A metalloporphyrinic compound with a high selectivity for N-2 and CO2 separation

Abstract

Using a hydrothermal reaction of SmCl3 center dot 6H(2)O, ZnBr2 and TPPS, a crystalline metalloporphyrinic compound (MPC), [SmZn(TPPS)H3O](n)center dot 2nH(2)O (1), was synthesized. The crystal structure of the MPC exhibits a condensed and robust 3-D porous open framework. We studied the adsorption and desorption isotherms for N-2, H-2 and CO2 conducted at 77 K and 273 K. They show different isotherms such as Type I, II and III isotherm behaviors. We found that low temperature is propitious for the title complex to adsorb more H-2, but less N-2. Compound 1 showed remarkably high selectivity for CO2-N-2 separation, and good thermal stability. The temperature dependent magnetic susceptibility shows an antiferromagnetic-like behavior for 1.