Diffusion of H-2 and D-2 Confined in Single-Walled Carbon Nanotubes: Quantum Dynamics and Confinement Effects

作者：Mondelo Martell Manel; Huarte Larranaga Fermin^*

来源：Journal of Physical Chemistry A, 2016, 120(33): 6501-6512.

DOI：10.1021/acs.jpca.6b00467

We present quantum dynamics calculations of the diffusion constant of H-2 and D-2 along a single-walled carbon nanotube at temperatures between 50 and 150 K. We calculate the respective diffusion rates in the low-pressure limit by adapting well-known approaches and methods from the chemical dynamics field using two different potential energy surfaces to model the C-H interaction. Our results predict a usual kinetic isotope effect, with H2 diffusing faster than D-2 in the higher temperature range but a reverse trend at temperatures below 50-70 K. These findings are consistent with experimental observation in similar systems and can be explained by the different effective size of both isotopes resulting from their different zero-point energy.

• 出版日期2016-8-25