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在弱酸性介质中,用四丙基溴化铵、氟化铵合成了B-ZSM-5型分子筛。由于晶化过程中无碱金属氢氧化物等强碱参与,B-ZSM-5型分子筛原粉为铵型,灼烧除掉NH_3及有机模板剂后,直接转化为氢型,吸附吡啶后IR谱中有B酸和L酸中心存在。扫描电镜分析表明,B-ZSM-5分子筛晶体生长完美,晶体形貌随硼含量不同呈规律性变化。X射线衍射、红外光谱、X射线光电子能谱、差热分析等结果表明,硼原子位于ZSM-5分子筛骨架中。
B-ZSM-5 molecular sieves were synthesized from tetrabutylammonium bromide and ammonium fluoride in weakly acidic medium. Due to the alkali alkali hydroxide and other alkali involved in the crystallization process, the original powder of B-ZSM-5 molecular sieve is ammonium type, after burning to remove NH 3 and organic templating agent, it is directly converted into hydrogen form, after adsorption pyridine There are B acid and L acid center in the spectrum. Scanning electron microscopy analysis showed that the crystal growth of B-ZSM-5 molecular sieve was perfect and the morphology of the crystal changed regularly with the content of boron. X-ray diffraction, infrared spectra, X-ray photoelectron spectroscopy, differential thermal analysis and other results show that boron atoms are located in the framework of the ZSM-5 molecular sieve.