Preferential adsorption of ortho-H2 with respect to para-H2 on the amorphous ice surface
Preferential adsorption of ortho-H2 with respect to para-H2 on the amorphous ice surface
复制标题
无定形冰表面上邻位氢气相对于对位氢气的优先吸附
DOI：
10.1063/1.465026
复制
发表时间：
1993
影响因子：
4.4
通讯作者：
J. Devlin
中科院分区：
文献类型：
--
作者：
V. Buch;J. Devlin
研究表明，在12K下，邻位氢气相对于对位氢气在无定形冰表面的优先吸附。实验部分着重研究了邻位氢气和对位氢气吸附的傅里叶变换红外吸收带和悬挂的外向键的时间依赖性。在新形成的吸附覆盖层的光谱中(在邻位到对位驰豫发生之前)，只有邻位-H_2红外光谱带可见，表明初始的对位-H_2含量小于10%。在计算部分，氢的吸附被模拟在无定形团簇(H2O)450上。计算研究包括表面孤立氢态的扩散蒙特卡罗模拟和吸附覆盖层的路径积分蒙特卡罗模拟。在巨正则系综下进行的路径积分蒙特卡罗模拟中，近似考虑了核的对称性效应。计算得到吸附层中对氢的百分含量为7%，...
This study demonstrates preferential adsorption of ortho‐H2 with respect to para‐H2 on the surface of amorphous ice exposed to normal H2 at 12 K. The experimental part of the study focuses on the time dependence of Fourier‐transform infrared bands of ortho‐H2 and para‐H2 adsorbate and of dangling‐OD bonds. In the spectrum of the newly formed adsorbate overlayer (before the ortho‐to‐para relaxation takes place) only the ortho‐H2 IR band is visible, identifying the initial para‐H2 content as less than 10%. In the computational part, H2 adsorption is modeled on an amorphous cluster (H2O)450. The computational study consists of the diffusion Monte Carlo investigation of isolated H2 states on the surface, and of path integral Monte Carlo simulation of the adsorbate overlayer. Nuclear symmetry effects are incorporated approximately in the path integral Monte Carlo simulation, which is carried out in the framework of the grand canonical ensemble. The calculated percentage of para‐H2 in the adsorbate layer is 7%,...