载体自转晶B-Al-MFI型沸石膜的原位合成与表征

In-situ Synthesis and Characterizations of B-Al-MFI-type Zeolite Membrane by Substrate Self-transformation

在乙胺和水混合蒸汽相中 ,首次通过载体自转晶 ,在多孔玻璃片表面原位合成了B Al MFI型沸石膜 FEAM分析表明 ,沸石膜的化学组成为w(B2 O3 ) =3.7% ,w(Al2 O3 ) =0 .5 5 % ,w(SiO2 ) =95 .2 5 % ,w(Na2 O) =0 .5 0 % X 射线衍射和扫描电镜观察证明 ,膜中沸石晶体的取向是随机的 晶体尺寸约为 15～ 2 5 μm ,单层晶体厚的膜约为 10～ 2 0 μm 在焙烧除去有机模板剂后的沸石膜上 ,O2 和N2 的透过性分别为 0 .0 95× 10 -8和0 .15× 10 -8mol/ (m2 ·s·Pa) 计算的O2 /N2 的理想选择性 (0 .6 3)明显低于诺森扩散的理想选择性值 (0 .94)和透过原载体的理想选择性值 (0 .91)

An B Al MFI type zeolite membrane was in situ synthesized on the surfaces of boron silicon porous glass disc by substrate self transformation in the vapor of ethylamine (EA) and H 2O.Surface microprobe analysis shows that the chemical composition of the membrane is w (B 2O 3)=3.70%, w (Al 2O 3)=0.55%, w (SiO 2)=95.25%, w (Na 2O)=0.50%.Both XRD and SEM show that the zeolite crystals on the surfaces of the porous glass disc are in random orientation.The crystal sizes in the membrane are in the range of ca .15 25 μm.The thicknesses of the membranes with the form of one crystal layer are ca .10 20 μm.The permeabilities of O 2 and N 2 are 0.095×10 -8 and 0.15 ×10 -8 mol/(m 2·s·Pa) on the calcined B Al MFI type zeolite membrane,respectively.The calculated ideal selectivity of O 2/N 2 (0.63) is obviously lower than that for Knudsen behaviour (0.94) and for the substrate (0.91).