CHD3 Dissociation on the Kinked Pt(210) Surface: A Comparison of Experiment and Theory
CHD3 Dissociation on the Kinked Pt(210) Surface: A Comparison of Experiment and Theory
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DOI：
10.1021/acs.jpcc.9b03051
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发表时间：
2019-06-13
影响因子：
3.7
通讯作者：
Kroes, Geert-Jan
中科院分区：
文献类型：
--
作者：
Chadwick, Helen;Gutierrez-Gonzalez, Ana;Kroes, Geert-Jan
为了能够模拟在纳米颗粒的边角位置上被激活的多相催化反应，需要一种准确计算反应的活化势垒的方法。我们最近证明了用来描述CHD3在Ni(111)平面上解离的半经验比反应参数(SRP)密度泛函可以用来描述在阶梯状的铂(211)表面上的相同反应。在目前的工作中，我们比较了用King和Wells光束反射率技术测量的初始粘着系数和使用相同的SRP泛函计算的CHD3在650K扭曲的铂(210)表面上的分子动力学轨道的初始粘着系数。计算的粘着系数高估了实验确定的粘着系数，两条曲线之间的平均能量位移为13.6kJ/mol，比定义化学精度的4.2kJ/mol极限高出3倍以上。这表明，SRP泛函预测的活化势垒对于最低配位的扭结原子上的解离来说太低了，这是最低能量过渡态的位置，也是计算中大部分解离发生的地方。
To be able to simulate activated heterogeneously catalyzed reactions on the edge and corner sites of nanoparticles, a method for calculating accurate activation barriers for the reactions is required. We have recently demonstrated that a semiempirical specific reaction parameter (SRP) density functional developed to describe CHD3 dissociation on a flat Ni(111) surface is transferable to describing the same reaction on a stepped Pt(211) surface. In the current work, we compare initial sticking coefficients measured using the King and Wells beam reflectivity technique and calculated from ab initio molecular dynamics trajectories using the same SRP functional for CHD3 dissociation on a kinked Pt(210) surface at a temperature of 650 K. The calculated sticking coefficients overestimate those determined experimentally, with an average energy shift between the two curves of 13.6 kJ/mol, which is over a factor of 3 times higher than the 4.2 kJ/mol limit that defines chemical accuracy. This suggests the SRP functional predicts an activation barrier that is too low for the dissociation on the least coordinated kink atom, which is the site of the lowest energy transition state and where most of the dissociation occurs in the calculations.