Nitrogen-incorporated zeolites were prepared by subjecting HZSM-5 zeolite to APTES pre-treat and nitridation treatment with ammonia. The structure and framework nitride species of the silicon oxynitride zeolites were investigated by means of elemental analysis, nitrogen sorption measurements, XRD, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results indicated nitrogen-incorporated HZSM-5 zeolite still maintained good structure, and possessed high surface area and good crystallinity. In situ DRIFTS experiment confirmed that N atoms have been introduced into the framework by nitridation to form Si-NH2 ,Si-NH-Al and Si-NH2-Al species. It was suggested that organic amine produced active groups when in the nitridation process, these active groups along with ammonia took part in nitridation reaction to form nitrogenous species. The acid amount of the modified zeolite sharply decrease, while basic amount of that increase. This novel mothod greatly enhances nitrogen content.%以HZSM-5为原料,采用γ-氨丙基三乙氧基硅烷(APTES)改性与高温氨气掺氮的两步法制备了氮化HZSM-5分子筛.采用元素分析、N2吸附、X射线衍射、原位漫反射红外等技术对材料的结构性能进行了研究.结果表明,经APTES改性后的掺氮HZSM-5分子筛的晶型结构保持完整,且孔结构保持良好.原位漫反射红外实验表明,改性的掺氮分子筛存在不同的氮物种,氮原子取代或部分取代氧原子,以-NH2、-NH-的形式进入分子筛骨架,形成Si-NH2、Si-NH-Al以及Si-NH2-Al物种.由此,提出了相应的掺氮机理:高温焙烧的过程中,有机胺的分解产生活性位,与氨气一起参与氮化反应,生成了相应的氮物种.程序升温脱附实验表明改性后的分子筛的强酸位急剧减少,而碱量增加.这种两步制备法有效地促进了氮原子的掺杂并进入骨架.
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