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发表时间：
1999
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通讯作者：
A. Auroux;A. Gervasini
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作者：
A. Auroux;A. Gervasini
采用XPS技术结合微量热法对载金属离子的沸石和硅铝样品的酸性质进行了表征。通过离子交换、浸渍和固态离子交换三种不同的方法将Co、Cu和Ni离子加载到ZSM-5和sio2 - al2o3（约1 mmol/g）上。两种基质离子交换制备的样品中金属离子的2 p 3/2 XPS谱带值较高，表明离子向载体基质发生了电荷转移。这使得金属相稳定为孤立的离子而不是氧化物团簇。进行氨吸附的微量热实验，以确定样品和相关基质上酸位的数量、强度（即吸附焓）和强度分布。表面吸附氨的n1s XPS谱线分解为两个组份峰，分别属于Bro nsted （BE平均值，402.2 eV）和Lewis （BE平均值，4000.4 eV）酸位。测定两个峰组分的相对强度，定量测定Bro nsted和Lewis酸位点浓度。结合吸附量热法和n1s吸附谱线的XPS光谱信息，确定了每个样品上Bro′nsted和Lewis酸位点的绝对数量。两种载体基质均为质子酸（ZSM-5和sio2 - al2o3分别占65%和60%的Bro′nsted酸位），从总酸位数和酸强度来看，ZSM-5的酸性大于sio2 - al2o3。沉积在两种基体上的金属离子的存在深刻地改变了Bro´nsted和Lewis位点的比例。观察到zsm -5基样品（含Co、Cu和Ni样品的Lewis位点分别为70%、85%和90%）和离子交换法制备的sio2 - al2o3基样品（含Co、Cu和Ni样品的Lewis位点分别为55%、60%和70%）的Lewis酸位点数量大幅增加。
The XPS technique in combination with microcalorimetry was used to picture the acid character of metal ion loaded zeolite and silica -alumina samples. Co, Cu, and Ni ions were loaded on ZSM-5 and SiO 2-Al2O3 (about 1 mmol/g) by three different procedures: ion exchange, impregnation, and solid-state ion-exchange. The samples prepared by ion exchange of the two matrixes presented high values of the 2 p 3/2 XPS bands of the metal ions, indicating the occurrence of charge transfer from the ions to the support matrix. This permitted the stabilization of the metal phases as isolated ions rather than as oxide clusters. Microcalorimetric experiments of ammonia adsorption were performed in order to determine the number, strength (i.e., adsorption enthalpy), and strength distribution of the acid sites on the samples and on the relevant matrixes. The N 1s XPS lines of ammonia adsorbed on the surfaces were decomposed into two component peaks, assigned to Bro ̈nsted (average value of BE, 402.2 eV) and Lewis (average value of BE, 400.4 eV) acid sites. The relative intensities of the two peak components were measured for the quantitative determination of Bro ̈nsted and Lewis acid site concentrations. Coupling the information from adsorption calorimetry and XPS spectroscopy of N 1s adsorbed lines, the absolute numbers of Bro ̈nsted and Lewis acid sites on each sample were determined. The two support matrixes were protonic acids (65 and 60% of Bro ̈nsted acid sites for ZSM-5 and SiO 2-Al2O3, respectively), and the acidity of ZSM-5 was greater than that of SiO 2-Al2O3 considering both the number of total acid sites and the acid strength. The presence of metal ions deposited on the two matrixes deeply changed the respective proportions of Bro ̈nsted and Lewis sites. A huge increase in the Lewis acid site population of the ZSM-5-based samples (70, 85, and 90% of Lewis sites for the samples containing Co, Cu, and Ni, respectively) and of the SiO 2-Al2O3-based samples prepared by ion exchange (55, 60, and 70% of Lewis sites for the samples containing Co, Cu, and Ni, respectively) was observed.