富氮多孔金属有机骨架材料的气体吸附分离性能研究

Methane, the major component of natural gas, is not only a prevalent and inexpensive fuel for industry and residential use but also a useful C1 feedstock in chemical and petrochemical industry. For chemical and petrochemical applications, impurities in methane starting material may complicate the product isolation processes. Moreover, certain impurities may inhibit the conversion of methane. The major impurities in naturally occurring methane are C2 hydrocarbons (C2s). In addition, carbon dioxide is also present in natural gas in various amounts. It is, therefore, critical to remove C2s and CO2 from methane. Metal-organic frameworks (MOFs) possess potential application in C2s and CO2 capture, and much attention has been dedicated to improve their sorption and separation ability at room temperature. In this proposal, functionalized MOF materials can be obtained by assembly of designed tricarboxylic acid organic ligands with high Lewis basic sites and inorganic building blocks with open metal sites, and the C2s and CO2 capture ability can been enhanced in this system. This project aims to introduce elaborate functional active sites for the construction of porous MOFs through the strategies of“direct synthesis”, which will lead to the improved performances of modified MOFs. This investigation will help us understand the related information of crystal structures and functionalized sites, as well as the relationship between structures and properties, and the results of this research can provide theoretical basis and effective strategies for the synthesis of new porous materials.

甲烷作为天然气最主要的组成部分，不仅是易得的廉价工业燃料，而且是有用的C1化工原料。甲烷中的不纯成分不但使产物的分离复杂化还会抑制甲烷的转化。天然甲烷的主要杂质是C2碳氢化合物（C2s），其中也存在大量的二氧化碳，因此提纯天然气将C2s、二氧化碳与甲烷分离是至关重要的。金属有机骨架材料（MOFs）在C2s和二氧化碳捕获方面展现了潜在的应用价值，提高其在常温下的吸附和分离能力已成为关注的焦点。本项目通过合成高路易斯碱位的三羧酸配体作为有机组分连接具有活性金属中心的无机组分构筑功能化MOFs材料，增强MOFs对C2s和二氧化碳的相互作用，实现选择性吸附与分离。通过直接合成法向MOFs中引入功能位点，对其进行精心设计和剪裁，提高MOFs性能。本课题拟重点研究合成的MOFs材料结构与功能位点之间的相应信息，深入理解性能与结构之间的内在联系，为进一步合成新型多孔材料提供有效的策略和理论依据。

金属有机骨架材料（MOFs）在C2s和CO2捕获方面展现了潜在的应用价值，提高其吸附和分离能力已成为关注的焦点。本项目通过合成高路易斯碱位配体作为有机组分连接具有活性金属中心的无机组分构筑功能化MOFs材料，提升MOFs对C2s和CO2的吸附能力，实现选择性吸附与分离。我们水热合成了一例具有罕见nia拓扑结构的微孔钇MOFs材Y-H3TDPAT。该材料具有合适的孔道大小，孔道内壁上富含路易斯碱位，这对提升C2H2和CO2亲和能起到重要作用（吸附焓分别为38.2和30.9kJ·mol-1）。另外，理论计算表明被吸附的C2H2分子可以固定在两个三嗪环之间。该材料具有较高的C2H2/CH4和CO2/CH4选择性吸附能力，在天然气纯化方面具有潜在的应用价值。