A comparative study in structure and reactivity of ＂FeOx-on-Pt＂ and ＂NiOx-on-Pt＂ catalysts

• Published in: Science China. Chemistry 2015-01, Vol.58 (1), p.162-168
• Main Authors: Mu, Rentao, Fu, Qiang, Guo, Xiaoguang, Xu, Xuejun, Tan, Dali, Bao, Xinhe
• Format: Article
• Language: English
• Subjects: Carbon monoxide; Catalysts; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Comparative studies; CO氧化; Metal surfaces; Noble metals; Oxidation; Substrates; Surface stability; Surface structure; Valence; 氧化反应; 氧化气氛; 纳米结构; 结构稳定; 表面氧化物; 还原反应; 铂催化剂
• ISSN: 1674-7291; 1869-1870
• DOI: 10.1007/s11426-014-5266-9

Oxide nanostructures grown on noble metal surfaces are often highly active in many reactions, in which the oxide/metal interfaces play an important role. In the present work, we studied the surface structures of FeOx-on-Pt and NiOx-on-Pt catalysts and their activity to CO oxidation reactions using both model catalysts and supported nanocatalysts. Although the active FeO1-x structure is stabilized on the Pt surface in a reductive reaction atmosphere, it is prone to change to an FeO2-x structure in oxidative reaction gases and becomes deactivated. In contrast, a NiO1-x surface structure supported on Pt is stable in both reductive and oxidative CO oxidation atmospheres. Consequently, CO oxidation over the NiO1-x-on-Pt catalyst is further enhanced in the CO oxidation atmosphere with an excess of O2. The present results demonstrate that the stability of the active oxide surface phases depends on the stabilization effect of the substrate surface and is also related to whether the oxide exhibits a variable oxidation state.