Benzyl alcohol to benzaldehyde oxidation on MnOx clusters: Unraveling atomistic features

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

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.

Decomposition of guaiacol on a subnanometric platinum cluster: a DFT investigation followed by microkinetic analysis

The use of biomass as renewable feedstock for commodity chemicals may largely benefit from the successful development and application of heterogeneous catalysts for decomposition processes. The present investigation combines density functional theory and Christiansen-like microkinetic analysis to describe, at the atomistic level, the mechanisms related to the conversion of oxygenated biomass compounds to deoxygenated and semi-saturated hydrocarbons on a subnanometric Pt10 cluster. The DFT calculations and the kinetic analysis based on the evaluated free energy variations, associated with both elementary step barriers and rearrangement/desorption processes occurring on the cluster, suggest that benzene is the preferred product, together with a compound still bearing oxygen, cyclopentadienone, which would form as a minor product only at high temperature. Other than highlighting the role of the peculiar interaction between carbon and platinum, the reported investigation underlines the importance of cluster fluxionality and reorganization ability in promoting catalyzed reactions.

Structural, energetic and kinetic database of catalytic reactions: Benzyl alcohol to benzaldehyde oxidation on MnO x clusters

Data here reported are connected with the research article "Benzyl Alcohol to Benzaldehyde Oxidation on MnOx Clusters: Unraveling Atomistic Features" Gueci et al. [1]. This work described and discussed structural and energetic results, calculated by Density Functional Theory (DFT). In order to get kinetic information, DFT results were refined by an original approach, which will be shortly described in the following article. The crossed analysis of experimental and computational energetic and kinetic data allowed to (i) reconstruct the complicated lattice that connects the primary and secondary mechanisms of the reaction and (ii) identify alternative process pathways capable of by-passing parasitic mechanisms, decreasing selectivity. On the other hand, the data here presented show what is the basic information necessary to obtain the modeling of a complex process of heterogeneous catalysis. Moreover, they can be used either to verify the validity of the discussion outlined in the original article Gueci et al. [1] or as a starting point to computationally explore alternative routes and the related kinetics of the same oxidation processes, in the aim to further optimize the corresponding experimental approach.