碳酸盐的形成和分解在先前覆盖的原子氧Au(111) 上
Rotimi A Ojifinni1, Jinlong Gong, Nathan S Froemming
1University of Texas at Austin, Departments of Chemical Engineering and Chemistry, Center for Nano- and Molecular Science and Technology, and Texas Materials Institute, 1 University Station C0400, Austin, Texas 78712-0231
Journal of the American Chemical Society
|August 6, 2008
概括
这项研究揭示了碳酸盐的形成和反应在黄金表面使用氧气和标记的二氧化碳. 这些发现提升了我们对表面化学和催化物的理解.
科学领域:
- 表面科学是一门学科.
- 化学动力学 化学动力学
- 计算化学计算化学
背景情况:
- 黄金表面在催化过程中至关重要.
- 了解氧气和二氧化碳的相互作用是催化剂设计的关键.
- 原子氧在表面反应中起着重要作用.
研究的目的:
- 为了研究碳酸盐的形成和对原子氧的反应,先前覆盖了Au(111).
- 为了阐明二氧化碳与含氧黄金表面相互作用期间氧同位素交换的机制.
- 为了确定表面碳酸盐形成和分解的反应动力学和能量学.
主要方法:
- 使用同位素标记的二氧化碳 (C18O2) 进行温度调节溶解 (TPD) 的实验研究.
- 密度函数理论 (DFT) 计算以支持实验观测.
- 不同的表面温度 (77-400 K) 和初始氧气覆盖率 (0.18-2.1 ML).
主要成果:
- 观察到氧气混合 (16O18O的形成),表明碳酸盐的形成和分解.
- 表面碳酸盐的形成和分解发生在77-400 K之间.
- 估计的反应概率为~10(-4) 和激活能量为-0.15 ± 0.08 eV.
结论:
- 实验和计算结果证实了Au上的碳酸盐形成和反应途径.
- 氧同位素交换提供了表面碳酸盐中间体的直接证据.
- 该研究量化了反应动力学,提供了对黄金表面催化过程的见解.
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