Ionothermal synthesis of LTA-type aluminophosphate molecular sieve membranes with gas separation performance

摘要

LTA-type aluminophosphate molecular sieve membranes with gas separation performance were ionothermally synthesized by using delta-alumina substrates as both the supports and the aluminum sources. The effects of the synthesis parameters, such as the concentrations of H3PO4, TAMOH, and HF, and the detailed formation process of the membrane were thoroughly investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Furthermore, the subsequent membrane syntheses by using recycled mother liquids were also studied. The results demonstrated that continuous and compact LTA molecular sieve membranes can be prepared over a relatively wide range of the synthesis composition. The membranes prepared with fresh and recycled mother liquids exhibit the same crystallinity, morphology and the gas separation performance. Typically, for single-component gases at 293 K, the ideal separation factors of H-2/CO2, H-2/O-2, H-2/N-2, and H-2/CH4, are 10.9, 8.1, 6.8, and 4.8, respectively, which suggests the good gas separation performance of the membranes. (C) 2016 Elsevier Inc. All rights reserved.