CO-PROX on MnO2 catalysts: DFT-based microkinetic and experimental macrokinetic approaches

A microkinetic analysis in terms of DFT-calculated temperature-dependent Gibbs free energies was performed for the oxidation reactions of CO and H2 on a model Mn4O8 cluster. Apparent activation energies data predict a peculiar CO preferential oxidation pattern of Mn(IV) sites in presence of hydrogen (PROX) substantiated by the unprecedented PROX behavior of a nanocomposite MnCeOx catalyst in the range of 353-423 K under both ideal and real process conditions. Micro- and macrokinetic data on the "model" cluster and "real" catalyst are discussed.