Platinum, ammonia conversion reaction rate

Surface-science studies succeeded to identify many of the molecular ingredients of surface catalyzed reactions. Each catalyst system that is responsible for carrying out important chemical reactions with high turnover rate (activity) and selectivity has unique structural features and composition. In order to demonstrate how these systems operate, we shall review what is known about (a) ammonia synthesis catalyzed by iron, (b) the selective hydrogenation of carbon monoxide to various hydrocarbons, and (c) platinum-catalyzed conversion of hydrocarbons to various selected products. 

The number of publications on the (intrinsic) rate of NH3 oxidation on platinum at conditions relevant for technical ammonia oxidation is very limited. Here we use the data given by Kraenert (2005) for NO formation at atmospheric pressure (0.1 mol NO s at 385 °C, 3% NH3, 6% O2). If we assume a first-order reaction (kA = Fno/Cnhs) and activation energy of 80 kj mol [estimate based on the data of Kraenert (2005)] we obtain a rate constant for NH3 conversion into NO of ... 

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