微波辅助二次生长法合成SAPO-34分子筛膜与关键影响因素

采用微波辅助二次生长法在α-Al₂O₃载体上合成了SAPO-34分子筛膜，并将其应用于CO₂/CH₄分离。通过扫描电镜、X射线衍射和傅里叶变换红外光谱等表征方法，系统考察了加热方式、晶种粒径、老化时间和晶化时间对SAPO-34分子筛膜表面形貌和结构的影响。实验结果表明，以0.4 μm分子筛作为晶种，在老化24 h，然后微波加热晶化4 h后可制备出厚度约为1.5 μm的致密、无缺陷SAPO-34分子筛膜，其平均CO₂/CH₄分离因子和CO₂渗透率分别达到81和6.6×10^-7 mol·m^-2·s^-1·Pa^-1，制备方法可靠，重复性高。

Synthesis of SAPO-34 membranes and critical influence factors in microwave-assisted secondary growth

SAPO-34 membranes for separation of CO₂/CH₄ gas mixture were fabricated on porous α-Al₂O₃ substrates by seeded growth under microwave irradiation. Effects of synthesis conditions, including heating mode, seed size, aging and synthesis time, on membrane morphology and structure were investigated in order to manufacture dense and thin SAPO-34 membranes. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize SAPO-34 membranes. 1.5 μm-thick defect-free SAPO-34 membrane could be obtained with high reproducibility at condition of 0.4 μm-sized seed, 24 h aging, and 4 h microwave heating. The new membrane demonstrated an average CO₂/CH₄ separation selectivity at 81 and high CO₂ permeability at 6.6×10^-7 mol·m^-2·s^-1·Pa^-1.