Helium Recovery by a Cu-BTC Metal-Organic-Framework Membrane

Highly diverse structures and pore sizes make metal organic frameworks (MPFs) good candidates for the fabrication of gas separation membranes. The synthesis of continuous MOF membranes still remains a challenge. In this work, an integrated Cu-BTC membrane was successfully prepared on the novel potassium hexatitanate support for the first time by in situ solvothermal growth. This kind of support was found to be more suitable for the growth of Cu2+-containing MOF membranes than other traditional supports, such as a porous alumina support. The permeation results of Cu-ETC membranes obtained in this work show moderate separation selectivities of helium over other small gas molecules, including CO2, N-2, and CH4. Compared to other MOF membranes, the Cu-BTC membrane exhibits higher ideal selectivity for helium under the condition of similar helium perrneance, while it has higher helium permeance with similar ideal selectivity.