Copper-based coordination polymers from thiophene and furan dicarboxylates with high isosteric heats of hydrogen adsorption

Abstract

Self-assembled Cu-based coordination polymers derived from thiophene-2,5-dicarboxylic acid (Cu-TDC) and furan-2,5-dicarboxylic acid (Cu-FDC) were synthesized via a solvothermal method and their H2 adsorption behaviour was investigated and contrasted with isophthalic acid (Cu-m-BDC) and terephthalic acid (Cu-BDC) derivatives. Both heterocyclic-based coordination polymers exhibit low surface areas (<300 m2 g -1) upon activation but unusually high isosteric heats of hydrogen adsorption (7.5-9.2 kJ mol-1). Hydrogen uptake values of 0.64-0.75 wt% (77 K and 1 bar) were recorded and these high uptake values are attributed to the optimal pore size (5.4-8 Å) and the polarizability of the 5-membered heterocycles.