High Pore Volume Hyper-Cross-Linked Polymers via Mixed-Solvent Knitting: A Route to Superior Hierarchical Porosity for Methane Storage and Delivery

Delving into effective polymerization systems to maximize the porosity of hyper-cross-linked polymers (HCPs) is highly favorable for simultaneously improving their high-pressure methane storage and delivery capacities. In the present work, a mixed-solvent knitting strategy was introduced to construct hierarchical polymer architectures at room temperature using dichloromethane (DCM) and dichloroethane (DCE) as dual external cross-linkers. A strong correlation exists between the textural properties of these polymers and their structural expanding/shrinking variations, showing a smooth transition from a highly microporous network to a hierarchical porous framework. Especially, HCP-MS-3 knitted by the mixed solvents of 1:1 volume ratio of DCM to DCE has an impressive high pore volume of 2.72 cm3 g–1, surpassing almost all previously reported HCPs, which not only exhibits an excellent gravimetric methane storage capacity up to 0.429 g g–1 at 273 K but also shows an effective methane delivery rate of nearly 90% from 5 to 100 bar. This simple and efficient mixed-solvent knitting strategy contributes a promising approach for the rational design of highly porous HCPs as low-cost and high-capacity methane adsorbents, which is highly desired for practical methane storage applications.