Evaluation of kinetic models for the partial oxidation of methane to synthesis gas over a Pt/PrCeZrO_x catalyst coated on a triangular monolith

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• 作者：Elena L. Gubanova ; Yves Schuurman ; Vladislav A. Sadykov ; Claude Mirodatos ; Andre C. van Veen
• 关键词：Kinetic model ; Reaction mechanism ; Platinum ; Fluorite structured support ; Oxygen storage material
• 刊名：Chemical Engineering Journal
• 出版年：2009
• 出版时间：15 November 2009
• 年：2009
• 卷：154
• 期：1-3
• 页码：174-184
• 全文大小：743 K

文摘

The evaluation of kinetic models for the partial oxidation of methane to synthesis gas over a 1.4-wt % Pt/Pr_0.3Ce_0.35Zr_0.35O_x catalyst coated on the surface of a triangular corundum channel is presented. The mathematical form of the tested models accounts for global surface steps. The formulation of reaction steps for two cases proposed in the literature contained lumped formulations to restrict reasonably the number of parameters to estimate. One mechanism considering an oxygen assisted methane activation and another considering methane dissociation without oxygen involvement were tested. In both cases a satisfying description of the experimental data was possible, suggesting that the initial activation of methane is of less importance for the overall progress of the partial oxidation than the oxidation of carbonaceous intermediates to adsorbed carbon monoxide assumed in both cases. Comparing the kinetics over unsupported platinum extensively reported in literature to the data over the 1.4-wt % Pt/Pr_0.3Ce_0.35Zr_0.35O_x catalyst in this work reveals significantly different rates for oxygen adsorption and carbon monoxide oxidation. These differences are explained by considering the active role the ceria plays in the catalyst performance.