论文标题
H2在Cu上的激活解离（001）：量子隧穿的作用
Activated Dissociation of H2 on Cu(001): The Role of Quantum Tunneling
论文作者
论文摘要
理论上研究了H2分子在Cu（001）表面上的激活和解离。 H2在Cu上解离的激活屏障（001）通过第一原理计算确定高度〜0.59 eV。电子从底物Cu到H2的转移在激活，H-H键的破坏和CU-H键的形成中起关键作用。在键断裂的临界高度附近，确定了两个固定状态，分别对应于分子和解离状态。使用转移矩阵方法，我们能够研究沿最小能量途径（MEP）的量子隧道在解离过程中的作用，在室温下及以下是显着的。在给定的温度下，对H2的平移和振动动作的隧道贡献进行了量化以进行解离过程。在广泛的温度范围内，量子隧穿对解离的有效屏障和速率常数的影响被揭示。与热平衡和非平衡（分子束）条件相关的推导的能量参数与实验数据相当。在低温区域中，确定了从经典到量子状态的交叉。
The activation and dissociation of H2 molecules on Cu(001) surface is studied theoretically. The activation barrier for the dissociation of H2 on Cu(001) is determined by first-principles calculations to be ~ 0.59 eV in height. Electron transfer from the substrate Cu to H2 plays a key role in the activation, breaking of the H-H bond and the formation of the Cu-H bonds. At around the critical height of bond breaking, two stationary states are identified, which correspond respectively to the molecular and dissociative state. Using the transfer matrix method, we are able to study the role of quantum tunneling in the dissociation process along the minimum energy pathway (MEP), which is found to be significant at room temperature and below. At given temperatures, the tunneling contributions from the translational and vibrational motions of H2 are quantified for the dissociation process. Within a wide range of temperatures, the effects of quantum tunneling on the effective barriers of dissociation and the rate constants are revealed. The deduced energetic parameters associated with thermal equilibrium and non-equilibrium (molecular beam) conditions are comparable with experimental data. In the low-temperature region, crossover from classical to quantum regime is identified.
