沉积硝酸铝结合水热处理改性的HY型沸石羟基的变化  

CHANGES OF OH GROUPS IN HY(Al) ZEOLITE MODIFIED BY ALUMINUM NITRATE DEPOSITION TOGETHER WITH HYDROTHERMAL TREATMENT

作　　者：王奎[1] 康小洪[1] 钱婉华[1] 孙殿卿[1] 

机构地区：[1]石油化工科学研究院,北京100083

出　　处：《石油学报（石油加工）》2002年第4期23-26,共4页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：采用FT IR技术 ,以母体HY型分子筛为参照 ,研究了沉积硝酸铝结合高温水蒸气处理改性分子筛HY(Al)表面羟基的变化。结果表明 ,HY(Al)的羟基伸缩振动光谱与母体HY型分子筛明显不同。表现在 :(1)除 374 1cm-1谱峰表征的羟基 (—OH)外 ,总体羟基数目减少 ;(2 )低频—OH消失 ,同时在 35 72cm-1产生新谱峰 ;(3)非酸性羟基转化成为对吡啶敏感的酸性羟基。吡啶与羟基作用会在羟基振动区产生负的吸收峰 ,它们与吸附吡啶前的羟基谱峰有对应关系。由此推断 ,吸附吡啶前 35 72cm-1谱峰由 35 6 4和 35 85cm-1谱峰叠合形成 ;而 374 1cm-1谱峰则包含至少 374 5、 3738和 3715cm-13种羟基谱峰。The changes of OH groups in HY(Al) zeolite modified by aluminum nitrate deposition together with hydrothermal treatment, compared with parent HY zeolite, was studied by using FT-IR. It was found that FT-IR spectra of HY(Al) in hydroxyl stretching region, before or after pyridine adsorption followed by evacuation at 200°C or 350°C, were evidently different from parent HY in the following aspects: (a) total number of OH groups decreased, except OH characterized by 3741 cm-1 band; (b) (lf) OH band disappeared, and a new 3572 cm-1 band emerged; (c) nonacidic OH groups were transformed to acidic ON groups, which are sensitive to pyridine adsorption. The negative IR peaks resulted from the disappearance of the peaks when the OHs were bonded to pyridine. In accordance with the peak positions of OH groups before pyridine adsorption, it was believed that the superposition of 3564 cm-1 and 3585 cm-1 peaks generated 3572 cm-1 peak, and 3741 cm-1 peak included at lest three OH groups of 3745 cm-1, 3738 cm-1 and 3715 cm-1 peaks.

关 键 词：沉积硝酸铝 结合 水热处理 改性 HY型沸石 羟基 FT-IR光谱 

分 类 号：TQ424.25[化学工程]