【作者】 王慧敏；

【导师】 苏海全；

【作者基本信息】 内蒙古大学 ， 生态学， 2012， 博士

【摘要】 生态环境的不断恶化、全球变暖的持续加剧及能源的日趋枯竭是现今人类面临和亟待解决的三大中心问题。从保护生态环境出发,寻求高效、清洁的替代能源和研究开发环保、低碳、可持续的绿色能源生产方式是解决这些问题和实现人类社会可持续发展的唯一途径。以CO、CO2气体作为碳源,通过催化加氢制取低碳醇,具有原料来源广泛、能源利用率高、制得的低碳醇燃料使用过程中有毒气体及温室气体排放量少等特点,被认为是最有应用前景的能源生产及利用的新途径之一。目前,CO、CO2催化加氢制低碳醇仍然面临着转化率较低、醇类产物产率及选择性偏低等问题,还没有形成产业化。高效催化剂的研制与开发是解决这些问题的根本途径。对CO、CO2催化加氢制低碳醇催化反应而言,加强催化剂中活性组分与助剂之间的相互作用以及有效控制活性组分在载体表面的分散状态是提高催化剂催化活性的关键。将异金属配位聚合物作为前驱物应用于上述非均相催化体系,可以实现有效增强活性组分与助剂之间的相互作用以及控制活性组分的分散,从而达到提高催化剂活性的目的。本论文首次选用CO、CO2催化加氢制低碳醇催化剂的活性组分金属元素(贵金属元素铑)及助剂金属元素(碱金属元素和稀土元素)与吡啶羧酸类有机配体共同构建了一系列具有不同组成、结构及功能的配位聚合物,将它们作为制备催化剂的前驱物,创造性地将配位聚合物应用于CO、CO2加氢制取低碳醇催化体系。综合评价了它们对CO、CO2催化加氢制低碳醇的催化活性,及整个催化过程中温室气体CO2的利用水平与温室气体CH4、CO2的排放水平。本文还对上述催化剂进行了CH4-CO2催化重整反应的催化活性评价,为实现CO、CO2催化加氢制低碳醇工艺与CH4-CO：催化重整工艺的有机耦合提供了理论与现实依据,同时也为尽可能消除CO、CO2催化加氢制低碳醇过程中温室气体的排放提供了可行的解决方案。主要工作如下1.设计并合成了八个新型配位聚合物,包括：五个Rh-M型双金属配位聚合物RhLi(PDA)2(H2O)2·2H2O (1)、RhNa(PDA)2(H2O)2(2)、RhK(PDA)2(3)、 RhCe(BPTA)(H2O)4Cl2(4)、RhEu(BPTA)(H2O)4Cl2(5);两个单一金属离子的超分子配位聚合物Rh(BPDA)(HBPDA)(6)、Co(BPDA)(HBPDA)(7)及一个具有新颖的一维锁链结构和优良的光致发光性能的稀土配位聚合物[Eu2(BPDA)3(H2O)]·6H2O (8)。对所有化合物进行了单晶结构及性质的表征。2.选用六个含铑配位聚合物作为前驱物,制备了新型铑基催化剂,并应用于CO加氢制取低碳醇催化过程。研究了前驱物的组成及结构对催化性能的影响。选用以一维配位聚合物RhLi(PDA)2(H2O)2·2H2O(1)为前驱物的催化剂1-SiO2催化CO-CO2混合气加氢制低碳醇反应,研究了反应条件对催化性能的影响。4.评估了CO-CO2混合气催化加氢制低碳醇过程对温室气体CO2的利用水平,及CO、CO2催化加氢制低碳醇催化过程中温室气体CH4、CO：的排放水平。结果表明,所使用的6个CO、CO2加氢制低碳醇催化剂的温室气体排放量均处在较低的水平,均为是绿色环保型催化剂。5.进行了CH4-CO2催化重整制合成气的实验,并模拟了CO、CO2催化加氢制低碳醇工艺与CH4-CO2催化重整工艺耦合的生产模式。提出CO、CO2加氢制低碳醇催化过程实现温室气体进一步减排的策略,为实现CO、CO2催化加氢制低碳醇工艺与CH4-CO2重整制合成气工艺的耦合摸索经验并提供了有利的数据支撑。更多还原

【Abstract】 The ecological environment deterioration, global warming and energy depletion are the most important problems that must be resolved urgently in the world. The only way to solve these problems is to explore efficient clean alternative energy with sustainable and environment-friendly production mode. The alcohol fuel is often regarded as a potential renewable clean alternative fuel to gasoline. The synthesis of mixed alcohols through the hydrogeneration of CO or CO2is widely considered to be one of the most prospective energy production modes because it has many advantages, such as the various choices of raw materials, the high energy efficiency and the less emissions of toxic and greenhouse gas during the consumption of the alcohol fuels. However, the industrialization of alcohol fuel synthesis through the hydrogenation of CO or CO2is still immature due to the low CO conversion and the low alcohol selectivity. The research and exploitation of more efficient catalysts are the most effective way to deal with these problems. For the synthesis of alcohol fuel through the hydrogenation of CO or CO2, the critical factor to improve the catalytic activity is to strengthen the interaction between active components and promoted metals as well as to control their dispersion states on the supports effectively. And these could be solved by introducing heterometallic coordination polymers as catalytic precursors into the above-mentioned system of alcohol production.Based on the above considerations, in this thesis, a series of heterometallic coordination polymers with different compositions, structures and functions were firstly constructed by rhodium ions, alkali-metal ions, lanthanide ions and pyridine carboxylic ligands. It should be noted that the alkali-metal ions and the lanthanide ions are always used as promoters in rhodium-based catalysts for the hydrogenation of CO or CO2. The synthesized Rh-M heterometallic coordination polymers as catalytic precursors were creatively introduced into the above-mentioned hydrogenation system to prepare corresponding catalysts. During the exploration of the catalytic performances for the hydrogenation of CO or CO2, the CO2utilization level and the greenhouse gases (CH4and CO2) emission level were evaluated as well. Moreover, the catalytic performances of these new-type rhodium-based catalysts for CH4and CO2reforming to syngas were explored, which provides the theoretical and practical basis for the combination of CO or CO2hydrogenation technology and CH4and CO2reforming technology. The study also provides a feasible solution for eliminating greenhouse gas emissions as much as possible during the hydrogenation process of CO or CO2.The main work is as follow.1. Eight new compounds were synthesized, including five Rh-M coordination polymers (RhLi(PDA)2(H2O)2-2H2O (1), RhNa(PDA)2(H2O)2(2), RhK(PDA)2(3), RhCe(BPTA)(H2O)4Cl2(4) and RhEu(BPTA)(H2O)4Cl2(5)), two novel supermolecules (Rh(BPDA)(HBPDA)(6) and Co(BPDA)(HBPDA)(7)) and a lanthanide coordination polymer (Eu2(BPDA)3(H2O)]·6H2O (8))(H2PDA=pyridine-2,6-dicarboxylic acid; H4BPTA=2,2’-bipyridine-3,3’,6,6’-tetracarboxylic acid; H2BPDA=2,2’-bipyridine-6,6’-dicarboxylic acid). All the compounds were structurally characterized by single-crystal X-ray diffraction, and the properties of all compounds were examined.2. Six new-type rhodium-based catalysts were prepared using the six Rh-based coordination polymers as precursors, respectively, and their catalytic performances of CO hydrogenation were tested. The effects of the structures, the compositions of the precursors as well as the reaction conditions on catalytic performance were also explored. Furthermore, in order to explore the effects of the reaction conditions on catalytic performance, the catalyst1-SiO2derived from RhLi(PDA)2(H2O)2-2H2O (1) was used to synthesize alcohols through hydrogenation of CO and CO2.4. The CO2utilization level was evaluated during the synthesis of alcohols from the mixture of CO, CO2and H2, and the greenhouse gases (CH4and CO2) emission level was also evaluated during the synthesis of alcohols from the mixture of CO and H2and the mixture of CO, CO2and H2. The results show that all the catalysts gave the very low level of greenhouse gases emission, and they can be considered as green and environment-friendly.5. The experiment regarding CH4and CO2reforming to syngas was performed, and a production mode was simulated by coupling of the CO or CO2hydrogenation technology with CH4and CO2reforming process. The strategies of greenhouse gas emission reduction for the CO or CO2hydrogenation process were also proposed. The results provide experimental experiences and useful data to achieve the real combination of CO or CO2hydrogenation technology and CH4-CO2reforming technology.更多还原