A new MOF-505@GO composite with high selectivity for CO2/CH4 and CO2/N-2 separation

作者：Chen, Yongwei; Lv, Daofei; Wu, Junliang; Xiao, Jing; Xi, Hongxia; Xia, Qibin^*; Li, Zhong

来源：Chemical Engineering Journal, 2017, 308: 1065-1072.

DOI：10.1016/j.cej.2016.09.138

• Metal-organic framework
• Graphite oxide
• MOF-505@GO composites
• CO2 capture
• Adsorption selectivity

Novel MOF-505@GO composites comprised of a copper-based metal-organic framework and graphite oxide (GO) were synthesized by a solvothermal method for effective separation of CO2/CH4 and CO2/N-2, which are challenging chemical separations in industry. The composites were characterized by various techniques including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and porosity measurement through nitrogen adsorption at cryogenic temperature. Single component adsorption isotherm measurements of CO2, CH4 and N-2 were performed at different temperatures. The selectivities of CO2/CH4 and CO2/N-2 were estimated on the basis of ideal adsorbed solution theory (IAST). MOF505@GO composites showed higher porosity and enhanced CO2 adsorption compared to its parent compound MOF-505. MOF-505@5G0 exhibited the highest CO2 uptake of 3.94 mmol/g at 298 K and 100 kPa, having an increase of 37.3% in comparison with the parent MOF-505. The significant improvement of CO2 uptakes could be attributed to not only new micropores and unsaturated metal sites formed in the MOF505@GO, but also enhanced surface dispersive forces of the composites. The experimental adsorption isotherms of CO2, CH4 and N-2 were well fitted with dual site Langmuir-Freundlich (DSLF) model. The CO2/CH4 and CO2/N-2 adsorption selectivities were up to 8.6 and 37.2 at 298 K and 100 kPa, respectively, predicted by LAST. More strikingly, the composites showed excellent moisture stability, which was confirmed by PXRD analysis. These superior performances suggested that the MOF-505@GO composites are promising candidates for industrial CO2 capture.

• 出版日期2017-1-15
• 单位华南理工大学