当前位置: X-MOL 学术ChemCatChem › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
An In‐Depth Mechanistic Study of Ru‐Catalysed Aqueous Methanol Dehydrogenation and Prospects for Future Catalyst Design
ChemCatChem ( IF 3.8 ) Pub Date : 2020-03-30 , DOI: 10.1002/cctc.202000057
Nitish Govindarajan 1 , Vivek Sinha 2 , Monica Trincado 3 , Hansjörg Grützmacher 3 , Evert Jan Meijer 1 , Bas Bruin 2
Affiliation  

Herein we provide mechanistic insights into the dehydrogenation of aqueous methanol catalysed by the [Ru(trop2dae)] complex (which is in‐situ generated from [Ru(trop2dad)], trop2dad=1,4‐bis(5H‐dibenzo[a,d]cyclohepten‐5‐yl)‐1,4‐diazabuta‐1,3‐diene), established by density functional theory based molecular dynamics (DFT‐MD) and static DFT calculations incorporating explicit solvent molecules. The aqueous solvent proved to participate actively in various stages of the catalytic cycle including the catalyst activation process, and the key reaction steps involving C−H activation and hydrogen production. The aqueous solvent forms an integral part of the reactive system for the C−H activation steps in the [Ru(trop2dae)] system, with strong hydrogen bond interactions with the anionic oxygen (RO, R=CH3, CH2OH, HCO) and hydride moieties formed along the reaction pathway. In contrast to the [Ru(trop2dad)] catalyst, C−H activation and hydrogen production does not proceed via a metal‐ligand cooperative pathway for the [Ru(trop2dae)] system. The pKa of the coordinated amine donors in these complexes provides a rationale for the divergent reactivity, and the obtained mechanistic information provides new guidelines for the rational design of active and additive free catalytic systems for aqueous methanol dehydrogenation.

中文翻译:

钌催化甲醇水脱氢的深度机理研究及未来催化剂的设计前景

本文中,我们提供了对由[Ru(trop 2 dae)]配合物(由[Ru(trop 2 dad)],trop 2 dad = 1,4-bis(原位生成)催化的甲醇水溶液脱氢的机理研究。5H-二苯并[a,d]环庚烯-5-基)-1,4-二氮杂丁-1,3-二烯),是通过基于密度泛函理论的分子动力学(DFT-MD)和静态DFT计算并结合了明确的溶剂分子而建立的。事实证明,水性溶剂可积极参与催化循环的各个阶段,包括催化剂活化过程以及涉及CH活化和产氢的关键反应步骤。水性溶剂构成了[Ru(trop 2DAE)]系统,具有与阴离子氧强氢键相互作用(RO -,R = CH 3,CH 2 OH,HCO)和沿反应途径形成氢化物的部分。与[Ru(trop 2 dad)]催化剂相反,CH活化和产氢不是通过[Ru(trop 2 dae)]系统的金属配体协同途径进行的。这些配合物中配位胺供体的pK a为不同的反应性提供了理论依据,所获得的机理信息为合理设计用于水性甲醇脱氢的活性和无添加剂催化体系提供了新的指导原则。
更新日期:2020-03-30
down
wechat
bug