Spatiotemporal patterns within a porous catalyst: dynamic carbon monoxide oxidation in a single-pellet reactor

摘要: Competitive adsorption and reactant inhibition are expected to couple with di1usion resistance form complex patterns within porous adsorbents catalysts, especially under dynamic conditions. CO oxidation over Pt=Al2O3, which exhibits these surface processes, was studied in this work. A miniaturized single-pellet reactor used continuously directly measure gas concentration gradients a pellet as feed composition varied. Responses of nonadsorbing species were analyzed order determine coe8cients. Single-species responses provided starting estimates parameters. Reaction experiments performed at 398–448 K maximum O2 pressures 16 110 Pa, respectively. An elementary-step di1usion–reaction model simulate experimental results. bimodal distribution active sites proposed explain the transient responses. Analysis showed that could not have been detected by steady-state experiments. The intrapellet spatiotemporal predicted model, con;rmed comparison measurements across pellet, provide understanding coupling between di1usion, adsorption, reaction pellet. Methods discussed reduce computational requirements, including assumption quasi-equilibrium reduction surface-to-gas capacity ratio. ? 2002 Elsevier Science Ltd. All rights reserved.