原位固体核磁共振方法的发展及在纳米界面催化研究中的应用

With the rapid development of controllable nano-catalyst synthesis approach, the fine regulation of the interfacial structure has been more and more attractive to the catalyst researchers. The characterization at atomic level of the interfacial microstructure and the reactive processing by solid-state NMR would provide significant information for designing and developing novel catalysts. In recent years, a number of NMR innovations have been developed, although these developments could accelerate the applications of solid-state NMR in catalytic materials research, they have also raised new challenges. In this project, we focus on the development of solid-sate NMR methodology to break through the limitations of current NMR hardware and spin system of interest, and on the development of high-temperature & high-pressure in-situ solid-state NMR equipment and technique to observe the structural changes and activation mechanism under the practical reaction conditions. By combining the designed solid-state NMR pulse sequences and the high-temperature & high-pressure in-situ NMR technique, the interfacial catalytic reaction can be studied at atomic level under the original reaction conditions, where the instant changes in reactants, intermediates can be tracked quantitatively. Finally, the activation mechanism of reactants on the surface of catalyst, as well the reaction mechanism, can be revealed, which would help to understand the relation between “structure” and “performance” of the nano interfacial catalysts. The successful implementation of this project is expected to open up new strategy for studies of nano-interfacial catalysts, and promote the developments of designing novel catalysts.

随着纳米可控合成方法的快速发展，催化剂表界面结构的精细调控越来越受到催化领域科学家的重视，固体NMR在原子水平上对其微观结构和活化历程的研究为新型催化剂的制备和研究提供了极为宝贵的技术支持。近些年NMR谱仪技术不断地发展和创新，一方面加速了固体NMR在催化材料研究中的应用，另一方面对于常规固体NMR方法的实施也提出了新的挑战。本项目拟采用近年新兴的NMR谱仪技术，设计和发展新型固体核磁共振方法，以突破当前NMR硬件和自旋核体系条件的限制，并开发耐高温高压原位固体核磁共振相关设备及方法。结合发展的固体NMR脉冲方法与原位高温高压固体NMR技术，应用于实际表界面催化反应中；在原始反应条件下跟踪观测反应物、中间体的实时变化，进而揭示活化历程和反应机理，在原子水平上理解和揭示界面催化剂的“构－效”关系。本项目的顺利实施将会为纳米界面催化的研究开辟新的路径，并为催化剂的研发、构筑提供新的思路。

多相催化中重要的化学反应往往依赖于表面催化作用，纳米界面催化材料的表面的微观结构、活化性能及催化机理的研究，对于设计高效、稳定的催化材料具有重要的意义。本项目以表界面催化体系为研究对象，针对多相催化反应中的关键科学问题，通过高分辨固体核磁共振技术为主要表征手段，研究了基于分子筛、氧化物催化剂的碳资源小分子转化反应体系，从表界面微观结构、活性位、催化反应机理等多方面揭示催化反应过程的微观机制，进而理解催化剂结构与催化反应效率和催化剂稳定性之间的关联。并且，针对NMR谱学技术在催化体系实际研究应用中面临的重要挑战，设计和发展了多种新型固体核磁共振谱学方法，以及开发了高温、高压原位固体核磁共振动态表征技术，进一步拓展了固体核磁共振在表界面纳米催化中的应用。