Effect of Subsurface Oxygen on Selective Catalytic Reduction of NO by H2 on Pt(100): A First-Principles Study

详细信息    查看全文

• 作者：Li-yuan Huai ; Hui Wang ; Chao-zheng He ; Hong Wen ; Wen-cai Yi ; Jing-yao Liu
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：November 5, 2015
• 年：2015
• 卷：119
• 期：44
• 页码：24819-24826
• 全文大小：469K
• ISSN：1932-7455

文摘

The mechanisms of NO reduction by H₂ on the Pt(100) surface and the surface modified with subsurface oxygen atoms (Md-Pt(100)) are studied by first-principles calculations. Similar catalytic activity toward NO dissociation is found on both surfaces with barriers of 0.86 and 0.96 eV, respectively. The pathway of N + N 鈫?N₂ rather than NO + N 鈫?N₂ + O is the N₂ formation pathway on the Pt(100) surface, while these two pathways are competitive on the Md-Pt(100) surface. The NH₃ formation is almost negligible, and reductant hydrogen can effectively remove the surface oxygen on both surfaces. The microkinetic analysis further confirms that, compared to the high selectivity toward N₂O (almost 100% at 300鈥?00 K) on the clean surface, higher N₂ low-temperature selectivity (larger than 90%) is achieved on the Md-Pt(100) surface under lower pressure. The present study shows that subsurface oxygen has an enhanced effect for improving the N₂ selectivity of NO reduction on Pt catalysts.