Efficient adsorption separation of methane from C2–C3 hydrocarbons in a Co(II)-nodes metal–organic framework
Jie Zhang, Xing-Zhe Guo, Bing Lin, Guangzu Xiong, Hanshuang Wang, Min Zhang, Liwen Fan, Bingwen Li, Shui-Sheng Chen
Abstract
ABSTRACT Methane (CH 4 ) as a substitute for other mineral fuels plays a crucial role in reducing energy consumption and preventing environmental pollution . The present study employs a solvothermal method to fabricate a porous framework Co-metal–organic framework (Co-MOF) containing two distinct secondary building units (SBUs): an anionic [Co 2 (μ 2 -OH)(COO) 4 (H 2 O)] and a neutral [CoN 2 (COO) 2 ]. Notably, within the anionic SBUs, the coordinated water molecules induce the generation of divergent unsaturated Co(II) centers in the unidirectional porous channels, thereby creating open metal sites. The adsorption performance of Co-MOF towards pure component gases was systematically investigated. The results demonstrated that Co-MOF exhibits superior adsorption capacity for C 2 –C 3 hydrocarbons compared to CH 4 , which offers the potential for efficient adsorption and separation of CH 4 from C 2 –C 3 hydrocarbons. The gas selectivity separation ratios of Co-MOF for C 2 H 6 /CH 4 and C 3 H 8 /CH 4 were calculated using the ideal adsorbed solution theory method at 273/298 K and 0.1 MPa. The results revealed that Co-MOF achieved remarkable equilibrium separation selectivity for CH 4 and C 2 –C 3 hydrocarbon gases among non-modified MOFs , signifying the potential of the synthesized Co-MOF for efficient recovery and purification of CH 4 from C 2 –C 3 hydrocarbons. Breakthrough experiments further demonstrate the ability of Co-MOF to purify methane from C 2 –C 3 hydrocarbons in practical gas separation scenarios. Additionally, molecular simulation calculations further substantiate the propensity of anionic SBUs to interact with C 2 –C 3 hydrocarbon compounds. This study provides a novel paradigm for the development of porous MOF materials in the application of gas mixture separation.