选择性加氢反应的高效金属纳米催化剂研究

The selective hydrogenation of specific unsaturated functional groups is an industrially important process for the synthesis of pharmaceuticals, polymers, herbicides, and other substances and fine chemicals, so there is a strong incentive to develop effective catalysts for the hydrogenation reactions. The catalytic activity and selectivity of a catalyst are mainly determined by its sizes, facets, compositions and interfacial properties, because these parameters could make a combined impact on the adsorption configuration and adsorption energy of the substrates, which are commonly regarded as a large simplification of catalytic properties. In recent years, the size control of catalysts in selective hydrogenation reactions has reached a relatively high level, together with the extensive development of the mechanism study for this reaction. However, compositions and interfacial properties of catalysts cannot yet be finely tuned to date. In addition, direct observational evidences for the cleavage and formation of chemical bonds or the existence of certain intermediates, on atomic and molecular scale, are still limited. Based on the above considerations and our previous work, we attempt to develop a methodology of controlled synthesis of metal nanocatalysts used for selective hydrogenation, with an ultimate goal to establish the structure-activity relationship (SAR) and atomic and molecular model of the catalytic process...The proposed research will be organized into three thrusts:..(1) Develop and complete the methodology of controlled synthesis of metal nanocrystals. This work will focus on the fine modulation over the compositions as well as surface and interfacial properties of metal nanocrystals, through analyzing the connection between thermodynamic/kinetic conditions and the nanocrystal growth...(2) Study the bond-selecting process and regulation mechanism of selective hydrogenation with the existence of multiple unsaturated functional groups. We will systematically investigate the hydrogenation process with the help of in situ spectroscopy techniques, including in situ infrared and Raman spectroscopy, combined with the density functional theory. ..(3) Establish the SAR and seek the optimal nanocatalysts towards selective hydrogenation with high activity and selectivity. We will test the performance of catalysts, and conclude the SAR between the selective hydrogenation and intrinsic nanocrystal features, including sizes, facets, compositions and interfacial properties. Based on the above works, we will finally screen out specialized catalysts towards the hydrogenation of unsaturated functional groups, such as nitro compounds, carbonyls, olefins, and aromatic rings.

特定不饱和基团的选择性加氢反应在化工生产和药物合成等方面有着广泛的应用。针对这类反应，催化剂的尺寸、晶面、组分和界面共同影响着加氢底物分子的吸附构型和吸附能，是调控加氢反应活性和选择性的重要因素。近年来，针对选择性加氢催化剂的尺寸控制已经达到了较高的水平，也发展出了一些研究该反应机理的方法，但当前的研究还缺乏精细调控催化剂（合金）组分和表界面特征的有效手段，以及鲜有在原子分子层面针对选择性加氢反应中间体以及化学键生成和断裂过程的直接观测证据。在本项目中，我们拟通过分析各种热力学和动力学参数与纳米晶催化剂可控生长之间的关系，发展精细调控催化剂组分和表界面等结构参数的有效手段，深入研究多种不饱和基团共存的选择性加氢反应关键过程与调控机制，凝练出催化剂针对选择性加氢反应的构效关系，最终筛选出针对硝基、羰基、碳碳双键和芳香环四种基团选择性加氢的高效催化剂。

特定不饱和基团的选择性加氢反应在化工生产和药物合成等方面有着广泛的应用。项目组围绕选择性加氢反应金属纳米催化剂的（合金）组分和表界面特征调控、原子分子层面上的催化机理探索和加氢反应催化性能优化等方面开展研究。借助可控合成基础、原位表征技术和理论计算深入地揭示金属纳米晶催化硝基、羰基、碳碳双键等不饱和基团选择性加氢反应的关键过程和调控机制，在原子分子层面上设计和优化针对特定不饱和基团选择性加氢的金属纳米催化剂，并以此优化加氢反应的活性和选择性，最终筛选出针对硝基、羰基、碳碳双键等不饱和基团选择性加氢的高效催化剂。项目组还针对二氧化碳加氢反应中碳氧双键加氢过程的关键调控机制开展研究，实现高选择性二氧化碳加氢制甲醇。项目执行期间，在《自然·纳米技术》、《自然·能源》、《自然·通讯》等国际顶级学术期刊发表研究论文共44篇，申请发明专利34项。