CO(2) separation using composites consisting of 1-butyl-3-methylimidazolium tetrafluoroborate/CdO/1-aminopyridinium iodide

1-Aminopyridinium iodide (iodine salt) was used in CO(2) separation composites consisting of CdO and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(+)BF(4)(−)). Using iodine salt, the separation performance was largely improved. The CO(2)/N(2) selectivity was 64.6 and the permeance of CO(2) gas was 22.6 GPU, which was about twice that of BMIM(+)BF(4)(−)/CdO composites without addition of iodine salt. These results were due to the both effect of iodine salt on the transport of the N(2) molecules by the cyclic ring compound and the promoting transport of CO(2) molecules by the amine groups. Moreover, the oxide layer on the surface of the CdO could enhance the CO(2) solubility, resulting in the enhancement of separation performance. The mechanical and chemical properties were measured using SEM, Raman, TGA and FT-IR. The cross-section of coated membranes was confirmed by SEM. The coordinative interactions of iodine salts with BMIM(+)BF(4)(−)/CdO composite were observed by Raman.