Enhanced hydrogen separation performance of Linde Type-A zeolite molecular sieving membrane by cesium ion exchange

Selective separation of gaseous hydrogen from a mixed gas by zeolite molecular sieving membrane have advantages in continuous long-term industrial reprocessing due to their excellent thermal stability and chemical inertness. Herein, we report the synthesis of Linde Type A (LTA) zeolite molecular sieving membranes with considerably enhanced hydrogen separation performance via ion exchange with cesium cations. Because the sodium ions in Na-LTA framework replaced by cesium ions make the pore size narrower, the cation-exchanged membranes show large increase in hydrogen selective separation performance. The separation factors of Cs-LTA membrane of H2 with CO2, CH4 and C3H8 are 8, 23.4 and 176.8 respectively, exceeding 5.9, 3.3, and 128.5 for the original Na-LTA membrane. The results indicate that the Cs-LTA membrane holds great potential for application in H2 purification.