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首页> 外文学位 >Synthesis, characterization, and catalytic activity of silica supported homo- and heterodinuclear metal complexes.
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Synthesis, characterization, and catalytic activity of silica supported homo- and heterodinuclear metal complexes.

机译：二氧化硅负载的同核和异核金属配合物的合成，表征和催化活性。

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摘要

Stable dinuclear complexes bis(heptane-2,4,6-trionato)dicopper(II) [Cu 2(daa)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicopper(II) [Cu2(dba)2], bis(1,5-diphenyl-1,3,5-pentanetrionato)dicobalt(II) [Co2(dba)2], and [6,11-dimethyl-7,10-diazahexadeca-5,11-diene-2,4,13,15-tetranato(4-)-N7N10O4O13;O2O4O13O15] copper(II)cobalt(II) [(CuCo(daaen)] were supported on Cab-O-Sil by the batch impregnation technique. The supported samples were characterized by UV-Vis, elemental analysis, X-ray powder diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and thermal gravimetric analysis (TGA). Elemental analysis and TGA data confirm that the Cu2(daa) 2 complex loses one of its coordinated ligands upon adsorption onto silica in THF at greater than 4.43 wt% Cu loading. By contrast, at all Cu loadings the Cu2(dba)2 complex was adsorbed on the silica surface in CH2Cl2 without loss of ligand. XRD and DRIFTS results confirmed the formation of Cu2(dba)2 multilayer films on the Cab-O-Sil surface for samples containing greater than 2.64 wt% copper. The dinuclear cobalt complex and copper-cobalt complex also do not lose their coordination ligands upon adsorption on the surface. These two metal complexes are amorphous and did not produce XRD patterns. However, DRIFTS results confirm that the binuclear cobalt complex and the copper-cobalt complex begin forming multilayer films between 1.21and 2.53 wt% Cu.;The Cu2(dba)2/silica precatalysts were subsequently converted to the catalysts by decomposing the organic ligands at 450 degrees Celsius followed by activation with 2% H2 at 250 degrees Celsius and were evaluated for methanol synthesis and methanol decomposition reactions. Kinetic studies demonstrated that the 3.70% Cu/silica[Cu2(dba) 2] catalyst is more active for methanol decomposition than it is for methanol synthesis. The supported dinuclear cobalt and copper-cobalt precatalysts were converted to the catalyst by heating at 450 degrees Celsius followed by activation of the catalysts with 50% H2. Four different catalysts, 3.5% Co/silica[Co2(dba)2], 6.7% Co/silica[Co2(dba) 2], 2.3% Co/silica[CuCo(daaen)], and 5.5% Co/silica[Co2(daa) 2] were evaluated for the Fischer-Tropsch reaction at 350 degrees Celsius in a batch reactor. The supported binuclear cobalt catalyst produced C 1-C7 alkanes and a significant amount of Co 2. By contrast, the catalyst formed from heterobinuclear CuCo(daaen) showed the ability to convert syngas to aromatics with a narrow product distribution. In addition, the 6.7% Co/silica[Co2(dba)2] multilayer catalysts have above 98% conversion rates and 60% liquid hydrocarbon selectivity in a flow reactor.
机译：稳定的双核配合物双（庚烷-2,4,6-三萘并）双铜（II）[Cu 2（daa）2]，双（1,5-二苯基-1,3,5-戊烷三并萘）双铜（II）[Cu2 （dba）2]，双（1,5-二苯基-1,3,5-戊烷三酮）二钴（II）[Co2（dba）2]和[6,11-二甲基-7,10-二氮杂十六烷基-5，通过间歇浸渍技术将11-二烯-2,4,13,15-四萘并（4-）-N7N10O4O13; O2O4O13O15]铜（II）钴（II）[（CuCo（daaen）]]负载在Cab-O-Sil上通过UV-Vis，元素分析，X射线粉末衍射（XRD），漫反射红外傅里叶变换光谱（DRIFTS）和热重分析（TGA）对负载的样品进行了表征，元素分析和TGA数据证实了Cu2 （daa）2络合物在以超过4.43 wt％的铜负载量吸附到THF中的二氧化硅上时会失去其配位体之一，相比之下，在所有铜负载量下，Cu2（dba）2络合物无损失地吸附在CH2Cl2中的二氧化硅表面上XRD和DRIFTS结果证实了Cu2（dba）2多层膜的形成对于包含大于2.64 wt％铜的样品，请在Cab-O-Sil表面上进行。双核钴络合物和铜-钴络合物在吸附到表面时也不会失去配位配体。这两种金属络合物是无定形的，没有产生XRD图案。然而，DRIFTS结果证实了双核钴配合物和铜钴配合物开始在1.21和2.53 wt％的Cu之间形成多层膜。随后，Cu2（dba）2 /二氧化硅预催化剂通过将有机配体在200℃分解而转化为催化剂。 450摄氏度，然后在250摄氏度下用2％H2活化，并进行甲醇合成和甲醇分解反应的评估。动力学研究表明，相对于甲醇合成，3.70％Cu /二氧化硅[Cu2（dba）2]催化剂对甲醇的分解更具活性。通过在450℃加热，然后用50％H 2活化催化剂，将负载的双核钴和铜-钴预催化剂转化为催化剂。四种不同的催化剂：3.5％Co /二氧化硅[Co2（dba）2]，6.7％Co /二氧化硅[Co2（dba）2]，2.3％Co /二氧化硅[CuCo（daaen）]和5.5％Co /二氧化硅[Co2 （daa）2]在间歇反应器中在350摄氏度下进行了费-托反应的评估。负载型双核钴催化剂可生成C 1-C7烷烃和大量的Co2。相比之下，由异双核CuCo（daaen）形成的催化剂显示出能够将合成气转化为具有狭窄产物分布的芳烃的能力。另外，在流动反应器中，6.7％Co /二氧化硅[Co 2（dba）2]多层催化剂具有高于98％的转化率和60％的液态烃选择性。

著录项

  • 作者

    Ranaweera, Ankadage Samantha.;

  • 作者单位

    Mississippi State University.;

  • 授予单位 Mississippi State University.;
  • 学科 Chemistry Inorganic.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 207 p.
  • 总页数 207
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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