Copper(I)-Catalyzed Synthesis of Nanoporous Azo-Linked Polymers: Impact of Textural Properties on Gas Storage and Selective Carbon Dioxide Capture

A new facile method for synthesis of porous azo-linked polymers (ALPs) is reported. The synthesis of ALPs was accomplished by homocoupling of aniline-like building units in the presence of copper(1) bromide and pyridine. The resulting ALPs exhibit high surface areas (SA(BET) = 862-1235 m(2) g(-1)), high physiochemical stability, and considerable gas storage capacity especially at high-pressure settings. Under low pressure conditions, ALPs have remarkable CO2 uptake (up to 5.37 mmol g(-1) at 273 K and 1 bar), as well as moderate CO2/N-2 (29-43) and CO2/CH4 (6-8) selectivity. Low pressure gas uptake experiments were used to calculate the binding affinities. of small gas molecules and revealed that ALPs have high heats of adsorption for hydrogen (7.5-8 kJ mol(-1)), methane (18-21 kJ mol(-1)), and carbon dioxide (28-30 kJ mol(-1)). Under high pressure conditions, the best performing polymer, ALP-1, stores significant amounts of H-2 (24 g L-1, 77 K/70 bar), CH4 (67 g L-1, 298 K/70 bar), and CO2 (304 g L-1, 298 K/40 bar).