Post-synthetic metalation of porous framework materials for achieving high natural gas storage and working capacity: A GCMC simulation study

For the use of natural gas in automobiles, an adsorbent with high CH4 storage capacity and working capacity is desired. In this work, the effects of post-synthetic metalation on CH4 storage capacity and working capacity were investigated. Specially, the adsorption properties of CH4 in PAFs containing metal cations were calculated by GCMC simulations. The results indicated that the total volumetric uptake amounts and working capacity of CH4 were significantly enhanced by post-synthetic metalation. The incorporation of all studied metal cations into PAF-302 and Li, Mg, Ca, Co metal cations into PAF-303 can enhance the CH4 volumetric uptake amounts to exceed the 2012 DOE volumetric target (263 cm3(STP)/cm3). Furthermore, the working capacity in metal (except Mg, Ca, Ti and Co) functionalized PAF-302 was similar to that of MOFs with the highest measured volumetric methane working capacity reported so far. Specially, the working capacity in K and Cu functionalized PAF-302 was 211 cm3(STP)/cm3, which represents the reported highest CH4 working capacity to date.