Dibromomethane Knitted Highly Porous Hyper-Cross-Linked Polymers for Efficient High-Pressure Methane Storage.

Hyper-cross-linked polymers (HCPs) with ultra-high porosity, superior physicochemical stability and excellent cost-effectiveness are attractive candidates for methane storage. However, the construction of HCPs with BET surface areas exceeding 3000 m 2 g -1 remains extremely challenging. In this work, a newly developed DBM-knitting method with a slow-knitting rate was employed to increase the crosslinking degree, in which dichloromethane (DCM) was replaced by dibromomethane (DBM) as both solvent and electrophilic cross-linker, resulting in highly porous and physicochemically stable HCPs. The BET surface areas of DBM-knitted SHCPs-Br are 44%-120% higher than that of DCM-knitted SHCPs-Cl using the same building blocks. Remarkably, SHCP-3-Br exhibits an unprecedentedly high porosity (S BET = 3120 m 2 g -1 ) among reported HCPs, and shows a competitive volumetric 5-100 bar working methane capacity of 191 cm 3 (STP) cm -3 at 273 K calculated by using real packing density, which outperforms sate-of-art MOFs at comparable condtions. This facile and versatile low-knitting-rate strategy enables effective improvement in the porosity of HCPs for porosity-desired applications. This article is protected by copyright. All rights reserved.