Efficient purification of CH4 from ternary mixtures by a microporous heterometal-organic framework

Purification of methane (CH4) from multi-component mixtures containing acetylene (C2H2) and carbon dioxide (CO2) is a meaningful but challenging task. We herein reported a heterometal-organic framework, CuIn(ina)4, with microporous channels, which exhibits specific recognition of C2H2 and CO2 through suitable ultramicropores and surface environments. The results of experiments indicate that the title MOF shows high C2H2/CH4 selectivity (20.2) and CO2/CH4 selectivity (5.3). Column breakthrough experiments and theoretical calculations further demonstrate that CuIn(ina)4 can efficiently separate CH4 from ternary mixtures.