Comparative kinetic studies of CO$z.sbnd;O2 and CO$z.sbnd;NO reactions over single crystal and supported rhodium catalysts
Comparative kinetic studies of CO$z.sbnd;O2 and CO$z.sbnd;NO reactions over single crystal and supported rhodium catalysts
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DOI：
10.1016/0021-9517(86)90103-x
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发表时间：
1986-08
影响因子：
7.3
通讯作者：
S. Oh;G. Fisher;Joyce E. Carpenter;D. Goodman
中科院分区：
文献类型：
--
作者：
S. Oh;G. Fisher;Joyce E. Carpenter;D. Goodman
在实际反应物压力下，比较了单晶 Rh (111) 和氧化铝负载的 Rh 催化剂上 CO O 2 和 CO NO 反应的动力学。对于CO O 2 反应，两种Rh 催化剂测得的比速率和活化能之间非常一致。另一方面，CO NO 反应在单晶催化剂和负载型催化剂之间表现出截然不同的活化能和特定反应速率。这表明CONO反应动力学与COO 2 反应动力学不同，对催化剂表面特性的变化敏感。使用数学模型分析了 Rh (111) 和 Rh Al 2 O 3 上的 CO O 2 和 CO NO 反应的动力学数据，该数学模型解释了根据 CO、NO 和 O 2 与 Rh 表面相互作用的表面化学研究建立的各个基本反应步骤。该模型与表面化学文献中报道的参数值类似时，可以定量拟合单晶和负载型 Rh 催化剂上的 CO 氧化速率数据。 CO NO 在 Rh (111) 上的反应动力学也可以通过使用表面化学研究中的参数值的反应模型来很好地描述。然而，通过假设分子吸附的 NO 在负载型 Rh 上的解离速度比在 Rh 上慢得多 (111)，可以合理化负载型 Rh 上 CO NO 反应的速率数据。
The kinetics of the CO O 2 and CO NO reactions over single crystal Rh (111) and over alumina-supported Rh catalysts have been compared at realistic reactant pressures. For the CO O 2 reaction, there is excellent agreement between both the specific rates and activation energies measured for the two types of Rh catalysts. The CO NO reaction, on the other hand, exhibits substantially different activation energies and specific reaction rates between the single crystal and supported catalysts. This indicates that the kinetics of the CO NO reaction, unlike the CO O 2 reaction kinetics, are sensitive to changes in catalyst surface characteristics. The kinetic data for the CO O 2 and CO NO reactions over Rh (111) and Rh Al 2 O 3 were analyzed using mathematical models which account for the individual elementary reaction steps established from surface chemistry studies of the interactions of CO, NO, and O 2 with Rh surfaces. The model, when used with the parameter values similar to those reported in the surface chemistry literature, can quantitatively fit the CO oxidation rate data over both the single crystal and supported Rh catalysts. The kinetics of the CO NO reaction over Rh (111) can also be well described by a reaction model using parameter values taken from surface chemistry studies. However, the rate data for the CO NO reaction over supported Rh can be rationalized by assuming that the dissociation of molecularly adsorbed NO occurs much more slowly on supported Rh than on Rh (111).