Ab Initio Calculation of Rate Constants for Molecule-Surface Reactions with Chemical Accuracy.
Ab Initio Calculation of Rate Constants for Molecule-Surface Reactions with Chemical Accuracy.
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DOI：
10.1002/anie.201601534
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发表时间：
2016-04-18
期刊：
影响因子：
--
通讯作者：
Sauer J
中科院分区：
文献类型：
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作者：
Piccini G;Alessio M;Sauer J
对具有数百个原子的系统的反应速率常数进行从头开始预测，其精度可与实验相媲美，这是计算量子化学的一个挑战。我们提出了一种分而治之的策略，该策略不同于通过包含色散的标准密度泛函理论获得的势能面。通过反应位点的波函数型计算来细化反应物和过渡结构的能量。热效应和熵是根据振动配分函数计算的，并且针对每种振动模式分别计算非谐振频率。该方法适用于工业相关催化过程的关键反应，即小烯烃在沸石上的甲基化。计算的反应速率常数（自由能）、指前因子（熵）和焓垒表明，我们的计算策略产生的结果与化学精度限制（小于一个数量级）内的实验一致。
The ab initio prediction of reaction rate constants for systems with hundreds of atoms with an accuracy that is comparable to experiment is a challenge for computational quantum chemistry. We present a divide‐and‐conquer strategy that departs from the potential energy surfaces obtained by standard density functional theory with inclusion of dispersion. The energies of the reactant and transition structures are refined by wavefunction‐type calculations for the reaction site. Thermal effects and entropies are calculated from vibrational partition functions, and the anharmonic frequencies are calculated separately for each vibrational mode. This method is applied to a key reaction of an industrially relevant catalytic process, the methylation of small alkenes over zeolites. The calculated reaction rate constants (free energies), pre‐exponential factors (entropies), and enthalpy barriers show that our computational strategy yields results that agree with experiment within chemical accuracy limits (less than one order of magnitude).