XPS study of as-prepared and reduced molybdenum oxides
XPS study of as-prepared and reduced molybdenum oxides
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DOI：
10.1016/0169-4332(95)00317-7
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发表时间：
1996-02-01
影响因子：
6.7
通讯作者：
Thompson, LT
中科院分区：
文献类型：
--
作者：
Choi, JG;Thompson, LT
利用X射线光电子能谱（XPS）研究了Mo氧化物（MoO 2和MoO 3）的表面性质。所制备的MoO 3在232.5和235.6 eV处显示出两条分辨良好的谱线，分别归属于Mo的3d（5/2），3d（3/2）自旋轨道分量。在样品用H-2在673 K下还原3 h后，表面上存在的MoO 3的76%转化为MoO 2。MoO 2的氢还原在228.7 +/- 0.2 eV的结合能处产生新的状态（Mo-δ +，0 <δ < 4）。我们基于Mo-0、Mo 4+、Mo 5+和Mo 6+的结合能分配将这个新状态分配给Mo 3+。Mo-δ +态的浓度随着还原时间的增加而增加，并且这种状态被认为含有氢，这可能是脱硫和脱氮反应的必要条件。
The surface properties of Mo oxides (MoO2 and MoO3) were investigated using X-ray photoelectron spectroscopy (XPS). As-prepared MoO3 showed two well resolved spectral lines at 232.5 and 235.6 eV, which were assigned to the Mo 3d(5/2), 3d(3/2) spin-orbit components, respectively. After the sample was reduced with H-2 at 673 K for 3 h, 76% of the MoO3 present on the surface was transformed to MoO2. Hydrogen reduction of MoO2 produced a new state (Mo-delta+, 0 < delta < 4) at a binding energy of 228.7 +/- 0.2 eV. We assigned this new state to Mo3+ based on our binding energy assignments for Mo-0, Mo4+, Mo5+, and Mo6+. The concentration of Mo-delta+ state increased with increasing reduction time and this state was suggested to contain hydrogen, which may be a necessary requisite for desulfurization and denitrogenation reactions.