Two-dimensional hydrogen hydrates: structure and stability

Abstract

The structure and stability of two-dimensional hydrogen hydrate were investigated in this work using density functional theory. The results are in line with expectations that the occupied cages are more stable after their confinement between two parallel hydrophobic sheets. The four two-dimensional hydrogen hydrate crystals – BLHH-I, BLHH-II, BLHH-III and BLHH-IV – that we predicted were much more stable in a restricted environment than in a free environment, even close to or exceeding conventional hydrogen hydrates. Besides, we found that the stability of two-dimensional hydrates is inversely related to the increase in temperature. Our work highlights that two-dimensional hydrates provide a new research idea in the field of hydrogen storage.