A comparative study in structure and reactivity of “FeO_x-on-Pt” and “NiO_x-on-Pt” catalysts

• 作 者: Rentao Mu Qiang Fu Xiaoguang Guo Xuejun Xu Dali Tan Xinhe Bao
• 机 构: State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics, the Chinese Academy of Scien
• 出 处: Science China(Chemistry)
• 发表日期: 2015年01期
• 关键词: reactivity gases reductive stabilization prone oxidative Figure noble excess oxi

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 Fe Ox-on-Pt and Ni Ox-on-Pt catalysts and their activity to CO oxidation reactions using both model catalysts and supported nanocatalysts.Although the active Fe O1x structure is stabilized on the Pt surface in a reductive reaction atmosphere,it is prone to change to an Fe O2x structure in oxidative reaction gases and becomes deactivated.In contrast,a Ni O1x surface structure supported on Pt is stable in both reductive and oxidative CO oxidation atmospheres.Consequently,CO oxidation over the Ni O1x-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.

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 Fe Ox-on-Pt and Ni Ox-on- Pt catalysts and their activity to CO oxidation reactions using both model catalysts and supported nanocatalysts. Although the active Fe O1x structure is stabilized on the Pt surface in a reductive reaction atmosphere, it is prone to change to an Fe O2x structure in oxidative reaction gases and becomes deactivated. In contrast, a Ni O1x surface structure supported on Pt is stable in both reductive and oxidative CO oxidation atmospheres. Reconstructive, CO oxidation over the Ni O1x-on-Pt catalyst is further enhanced in the CO oxidation atmosphere with an excess of O2. This 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 va riable oxidation state.