PKU-2: An intrinsically microporous aluminoborate with the potential in selective gas separation of CO2/CH4 and C2H2/C2H4

Abstract

Abstract Selective gas adsorption and separation were intensively investigated for porous materials like metal-organic frameworks (MOFs) and Zeolites. In this study, an intrinsically microporous aluminoborate, PKU-2, with an extra-large one dimensional channel (~9.6 A) was discovered for the first time to exhibit selective CO2 and C2H2 adsorption over CH4 and C2H4, respectively. Incorporation of Cr3+ and Fe3+ ions into the framework could effectively enlarge the specific surface area in comparison with the pristine PKU-2, which is accompanied with a significant enhancement of gas adsorption capacities for CO2 and C2H2 to 3.9 and 2.86 mmol/g, respectively, for Fe-PKU-2, and a slight decrease of gas separation selectivities. The high gas adsorption capacities and selectivities together with their high thermal stability imply their potential practice applications for environment and energy-relevant gas adsorption and separation.