Abstract:

MOF-505@GO composites with different ratios of MOF-505 to graphite oxide were synthesized by solvothermal method. They were characterized by powder X-ray diffractions(PXRD), scanning electron microscopy (SEM), Raman and porosity measurement through nitrogen adsorption. The isotherms of CH₄, C₂H₆ and C₃H₈ on the MOF-505@GO and MOF-505 were measured separately. Results showed that MOF-505@5GO had the largest pore volumes and BET surface area. The pore volumes and BET surface areas of MOF-505@GO increased as the GO content increased, when GO contents increased to 8%(mass) and 10%(mass), the opposite trend was observed in which the pore volumes and BET surface areas decreased. Accordingly, MOF-505@5GO exhibited the highest CH₄, C₂H₆ and C₃H₈ uptake of 0.88, 4.81 and 5.17 mmol·g^-1 at 298 K and 0.1 MPa, having an increase of 14.9%, 30.7% and 13.1%, respectively. Moreover, IAST-predicted C₂H₆/CH₄ selectivity of MOF-505@5GO was about 40.1 and C₃H₈/CH₄ selectivity was about 3056.1. It suggests that MOF-505@5GO is a promising candidate for the separation of C₂H₆/CH₄ and C₃H₈/CH₄.

Key words: MOF-505@GO, methane, ethane, propane, adsorption, binary mixture

摘要：

应用溶剂热法合成了不同氧化石墨烯（GO）负载量的MOF-505@GO复合材料，分别采用全自动表面积吸附仪、P-XRD、SEM和Raman对材料进行了性能表征，测定了CH₄、C₂H₆和C₃H₈在MOF-505@GO上的吸附等温线，并进行Langmuir-Freundlich方程拟合，依据IAST理论模型计算了C₂H₆/CH₄和C₃H₈/CH₄二元混合气在MOF-505@5GO上的吸附选择性。研究结果表明，随着GO负载量增大，MOF-505@GO复合材料的孔容及BET比表面积先增大后减小，当GO负载量为5%（质量）时，复合材料MOF-505@5GO的孔容及BET比表面积达到最大，当GO负载量进一步增大至8%（质量）和10%（质量）时，复合材料的孔容及BET比表面积逐渐降低。在0.1 MPa和298 K条件下，MOF-505@5GO对CH₄、C₂H₆和C₃H₈的吸附容量分别为0.88、4.81和5.17 mmol·g^-1，相比MOF-505分别提高了14.9%、30.7%和13.1%。MOF-505@5GO对C₂H₆/CH₄和C₃H₈/CH₄的吸附选择性分别为40.1和3056.1，其对C₂H₆/CH₄和C₃H₈/CH₄具有极高的吸附选择性。

关键词: MOF-505@GO, 甲烷, 乙烷, 丙烷, 吸附(作用), 二元混合物