Ab initio coverage-dependent microkinetic modeling of benzene hydrogenation on Pd(111),Catalysis Science & Technology

当前位置： X-MOL 学术 › Catal. Sci. Technol. › 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.)

Ab initio coverage-dependent microkinetic modeling of benzene hydrogenation on Pd(111)
Catalysis Science & Technology ( IF 4.4 ) Pub Date : 2017-09-12 00:00:00 , DOI: 10.1039/c7cy00962c
Maarten K. Sabbe _{1,

2,

3,

4} , Gonzalo Canduela-Rodriguez _{1,

2,

3,

4,

5} , Jean-François Joly _{5,

6,

7} , Marie-Françoise Reyniers _{1,

2,

3,

4} , Guy B. Marin _{1,

2,

3,

4}

Affiliation

The effect of hydrogen coverage on the kinetics of benzene hydrogenation on Pd(111) has been investigated with optPBE-vdW density functional theory calculations and a coverage-dependent microkinetic model. The dominant reaction path consists of the consecutive hydrogenation of carbon atoms located in ortho positions relative to the previously hydrogenated carbon atom, independent of the hydrogen coverage. Increasing the hydrogen coverage destabilizes all surface species, which leads to weaker adsorption and increased rate coefficients for the hydrogenation steps due to stronger destabilization of reactants than transition states. The catalytic activities simulated using the constructed coverage-dependent microkinetic model exceed those obtained using a low-coverage microkinetic model by several orders of magnitude and are comparable to experimentally observed activities. The rate coefficients to which the global rate is most sensitive depend on the reaction conditions and differ from those calculated using low coverage kinetics. Therefore, properly accounting for coverage dependence on the kinetics and thermodynamics of catalytic hydrogenation reactions is not only required for an accurate DFT-based prediction of the catalytic activity but also for a correct understanding of the reaction mechanism.

中文翻译：

从头算覆盖范围内苯对Pd（111）加氢的微观动力学模型

使用optPBE-vdW密度泛函理论计算和覆盖率依赖性微动力学模型研究了氢覆盖率对Pd（111）上苯加氢动力学的影响。主要的反应路径包括位于邻位的碳原子的连续氢化相对于先前氢化的碳原子的位置，与氢的覆盖率无关。氢覆盖率的增加使所有表面物质不稳定，这导致氢化物的吸附较弱，并且由于反应物的稳定性比过渡态要强，因此氢化步骤的速率系数也增加。使用构建的依赖于覆盖的微动力学模型模拟的催化活性比使用低覆盖率微动力学模型获得的催化活性高几个数量级，并且与实验观察到的活性相当。全局速率最敏感的速率系数取决于反应条件，并且与使用低覆盖率动力学计算的速率系数不同。所以，

更新日期：2017-11-14

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11