Molecular insights into CH4/H2O transport and hydrate formation in hydrophobic metal-organic frameworks ZIF-8: Implication for CH4 storage by adsorption-hydration hybrid method

•Wettability and distribution of H2O on ZIF-8 was studied at the molecular level.•Mechanism of hydrate formation with competitive adsorption in ZIF-8 was revealed.•Hydrate nucleation preferentially occurs in central layer away from ZIF-8 surface.•Adsorption drives CH4 /H2O transport to promote nucleation of hydrate and bubbles.•Flat bubbles enhance diffusion to slow hydrate growth due to ZIF-8 physisorption.