硫化钼基材料表面配位环境和协同效应对合成气选择性调控的理论研究

Improving the efficiency of carbon resources utilization is an urgent task for sustainable development of society and environmental change. The highly efficient selective conversion of syngas is the important way to optimize carbon resource utilization. Several main problems that exist in syngas conversion include the low efficiency of catalysts and poor selectivity toward high additional value products, etc. The key to solve these problems lies in the development of new materials and the elaborate design of their atomic and electronic structure. This project chooses novel two-dimensional layered MoS2 based materials, and investigates the effect of various surface structure such as the morphology of surface S vacancy, Mo edge, S edge and transition metal additives (such as Co, etc.) on syngas conversion (including CO activation and hydrogenation, etc.) using density functional theory calculations and micro-kinetic simulation, in an effort to reveal the role of the active sites of Mo and S, etc. and the tuning principles of additives. Combined with controlled material synthesis and in-situ characterization, we aim to investigate the micro mechanism of syngas conversion on the surfaces of MoS2 based catalysts under realistic reaction conditions (high coverages), and establish the fundamental principles for tuning selectivity (lower alcohols and alkanes ) by coordination environment and synergistic effect on the surfaces of MoS2 based catalysts at the atomic scale. This work will provide a theoretical guidance for highly efficient selective syngas conversion on non noble metal materials.

提高碳资源利用效率，是缓解环境和气候问题、实现社会可持续发展的当务之急。实现合成气高效选择性转化是优化碳资源利用的重要途径。目前合成气转化的主要问题有催化剂效率低，高附加值产物的选择性差等。解决这些问题的关键在于催化新材料的开发及其表面原子/电子结构的精准设计。本项目拟选取新型的二维层状MoS2基材料，利用密度泛函理论计算和微观动力学模拟研究这类材料表面各种结构单元如面内S空位的形貌、Mo边、S边及过渡金属助剂（如Co等）对合成气转化中各基元过程，包括CO活化、加氢等的影响，揭示Mo、S等活性位点的作用及助剂的调控机制。并与材料合成和原位表征合作，致力于在更接近真实的反应条件下（模拟高覆盖度），研究MoS2基材料表面上合成气转化微观机理，从原子尺度建立材料表面配位环境和协同效应对选择性（低碳醇、低碳烷烃等）调控的内在规律，为利用非贵金属材料实现合成气高效选择性转化提供理论指导。

提高碳资源利用效率，是缓解环境和气候问题、实现社会可持续发展的有效途径。CO、CO2高效选择性转化是优化碳资源利用的重要途径。目前，这些碳资源利用过程的主要问题有催化剂效率低，高附加值产物的选择性差等。解决这些问题的关键在于催化新材料的开发及其表面原子/电子结构的精准设计。本项目选取新型的二维层状MoS2基材料，利用密度泛函理论计算和微观动力学模拟研究了这类材料表面各种结构单元如基面、Mo边、S边及过渡金属助剂对CO/CO2加氢中各基元过程，包括H2活化、C-O键断裂及加氢等的影响，揭示了Mo、S等位点的作用及助剂的调控机制，识别了MoS2表面分子吸附和反应活性描述符，发展了覆盖度依赖的微观动力学方法，建立了表面配位环境和协同效应对活性、选择性（低碳醇、烷烃）调控的内在规律，为利用非贵金属材料实现碳资源高效选择性转化提供理论指导。另外，通过与实验研究合作，识别了CO电化学还原的活性位，实现了常温常压下高选择性制取乙烯；并识别了O-H键活化的关键因素。项目资助期间，共计发表SCI论文13篇，包括申请人以（共同）一作或通讯在Angew. Chem. Int. Ed.，ACS Catal.和Chem. Sci.等期刊发表论文10篇。其中Angew. Chem. Int. Ed. 2020, 59, 154同时入选Hot paper和Frontispiece，Chem. Sci. 2020, 11, 4119, 2020同时入选Chemical Science HOT Article Collection和2020 ChemSci Pick of the Week Collection；协助培养毕业博士研究生5名。