Ultra-fast diffusion of hydrogen in a novel mesoporous N-doped carbon

Abstract

The diffusional behaviour of H 2 adsorbed in a novel mesoporous N-doped carbon material and on exfoliated graphite has been studied with quasi-elastic neutron scattering. While the activation energies for diffusion obtained for exfoliated graphite was in line with prior results, H 2 in the mesoporous carbon showed an exceptionally low diffusion barrier and behaved qualitatively like liquid hydrogen. Complementary results from neutron and X-ray diffraction as well as from isothermal nitrogen sorption studies provide a full characterisation of this novel mesoporous carbon.

Neutron spectroscopy study of the diffusivity of hydrogen in MoS2

“…9) following a DQ 2 law at low values of momentum transfer and reaching a plateau at high Q. 2 As was observed earlier, 46 diffusion models with a continuous distribution of jump lengths, like the Singwi-Sjölander 47…”

“…It was obtained by Graham et al 50 for a (111) surface of Pt by means of quasi-elastic helium atom scattering. We also add to the comparison the diffusion of hydrogen molecules on exfoliated graphite, studied by Bahn et al 46 with quasi-elastic neutron scattering. Exfoliated graphite has not shown any significant activity in the HER reaction 4 but its layered structure is similar to MoS 2 , hence it can be used as a reference non catalytic material.…”