Tailoring Mesoporous γ-Al2O3 Properties by Transition Metal Doping: A Combined Experimental and Computational Study

详细信息    查看全文

• 作者：Liangjie FuHuaming Yang ; Yuehua Hu ; Di Wu ; Alexandra Navrotsky
• 刊名：Chemistry of Materials
• 出版年：2017
• 出版时间：February 14, 2017
• 年：2017
• 卷：29
• 期：3
• 页码：1338-1349
• 全文大小：937K
• ISSN：1520-5002

文摘

Well crystallized gamma alumina (γ-Al₂O₃) with high thermal stability is as an important catalyst support. A series of first row transition metal (TM) doped aluminas with ordered mesoporous structures and homogeneous distribution of TM in the bulk structure has been synthesized by a one-pot method. The structures are studied by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM), while the electronic properties are explored by X-ray photoelectron spectroscopy (XPS), valence band XPS, and UV–vis spectra. To explore the influence of TM dopants on atomistic properties (bond length, charge state, band edge, and redox properties) of γ-Al₂O₃, the cation distribution of TM dopants is studied in detail by combining experiments and density functional theory (DFT) calculations. The cooperative effect of TM dopants and intrinsic defects in γ-Al₂O₃ induces a doping mechanism distinct from that in other spinel oxides; the concentration of Al vacancies (V_Al) decreases with increasing atomic number of the TM dopant as a result of charge compensation effects. Such variation could be used to tailor the properties and alter the reactivity of γ-Al₂O₃.