Krieger Annika M, Kuliaev Pavel, Armstrong Hall Felix Q, Sun Dapeng, Pidko Evgeny A
Inorganic Systems Engineering Group, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands.
TheoMAT group, ChemBio Cluster, ITMO University, Lomonosova str. 9, St. Petersburg, 191002 Russia.
J Phys Chem C Nanomater Interfaces. 2020 Dec 10;124(49):26990-26998. doi: 10.1021/acs.jpcc.0c09953. Epub 2020 Nov 24.
The reaction medium and conditions are the key parameters defining the efficiency and performance of a homogeneous catalyst. In the state-of-the-art molecular descriptions of catalytic systems by density functional theory (DFT) calculations, the reaction medium is commonly reduced to an infinitely diluted ideal solution model. In this work, we carry out a detailed operando computational modeling analysis of the condition dependencies and nonideal solution effects on the mechanism and kinetics of a model ester hydrogenation reaction by a homogeneous Mn(I)-P,N catalyst. By combining DFT calculations, COSMO-RS solvent model, and the microkinetic modeling approach, the kinetic behavior of the multicomponent homogeneous catalyst system under realistic reaction conditions was investigated in detail. The effects of the reaction medium and its dynamic evolution in the course of the reaction were analyzed by comparing the results obtained for the model methyl acetate hydrogenation reaction in a THF solution and under solvent-free neat reaction conditions. The dynamic representations of the reaction medium give rise to strongly nonlinear effects in the kinetic models. The nonideal representation of the reaction medium results in pronounced condition dependencies of the computed energetics of the elementary reaction steps and the computed kinetic profiles but affects only slightly such experimentally accessible kinetic descriptors as the apparent activation energy and the degree of rate control.
反应介质和条件是决定均相催化剂效率和性能的关键参数。在通过密度泛函理论（DFT）计算对催化体系进行的最新分子描述中，反应介质通常简化为无限稀释的理想溶液模型。在这项工作中，我们对均相Mn(I)-P,N催化剂催化的模型酯加氢反应的机理和动力学，进行了关于条件依赖性和非理想溶液效应的详细原位计算建模分析。通过结合DFT计算、COSMO-RS溶剂模型和微观动力学建模方法，详细研究了多组分均相催化剂体系在实际反应条件下的动力学行为。通过比较在四氢呋喃溶液中以及无溶剂纯反应条件下模型乙酸甲酯加氢反应的结果，分析了反应介质及其在反应过程中的动态演变的影响。反应介质的动态表现导致动力学模型中出现强烈的非线性效应。反应介质的非理想表现导致基本反应步骤的计算能量学和计算动力学曲线对条件有明显的依赖性，但对诸如表观活化能和速率控制程度等实验可获取的动力学描述符影响较小。
