Grand Canonical Monte Carlo Simulation Study on the Catenation Effect on Hydrogen Adsorption onto the Interpenetrating Metal−Organic Frameworks

Abstract

Among recently synthesized isoreticular metal-organic frameworks (IRMOFs), interpenetrating IRMOFs show high hydrogen adsorption capacities at low temperature and under ambient pressure. However, little is known about the molecular basis of their hydrogen binding properties. In this work, we performed grand canonical Monte Carlo (GCMC) simulations to investigate the effect of catenation on the interactions between hydrogen molecules and IRMOFs. We identified the adsorption sites and analyzed the adsorption energy distributions. The simulation results show that the small pores generated by catenation can play a role to confine the hydrogen molecules more densely, so that the capacity of the interpenetrating IRMOFs could be higher than that of the non-interpenetrating IRMOFs.

Recent advances on simulation and theory of hydrogen storage in metal–organic frameworks and covalent organic frameworks

“…From the two simulational works, 77,78 we can conclude that catenation is helpful for H 2 uptake in MOFs at 77 K and low pressures, but it could not be at room temperature. Fig.…”

“…The theoretical study on H 2 uptake in interpenetrated MOFs (IRMOF-9, -11, and -13) was first reported by Jung et al 77 using GCMC simulations at 77 K. The simulation shows that the small pores generated by the catenation play a role in confining the H 2 molecules more densely, indicating 77 they showed that at low pressures catenation is clearly beneficial for H 2 uptake, but at high pressures non-catenated MOFs exhibit higher H 2 uptake than their catenated MOFs. Their simulation for 298 K showed that in a gravimetric H 2 uptake unit the loading for the catenated structures is approximately one half that of the non-catenated structures, while in a volumetric unit a similar H 2 uptake amount is shown for catenated and non-catenated MOFs.…”

Progress on first-principles-based materials design for hydrogen storage

“…The governing thermodynamics associated with the gas uptake by MOFs is derived from the physisorption of gas molecules onto a chemically inert MOF surfaces. The polarity of a building unit and the appropriate spatial separation between the organic units can partially increase the binding strength of hydrogen molecules to some degree (24). However, these binding strengths still fall in the regime of physisorption and are on the order of several kJ/mol (a few tens of meV).…”

Molecular Simulation Study of CH4/H2 Mixture Separations Using Metal Organic Framework Membranes and Composites

“…37,[54][55][56] The Nosé-Hoover thermostat was used in NVT (canonical ensemble) MD simulations. 57 For the single component corrected (self) diffusivities, 20 (10) independent MD simulations were performed because using a large number of independent trajectories is vital to accurately compute the corrected diffusivities. Mixture self-diffusivities were computed at different adsorbed compositions of CH 4 :H 2 mixtures of 75:25, 50:50, and 25:75 in addition to an adsorbed phase composition of ∼98% CH 4 which corresponds to an equimolar bulk phase.…”

“…8 An accurate description of mixture adsorption and diffusion is crucial in many applications that are envisioned for MOFs such as membranes and adsorption-based separations. Adsorption of single component gases in MOFs has been examined in a large number of experiments and molecular simulations, [9][10][11][12][13][14][15][16][17][18][19][20] whereas less information is available about the properties of adsorbed gas mixtures in MOFs. [21][22][23][24][25][26][27][28][29] This situation is more striking when the transport of gases in MOFs is considered.…”