Promoting effect of CeO2 in combustion synthesized Pt/CeO2 catalyst for CO oxidation
Promoting effect of CeO2 in combustion synthesized Pt/CeO2 catalyst for CO oxidation
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DOI：
10.1021/jp022132f
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发表时间：
2003-06-26
影响因子：
3.3
通讯作者：
Arena, F
中科院分区：
文献类型：
--
作者：
Bera, P;Gayen, A;Arena, F
与Pt金属颗粒相比，通过溶液燃烧法制备的1%Pt/CeO2催化剂对O-2氧化CO表现出更高的催化活性。在 -25 摄氏度下，每个 Pt 至少吸收 6 个氢原子。通过 X 射线衍射 (XRD)、透射电子显微镜 (TEM)、X 射线光电子能谱 (XPS) 和傅里叶变换红外 (FTIR) 光谱研究了 1% Pt/CeO2 催化剂的结构。 Rietveld精修表明，Pt离子以Ce1-xPtxO2-δ固溶体的形式结合到CeO2基体中。与纯 CeO2 相比，1% Pt/CeO2 中的氧含量有所下降。 TEM 研究表明，Pt 以原子或离子形式分散，只有少量以 Pt 金属颗粒形式分散。 XPS 中的 Pt(4f) 核心能级区域表明 Pt 主要以 pt(2+) 离子态存在于 CeO2 表面。 1% Pt/CeO2 的 FTIR 显示在 2082 cm(-1) 处有一个强烈吸附的 CO 峰，对应于氧化的 Pt。这些结构研究表明，催化剂中的 Pt 离子以 Ce1-xPtxO2-delta 形式取代了 Cell 离子，产生了氧化物离子空位，从而产生了强烈的 pt(2+)-CeO2 相互作用，从而实现了更高的催化活性。
A 1% Pt/CeO2 catalyst prepared by the solution combustion method shows a higher catalytic activity for CO oxidation by O-2 compared to Pt metal particles. At least six hydrogen atoms are taken up per Pt at -25 degreesC. The structure of 1% Pt/CeO2 catalyst has been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. Rietveld refinement shows that Pt ions are incorporated into the CeO2 matrix in the form of Ce1-xPtxO2-delta solid solution. A decrease in oxygen content in 1% Pt/CeO2 is seen in relation to pure CeO2. TEM studies show that Pt is dispersed as atoms or ions and only a small amount as Pt metal particles. The Pt(4f) core level region in XPS shows that Pt is present mostly in the pt(2+) ionic state on CeO2 surface. FTIR of 1% Pt/CeO2 shows a strongly adsorbed CO peak at 2082 cm(-1) corresponding to oxidized Pt. These structural studies show that Pt ions in the catalyst are substituted for Cell ions in the form of Ce1-xPtxO2-delta, creating oxide ion vacancies leading to a strong pt(2+)-CeO2 interaction that is responsible for higher catalytic activity.