淬冷骨架铜催化稠环芳烃选择性加氢及反应机理研究

Selective catalytic hydrogenation of polycyclic aromatic hydrocarbons(PAHs) has become a hotspot of current research in sustainable development of chemistry on account of the functionalized products which could be important intermediates for pharmaceuticals, herbicides and fine chemicals. However, it is generally considered a challenging process due to the key problems listed below: There are difficulties in controlling the selectivity effectively for portion of the substrates, especially with a relative lack of theoretical study on the interaction between catalyst and substrate. The selective hydrogenation of PAHs over skeletal Cu will be consequently investigated in this project according to the high unsaturation of quenching alloy surface and the functional group adsorption selectivity on the surface of catalyst. The selective hydrogenation of naphthalene to tetrahydronaphthalene over skeletal Cu is chosen as a model reaction for mechanism study, and the adsorption modes of naphthalene and tetrahydronaphthalene on the catalyst surface will be researched under the reaction energy state by in-situ characterization and aided theoretical calculation. Then selective hydrogenation of other substituted PAHs with symmetric, asymmetric and heterocyclic structures will be studied systematically, and the influences of substituent, substituted site and heteroatom type on the product distribution may be clarified. The interaction mechanism between catalyst and the functional groups will be explored in order to reveal the basic rules of the PAHs' selective hydrogenation, which will provide the theoretical proofs for controllable synthesis of single product and rational design of catalyst.

稠环芳烃的选择性催化加氢是当前精细化学品绿色合成的一个研究热点，部分加氢产品具有突出的应用价值。目前存在的关键问题是稠环芳烃的选择性催化加氢无法得到有效调控，尤其对底物与催化剂相互作用的机理研究相对匮乏。本项目基于淬冷金属表面的高度不饱和性及底物官能团在催化剂表面的吸附选择性，开展淬冷骨架铜催化稠环芳烃选择性加氢的研究。通过原位表征技术辅以理论计算，考察反应能态下模型底物萘和中间体四氢萘在催化剂表面的吸附模式，解释反应机理。在此基础上，研究不同基团取代的对称、非对称结构稠环芳烃及杂稠环芳烃的选择性加氢反应规律，确定取代基团、取代位点及杂原子种类对产物分布的影响，探索催化剂与底物官能团的相互作用机制，以揭示稠环芳烃选择加氢的基本规律，为催化剂的理性设计及单一产物的可控制备提供理论依据。

稠环芳烃是从煤化工的焦油中提取的重要产品，其选择性催化加氢是有机合成中的一类重要反应，加氢产物在化工领域应用广泛。目前存在的关键问题是稠环芳烃的选择性催化加氢无法得到有效调控，尤其对底物与催化剂相互作用的机理研究相对匮乏。本项目采用淬冷法制备了骨架铜催化剂，利用XRD，SEM，N2吸附-脱附，XPS等手段对催化剂的微观形貌及结构进行了表征；采用Turbomole量化计算程序对反应物、中间体、产物的分子结构进行了优化。在此基础上，探索了骨架铜催化对称、非对称结构稠环芳烃及杂稠环芳烃的选择性加氢的反应规律，研究了取代基团、取代位点及杂原子对产物分布的影响规律，从分子的空间位阻、产物能量分布、电子效应三方面对反应机理进行了讨论，从而为催化剂的理性设计及单一产物的可控制备提供了理论依据。该项目的顺利实施对于煤化工下游产品的综合利用具有重要意义。