He Y B, Knapp M, Lundgren E, Over H
Department of Physical Chemistry, Justus-Liebig University, Heinrich-Buff-Ring, D-35392 Giessen, Germany.
J Phys Chem B. 2005 Nov 24;109(46):21825-30. doi: 10.1021/jp0538520.
With surface X-ray diffraction (SXRD) using a high-pressure reaction chamber we investigated in-situ the oxidation of the Ru(0001) model catalyst under various reaction conditions, starting from a strongly oxidizing environment to reaction conditions typical for CO oxidation. With a mixture of O(2) and CO (stoichiometry, 2:1) the partial pressure of oxygen has to be increased to 20 mbar to form the catalytically active RuO(2)(110) oxide film, while in pure oxygen environment a pressure of 10(-5) mbar is already sufficient to oxidize the Ru(0001) surface. For preparation temperatures in the range of 550-630 K a self-limiting RuO(2)(110) film is produced with a thickness of 1.6 nm. The RuO(2)(110) film grows self-acceleratedly after an induction period. The RuO(2) films on Ru(0001) can readily be reduced by H(2) and CO exposures at 415 K, without an induction period.
利用配备高压反应腔的表面X射线衍射（SXRD）技术，我们在各种反应条件下对Ru(0001)模型催化剂的氧化过程进行了原位研究，反应条件从强氧化环境到典型的CO氧化反应条件。在O₂和CO的混合物（化学计量比为2:1）中，氧气的分压必须增加到20毫巴才能形成具有催化活性的RuO₂(110)氧化膜，而在纯氧环境中，10⁻⁵毫巴的压力就足以氧化Ru(0001)表面。对于550 - 630 K范围内的制备温度，会生成厚度为1.6纳米的自限性RuO₂(110)膜。RuO₂(110)膜在经过诱导期后会自加速生长。Ru(0001)上的RuO₂膜在415 K下通过暴露于H₂和CO可很容易地被还原，且无诱导期。
