摘要
近年来,Ga-ZSM-5型分子筛的合成与催化性能已有报道,但对Ga是否位于ZSM-5型沸石晶格中这一重要问题则显得证据不足。由于以往的合成均在NaOH等碱性介质中进行,重复性和产品的结晶度不能令人满意。本文报道在弱酸性介质中,NH<sub>4</sub>F存在下,Ga-ZSM-5型分子筛的合成。这种新的合成途径,克服了在碱性介质中合成的缺点。用多种手段研究了Ga-ZSM-5型分子筛结构与性能的关系,为Ga对ZSM-5沸石骨架的同晶取代提供了充分的证据。
Ga-ZSM-5 zeolite was synthesized by hydrothermal crystallization at 150--200℃
from a mixture countaining NH_4F and tetrapropylammonium bromide as template at
pH 5--7. NH_4-form precursors were obtained and converted to H-form Ga-ZSM-5 after
calcination. Ga-ZSM-5 zeolite was characterized by means of XRD, SEM and electron
microprobe analysis, IR, XPS and DTA, which showed that the gallium atoms were
situated in the zeolite framework.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1989年第5期476-480,共5页
Acta Chimica Sinica