Study on adsorption performance of conjugated microporous polymers for hydrogen and organic solvents: The role of pore volume

A series of homocoupled conjugated microporous polymers (HCMPs) were prepared by cross-coupling polymerization of 1,3,5-triethynylbenzene and 1,4-diethynylbenzene with various monomer molar ratios. Our results show that the molar ratio of monomers has a remarkable influence on the surface area, pore volume, and micropore volume of the as-synthesized HCMP samples. With the increase of molar ratio of 1,3,5-triethynylbenzene to 1,4-diethynylbenzene, the surface area and total pore volume increased while the micropore volume decreased for these HCMP samples. We also investigated the adsorption performance for hydrogen and organic solvents of these HCMP samples. Results obtained from experiments show that the increase of total pore volume (contributed from both mesopore and micropore) of HCMPs would lead to an increase in their adsorption abilities for organic solvents, while hydrogen sorption ability for HCMPs can only be improved by increasing their micropore volume, which may provide useful guidance for the rational design of novel HCMPs with different porosities as absorbent materials for oil/organic solvents or hydrogen storage systems.