Covalent organic framework nanoporous materials for high pressure gas storage

A method of storing gas, the method comprising:

• providing a recipient for receiving the gas;
• providing a porous gas storage material, the gas storage material comprising:
• a cross-linked polymeric framework;
• and
• a plurality of pores for gas sorption;
• wherein the cross-linked polymeric framework comprises aromatic ring-containing monomeric units comprising at least two aromatic rings selected from the group consisting of:
• and wherein the aromatic ring-containing monomeric units are linked by covalent cross-linking between aromatic rings;
• and
• loading the recipient with the gas;
• the recipient being designed to sustain a nominal maximum internal pressure P1 greater than atmospheric pressure;
• the porous gas storage material being disposed within said recipient;
• and
• loading the recipient with the gas to a pressure P2 equal to or lower than P1.