双功能负载型镍的制备及其催化的芳烃和芳醚的加氢转化

发布时间：2018-05-19 23:16

本文选题：羰基镍 + 芳烃　；参考：《中国矿业大学》2016年硕士论文

【摘要】：芳烃与芳醚的加氢转化是当今重质碳资源利用的重点课题,开发高活性的负载金属催化剂是芳烃和芳醚转化的关键技术,镍是芳香族化合物加氢转化催化剂的主要组分;羰基镍在较低温度下原为分解直接生成分散度极好的镍颗粒,但羰基镍挥发温度较低,故极难在载体上稳定分解。本课题以羰基镍为镍的前驱体,以5A分子筛(Z5A)为载体,乙醚为溶剂,采用原位分解的方法在高压釜中制备Z5A负载的镍催化剂Ni/Z5A。此催化剂经一系列表征,即透射电镜(TEM)配合电子能谱(EDS)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)、NH3程序升温脱附(NH3-TPD)、光电子能谱(XPS)、傅里叶变换红外光谱仪(FTIR)等分析,结果表明金属负载量较低,很好的分散在分子筛上甚至以非晶态的形式负载,金属镍与载体具有强相互作用。通过考察不同温度下9-苯蒽和苯基苄基醚在Ni/Z5A催化剂上的加氢转化,发现在200oC时Ni/Z5A对9-苯蒽和苯基苄基醚有很好的加氢效果,主要产物分别为9-苯蒽的全氢产物和甲基环己烷。Ni/Z5A具有双功能特性:活化H2形成双原子活性氢;二是将H2异裂为游离于Ni/Z5A的H+和吸附在Ni/Z5A上的H-,基于此机理,在200 oC下以1-萘酚和二苄醚(OBMDB)为底物研究催化加氢产物及其变化规律,1-萘酚的主要产物为四氢萘和十氢萘,OBMDB的产物主要为甲基环己烷和甲苯,采用Ni/Z5A的机理得到合理解释。Ni/Z5A可以重复使用多次,转化率降低的原因是长时间反应引起负载镍颗粒的团聚。为探究催化剂的工业应用价值,以Ni/Z5A分别催化低温煤焦油(LTCT)、高温煤焦油(HTCT)以及沥青挥发分(PV)的加氢转化,通过气相色谱/质谱联用(GC/MS)检测结果表明,几种工业油品都得到了极好的加氢提质,芳烃深度甚至完全加氢,LTCT中的杂原子尤其是氧原子得到了很好的脱除。以300 oC甲醇热溶3 h获得其甲醇热溶油(MSP)作为劣质油品原料在200 oC进行加氢反应实验得到加氢转化产物(HMSP),采用热重(TG)和XPS分析XL及其甲醇热溶残渣(RXL),采用FTIR对XL、RXL、MSP和HMSP进行检测,研究各样品中官能团的变化。MSP和HMSP中物质的结构信息通过GC/MS和正负模式电喷雾离子源傅立叶离子回旋共振质谱(ESI FT-ICR MS)进行检测。结果表明,MSP中富含芳环以及杂原子化合物,而HMSP的GC/MS可测物都是链烷烃和环烷烃。ESI FT-ICR MS分析表明MSP中的含氧、氮物种经过加氢转化后明显减少。
[Abstract]:The hydrogenation of aromatics and aryl ethers is a key issue in the utilization of heavy carbon resources. The development of highly active supported metal catalysts is the key technology for the conversion of aromatics and aryl ethers, and nickel is the main component of hydrogenation conversion catalysts for aromatic compounds. Nickel carbonyl is decomposed directly to produce nickel particles with excellent dispersion at lower temperature, but the volatilization temperature of nickel carbonyl is low, so it is very difficult to decompose on the carrier. In this paper, Ni / Z _ 5A supported nickel catalyst was prepared in autoclave by in-situ decomposition with nickel carbonyl as the precursor, 5A molecular sieve Z5A as the carrier and ether as the solvent. The catalyst was characterized by a series of characterization, I. e., transmission electron microscopy (TEM) and electron dispersive electron spectroscopy (EDS) and X-ray diffraction (EDS). The results show that the metal loading is low, and the temperature programmed desorption of H _ 2-TPRH _ 3 is H _ 3-TPD _ (3), photoelectron spectroscopy (XPS) XPS ~ (-), Fourier transform Infrared Spectrometer (FTIR), etc., and the results show that the metal loading is relatively low. It was well dispersed on molecular sieve and even loaded in amorphous form, and the metal nickel interacted strongly with the support. The hydrogenation of 9- phenylanthracene and phenyl benzyl ether over Ni/Z5A catalyst at different temperatures was investigated. It was found that Ni/Z5A had a good hydrogenation effect on 9- phenylanthracene and phenyl benzyl ether at 200oC. The main products of 9- benzene anthracene and methylcyclohexane. Ni- / Z5A have bifunctional properties: activating H2 to form diatomic active hydrogen, second, dissociating H _ 2 from H _ 2 to dissociating H from Ni/Z5A and adsorbing H _ 2 on Ni/Z5A, based on this mechanism, Using 1-naphthol and dibenzyl ether OBMDBas as substrates at 200oC, the main products of 1-naphthol were tetrahydronaphthalene and decalin OBMDB, which were mainly methyl cyclohexane and toluene, and the main products of 1-naphthol were tetrahydronaphthalene and decahydronaphthol OBMDB. The mechanism of Ni/Z5A is used to explain that. Ni- / Z5A can be reused many times. The reason for the decrease of conversion is the agglomeration of loaded nickel particles caused by long time reaction. In order to explore the industrial application value of the catalyst, the hydrogenation conversion of low temperature coal tar (LTCT), high temperature coal tar (HTCTT) and bitumen volatile (PVP) was catalyzed by Ni/Z5A respectively. The results of gas chromatography / mass spectrometry (GC / MS) detection showed that, Several kinds of industrial oils have been obtained excellent hydrogenation quality, aromatic depth and even the complete hydrogenation of LTCT heteratomic atoms, especially oxygen atoms have been well removed. Taking 300oC methanol as raw material for hydrogenation at 200oC for 3 h, the hydrogenation conversion product was obtained. XL and its methanol residue were analyzed by thermogravimetric analysis (TG) and XPS. FTIR was used to detect RXLMSP and HMSP. The changes of functional groups in the samples. MSP and the structure information of the substances in HMSP were detected by GC/MS and Fourier Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR MS) of positive and negative mode electrospray ionization. The results showed that the MSPs were rich in aromatic rings and hetero-atomic compounds, while the GC/MS detectable compounds of HMSP were alkanes and cycloalkanes. ESI FT-ICR MS analysis showed that the oxygen content in MSP was significantly reduced, and the nitrogen species were reduced after hydrogenation.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36

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