Interactions of CO with Pt/ceria catalysts
Interactions of CO with Pt/ceria catalysts
复制标题
DOI：
10.1016/s0926-3373(99)00047-8
复制
发表时间：
1999-09-20
影响因子：
22.1
通讯作者：
Duprez, D
中科院分区：
文献类型：
--
作者：
Holmgren, A;Andersson, B;Duprez, D
通过储氧能力测定、CO和CO2同位素交换和FT-IR研究了CO与Pt/CeO 2催化剂之间的相互作用。还研究了Pt/氧化铝样品用于比较。作为氧化铈表面积和Pt-氧化铈接触的函数的存储和释放氧的能力进行了估计。发现来自Pt前体的氯的存在不会降低储氧能力。然而，FT-IR测量结果表明，氯阻碍了碳酸盐的形成，在CO暴露，这被发现是在预氧化的样品上的碳存储的主要形式。在强烈还原的样品上，发现随着还原度的增加，CO的还原程度也增加。CO和CO2同位素交换表明，这些分子在400 ℃下很容易与Pt/二氧化铈和二氧化铈交换它们的氧。还研究了在-78 ° C下的CO化学吸附作为测定金属分散的方法。在此温度下，在二氧化铈上的CO吸收被强烈抑制，特别是在无Cl样品上，但不完全受阻。(C)1999 Elsevier Science B. V.保留所有权利。
The interaction between CO and Pt/ceria catalysts was investigated by oxygen storage capacity measurements, CO and CO2 isotope exchange and FT-IR measurements. A Pt/alumina sample was also investigated for comparison. The capacity to store and release oxygen as a function of ceria surface-area and Pt-ceria contact was estimated. The presence of chlorine from the Pt pre-cursor was found not to decrease the oxygen storage capacity. However, FT-IR measurements showed that chlorine hindered the carbonate formation during CO exposure, which was found to be the main form of carbon storage on the pre-oxidized sample. On a strongly reduced sample, CO disproportionation was found to occur to an increasing extent with increasing degree of reduction. CO and CO2 isotope exchange showed that these molecules exchange their oxygen with Pt/ceria and ceria quite easily at 400 degrees C. CO chemisorption at -78 degrees C as a method to determine the metal dispersion was also investigated. At this temperature, the CO uptake on ceria was strongly suppressed, especially on the Cl-free sample, but not completely hindered. (C) 1999 Elsevier Science B.V. All rights reserved.