Ponce-Pérez R, Cocoletzi Gregorio H, Takeuchi Noboru
Benemérita Universidad Autónoma de Puebla, Instituto de Física, Apartado Postal J-48, C. P. 72570, Puebla, México.
Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Ensenada, Baja California, México.
J Mol Model. 2017 Nov 28;23(12):359. doi: 10.1007/s00894-017-3536-0.
Spin-polarized first-principles total-energy calculations have been performed to investigate the possible chain reaction of acetylene molecules mediated by hydrogen abstraction on hydrogenated hexagonal boron nitride monolayers. Calculations have been done within the periodic density functional theory (DFT), employing the PBE exchange correlation potential, with van der Waals corrections (vdW-DF). Reactions at two different sites have been considered: hydrogen vacancies on top of boron and on top of nitrogen atoms. As previously calculated, at the intermediate state of the reaction, when the acetylene molecule is attached to the surface, the adsorption energy is of the order of -0.82 eV and -0.20 eV (measured with respect to the energy of the non interacting molecule-substrate system) for adsorption on top of boron and nitrogen atoms, respectively. After the hydrogen abstraction takes place, the system gains additional energy, resulting in adsorption energies of -1.52 eV and -1.30 eV, respectively. These results suggest that the chain reaction is energetically favorable. The calculated minimum energy path (MEP) for hydrogen abstraction shows very small energy barriers of the order of 5 meV and 22 meV for the reaction on top of boron and nitrogen atoms, respectively. Finally, the density of states (DOS) evolution study helps to understand the chain reaction mechanism. Graphical abstract Acetylene chain reaction on hydrogenated boron nitride monolayers.
已进行自旋极化第一性原理全能量计算，以研究氢化六方氮化硼单层上氢提取介导的乙炔分子可能的链反应。计算是在周期性密度泛函理论（DFT）内进行的，采用PBE交换关联势，并进行了范德华修正（vdW-DF）。考虑了两个不同位点的反应：硼原子顶部和氮原子顶部的氢空位。如先前计算的那样，在反应的中间状态，当乙炔分子附着在表面时，对于吸附在硼原子和氮原子顶部，吸附能分别约为-0.82 eV和-0.20 eV（相对于非相互作用分子-底物系统的能量测量）。氢提取发生后，系统获得额外能量，导致吸附能分别为-1.52 eV和-1.30 eV。这些结果表明链反应在能量上是有利的。计算得到的氢提取的最小能量路径（MEP）显示，对于在硼原子和氮原子顶部的反应，能量垒非常小，分别约为5 meV和22 meV。最后，态密度（DOS）演化研究有助于理解链反应机理。图形摘要：氢化氮化硼单层上的乙炔链反应。
