h,陶土与CaO质量比为3∶7,浸渍剂KF占陶土与CaO总质量的20%时,催化乌桕籽油制备生物柴油的收率可达96%以上。催化剂结构表征显示,该催化剂呈多孔网状结构,粒径主要分布在30～100 nm,平均孔径分布为43 nm,表面积为113.9 m2/g。     

固体碱催化酯交换法制备生物柴油的研究

用浸渍法制备了KF/Al2O3负载催化剂,并将负载催化剂用于菜籽油与甲醇酯交换合成生物柴油的研究。考查了不同负载量、不同煅烧温度对催化剂活性的影响,肯定了KF/Al2O3催化剂存在产生强碱位,并利用GC-MS对生物柴油进行了检测。结果表明,生物柴油的主要成分为油酸甲酯,其含量达到50%以上。     

KF催化无溶剂合成香豆素-3-甲酸乙酯

以水杨醛和丙二酸二乙酯为原料,分别选用4种无机盐代替六氢吡啶作催化剂,催化合成香豆素-3-甲酸乙酯.结果表明,KF· 2H2O与无水K2CO3具有明显的催化活性.通过设计正交试验考察了反应物摩尔比、催化剂KF·2H2O用量、反应时间等因素对反应产率的影响,获得优化工艺条件为:水杨醛用量5.0 g(4.2 mL,0.041 mol),水杨醛与丙二酸二乙酯摩尔比1∶1.2,KF·2H2O用量0.46g,无溶剂条件下加热蒸馏反应约45 min,平均产率可选89.71％.     

纳米催化剂KF/γ-Al_2O_3的制备及催化乌桕籽油制备生物柴油

以γ-Al2O3为载体负载KF,制备纳米KF/γ-Al2O3酯交换催化剂,用于催化乌桕籽油制备生物柴油,研究了不同制备条件下纳米催化剂KF/γ-Al2O3的催化性能。结果表明,当KF.2H2O的用量为18 g,共混反应温度为65℃,煅烧温度为300℃,煅烧时间为2.5 h时,酯化率可达90%以上。TG-DSC热分析表明,催化剂具有较好的热稳定性,温度高于400℃时,会产生晶相转移现象使催化剂活性点有所减少;通过SEM、TEM表征,催化剂表面呈多孔状,颗粒大小在50~100 nm,是一类纳米固体碱催化剂。     

负载型固体碱催化合成假性紫罗兰酮的研究

制备了三种不同的负载型固体碱催化剂用于假性紫罗兰酮的合成。通过对假性紫罗兰酮收率的考察，得到了催化活性较好的负载型固体碱KF/Al₂O₃；通过正交实验探讨了催化剂的干燥温度、催化剂的负载量、反应物柠檬醛和丙酮的配比对假性紫罗兰酮收率的影响。     

KF/K2CO3/γ-Al2O3催化合成肉桂酸

以苯甲醛和丙二酸为原料,KF/K2CO3/γ-Al2O3为催化剂,经Knoevenagel反应,在无溶剂条件下催化合成了肉桂酸。产品用IR、1HNMR及元素分析进行表征。考察了催化剂用量、苯甲醛与丙二酸摩尔比和反应时间对肉桂酸收率的影响。结果表明:KF/K2CO3/γ-Al2O3具有良好的催化活性,较佳工艺条件为:苯甲醛10.2 mL(10.6 g,0.1 mol),n(苯甲醛)∶n(丙二酸)=1∶1.15,催化剂KF/K2CO3/γ-Al2O3用量2.5 g(含KF4.68 mmol),反应60 min,肉桂酸的平均收率达到92%以上。     

KF/K_2CO_3/γ-Al_2O_3催化合成香豆素-3-羧酸

以水杨醛和丙二酸二乙酯为原料,KF/K_2CO_3/γ-Al_2O_3为催化剂,催化合成香豆素-3-羧酸乙酯,再经皂化、酸解环合合成香豆素-3-羧酸.考察了催化剂用量、水杨醛与丙二酸二乙酯摩尔比、反应时间等因素对香豆素-3-羧酸收率的影响.结果表明,KF/K_2CO_3/γ-Al_2O_3具有良好的催化活性,较佳工艺条件为:水杨醛4.88 g(0.04 mol),n(水杨醛),n(丙二酸二乙酯)=1:1.25,KF/K_2CO_3/γ-Al_2O_3 2.0 g(KF 3.74 mmol),无水乙醇20 mL,反应1.5 h,香豆素-3-羧酸的平均收率达到92%以上.     

用于生物柴油制备的KF/Al2O3固体碱催化剂的研究

采用浸渍法制备了KF/Al₂O₃固体碱催化剂，并将其应用于大豆油与甲醇酯交换制备生物柴油的反应。通过酯交换反应的转化率对催化剂制备工艺进行了优化，得出最佳制备条件：KF理论负载质量分数为Al₂O₃的45%，浸渍时间6 h，焙烧温度500 ℃，优化条件下制备的催化剂在大豆油与甲醇物质的量比为12∶1、催化剂用量为油质量的2%、反应时间3 h和反应温度(60～65) ℃条件下,酯交换转化率可达97.15%。     

Preparation of KF/CaO nanocatalyst and its application in biodiesel production from Chinese tallow seed oil

KF/CaO nanocatalyst was prepared by using impregnation method and used to convert Chinese tallow seed oil to biodiesel. The effects of different preparation conditions on biodiesel yield were investigated and the structure of the catalyst was characterized. Transmission electron microscopy (TEM) photograph showed that the catalyst had porous structure with the particle size of 30-100 nm. Brunauer-Emmet-Teller (BET) analysis indicated that the catalyst specific surface area was 109 m² g⁻¹ and average pore size was 97 nm. X-ray diffractometer (XRD) analysis demonstrated that the new crystal KCaF₃ was formed in catalyst, which enhanced catalytic ability. Under the optimal conditions, the biodiesel yield was 96.8% in the presence of as-prepared KF/CaO catalyst, showing potential applications of catalyst in biodiesel industry.     

KF/MgO催化酯交换法合成碳酸二月桂酯

The catalytic properties of KF/MgO for the synthesis of didodecyl carbonate (DDC) by transesterification from dimethyl carbonate (DMC) and dodecanol were studied. The effects of loading amount of KF and calcining temperature were systemically investigated. The phase structure was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Interaction between KF and the carrier MgO occurred in the process of calcination, and a new phase K2MgF4 formed when calcining temperature was 673 K or above. FTIR results showed that K2CO3 was observed when catalysts calcined in air. When calcining tem-perature was 873 K and the loading mass amount of KF was 30%, the KF/MgO catalyst exhibited the optimal catalytic properties and the yield of DDC was maximized to 80%. The excellent catalytic properties of KF/MgO was ascribed to the formation of K2MgF4+K2CO3 during the calcination in air.     

Disproportionation of trimethoxysilane over an alumina-supported KF catalyst

An alumina-supported KF catalyst shows a high activity for the disproportionation of trimethoxysilane to give silane and tetramethoxysilane. Using KF (2-15 mmol g^-1)/Al₂O₃, a 76% trimethoxysilane conversion was obtained for the reaction at 393 K in a fixed-bed flow reactor. This revised version was published online in July 2006 with corrections to the Cover Date.