Alternative Algebraic Perspectives on CO/H2 PROX over MnO2 Composite Catalysts

Abstract

This study presents a graph-based approach to investigate the steady-state kinetics of the preferential CO oxidation process in H2 (PROX) occurring on a MnO2 model fragment with manganese centers at varying oxidation states, simulating the surface Mn(IV) active sites of a composite MnO2-CeO2 catalyst previously used in experimental applications. A novel modeling approach, termed DFT graph-based kinetic analysis (DFT-GKA), is introduced. It utilizes free activation energy (ΔG⧧) values to characterize linear elementary events, supposed at pseudosteady-state, in this complex reaction system, as determined through density functional theory (DFT) integrated by thermochemical calculations. The implementation of this model is achieved using a homemade Common Lisp code, specifically designed for efficient manipulation of long lists essential for the analysis. Finally, the comprehensive ab initio DFT kinetic descriptors related to the CO/H2 PROX catalytic process on the manganese oxide fragments are discussed, highlighting their significance for future research and applications.