2D Zeolite-Based Thin Film Nanocomposite Membranes for Efficient CO₂ Separation

Abstract

In this work, thin film nanocomposite (TFN) membranes based on 2D MFI zeolite nanosheets with a thickness of ∼40 nm and Pebax 2533 were fabricated via an in situ coating procedure. The 2D zeolite content in the MMMs, as well as the membrane coating solution concentration, was systematically investigated. Results show that by adding 5 wt % 2D MFI zeolite into Pebax 2533, the CO2 permeability of the MMMs can be promoted to 401.8 Barrer with only moderate reduction in CO2/N2 and CO2/CH4 selectivity. Subsequently, it is found that the coating concentration also plays critical role in CO2 separation performances, under optimized conditions, a CO2 permeance of 170 GPU coupled with CO2/N2 and CO2/CH4 selectivity of 18.48 and 8.06 were documented. In addition, the obtained membrane exhibited reasonable long-term stability over 70 h tests. The MMMs and TFN membranes were also thoroughly characterized by SEM, TGA, FTIR, and XRD techniques.