共查询到17条相似文献,搜索用时 109 毫秒
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采用传统浸渍法制备出两种负载镍金属有序介孔氧化铝,并采用BET法比表面积测定、X射线衍射
(XRD)、程序升温还原(TPR)、X射线光电子能谱分析(XPS)、透射电镜(TEM)、电感耦合等离子体发射光谱仪(ICP-OES)等多种测试技术对合成的催化剂进行表征。通过一氧化碳甲烷化反应测定其催化活性并与负载镍金属普通氧化铝进行对比。实验结果表明,镍在两种有序介孔氧化铝上主要呈两种形态,即氧化镍和偏铝酸镍。合成的介孔氧化铝比普通氧化铝镍负载量大且分散性好,这主要归结于其具有的高比表面积(300~500 m2/g)及窄孔径分布(4~
10 nm)的稳定有序结构。催化结果表明:由于具有较高的镍负载量及较好的镍金属分散性能,因而负载镍金属有序介孔氧化铝比普通氧化铝具有较好的催化活性。 相似文献
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《高校化学工程学报》2016,(1)
采用溶胶-凝胶法,以离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF_6)为模板、异丙醇铝为铝源合成介孔氧化铝,重点考察了离子液体用量和煅烧温度对氧化铝介孔结构的影响,用X射线衍射仪(XRD)、场发射透射电子显微镜(TEM)、氮气物理吸脱附仪、傅里叶红外分析仪(FT-IR)等手段对合成样品进行了表征。研究结果表明,离子液体对氧化铝的介孔构建起到了模板调控的作用,适量的离子液体有助于有序介孔的构建;煅烧温度影响孔道参数,温度过高导致孔道坍塌会造成比表面积、孔径、孔容的减小。当离子液体与异丙醇铝的摩尔比为0.018、煅烧温度为500℃下可获得相对有序的介孔γ-Al_2O_3,其比表面积最大为447 m~2×g~(-1),最大孔容1.17 cm~3×g~(-1),平均孔径7.6 nm。此外还对离子液体合成介孔氧化铝的微观机理进行了探讨。 相似文献
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介孔氧化铝的合成及应用 总被引:1,自引:0,他引:1
通过对介孔氧化硅合成工艺的优化与修正可以用来制备介孔氧化铝分子筛。在合成介孔分子筛的前驱物中掺杂其他金属元素而将其引入骨架或将活性组分负载到介孔分子筛的基体上,可以实现对介孔分子筛表面进行表面修饰与改性,以调变分子筛表面的酸催化性能。本文综述了介孔氧化铝合成、改性研究的历史与现状,及在酸催化过程中的应用。 相似文献
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Rong Kou Qingyuan Hu Donghai Wang Vijay T. John Zhenzhong Yang Yunfeng Lu 《Journal of Porous Materials》2009,16(3):315-319
One-dimensional mesoporous polymer/carbon nanofilaments with controlled mesostructures have been prepared by an infiltration
process of phenolic oligomers/surfactant into anodized alumina membranes followed by carbonization. Transmission electron
microscopy (TEM), nitrogen sorption and X-ray diffraction (XRD) investigations show that as-prepared polymer nanofilaments
possess ordered mesoporous structure tunable from circular hexagonal to cubic and concentric lamellar mesostructures. After
carbonization, carbon nanofilaments with corresponding circular hexagonal, cubic and concentric lamellar mesoporous structure
are obtained. 相似文献
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CO甲烷化在煤制天然气技术中起着重要作用,Ni基催化剂作为目前研究最多的甲烷化催化剂,仍存在低温活性差、高温易烧结和易积炭等问题。针对这些问题,采用改进的溶剂蒸发诱导自组装方法,设计制备了不同含量Nd物种修饰的Ni-Nd-Al三元有序介孔甲烷化催化剂。采用N2-物理吸附、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等分析方法对反应前后催化剂的结构和形貌进行了表征,并考察其CO甲烷化反应催化性能。结果表明,制备出的Ni-Nd-Al甲烷化催化剂均具有有序介孔结构,Ni和Nd物种均匀分布在孔道内。适量Nd物种的加入有助于减小Ni颗粒的尺寸,提高其分散度和对H2的吸附能力,进而提升催化剂的活性。有序介孔结构的限域效应有助于提高催化剂抗烧结和抗积炭能力。 相似文献
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Morphologically controlled synthesis of mesoporous alumina 总被引:1,自引:0,他引:1
Qian Liu Aiqin Wang Xiaodong Wang Tao Zhang 《Microporous and mesoporous materials》2007,100(1-3):35-44
The morphologically controlled synthesis of mesoporous alumina using Al(NO3)3/NH3/urea/surfactant reaction system is demonstrated. Both the mesostructures and morphologies of the resulting alumina can be effectively controlled via adjusting the synthesis parameters, including reactant compositions, surfactant kinds and hydrothermal conditions. With the aid of surfactants, mesoporous alumina with spheres, rods, fibers and three-dimensional dumbbell, flower-like hierarchical superstructures on the microscopic scale has been obtained. Through characterization by N2 physisorption, X-ray diffraction, electron microscopy and thermogravimetry analysis, the effects of synthesis conditions on structures and shapes of products are explained and the possible formation mechanism of the controlled morphologies is also proposed. 相似文献
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Mesoporous alumina has been synthesised by the solution combustion synthesis method. While often the synthesis of mesoporous
materials with a relatively narrow pore distribution requires the use of a template, this technique allows a simple and rapid
synthesis of pure alumina without the use of any templating agent: by regulating the synthesis conditions is possible to obtain
from relatively low surface area α-alumina to high surface mesoporous γ-alumina. The porosity of the latter was assessed chiefly
by density functional method and was found to be in the range 2.8–3.5 nm. Low angle X-ray diffraction experiments demonstrated
a partial ordering of the structure, with a periodicity in the range 5.5–6.9 nm. The addition of lanthanum to the alumina
was tested and found to confer a good temperature resistance to the alumina, without modifying the mesoporous structure. After
a prolonged heat treatment at 900 °C the mesoporosity of lanthanum-modified samples was retained, even if the pores size increased
and the specific surface area decreased. 相似文献