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

Abstract

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.