Global Activity Search Uncovers Reaction Induced Concomitant Catalyst Restructuring for Alkane Dissociation on Model Pt Catalysts

Abstract

Although there is evidence that catalytic active sites can restructure under reaction conditions, their optimal reconstruction to provide the lowest activation barrier is still unclear. Here, we show with methane activation on supported Pt clusters and by an explicit sampling of cluster configurations at the transition state that important restructuring is required to reach the most active transition state. The capability of the cluster to reconstruct, simultaneously with the C–H dissociation, is a key aspect for catalytic activity. We underline two types of reconstructions, concomitant or independent, depending on whether they emerge in or off the course of reactive trajectories. The concomitant reconstructions depict the significant rearrangement of the catalyst itself as part of the reaction coordinate and play critical roles in the most competitive pathways. The best active sites can only be found in the course of the reactive trajectories and not from the equilibrium geometry prior to the reaction.

Active Site Fluxional Restructuring as a New Paradigm in Triggering Reaction Activity for Nanocluster Catalysis

“…Since previous theoretical studies in the literature relied on electronic and geometrical structure of the equilibrium geometry, the new activity that originated from the fluctuation-driven fluxionality has been missed. Without the extensive sampling on the elastic fluxionality of the clusters, the reaction barrier for CH activation is overestimated by 0.26 eV 2.…”

Enhancing activity, selectivity and stability of palladium catalysts in formic acid decomposition: Effect of support functionalization

“…The extensive conformational study of the supported nanoparticle restricted its size to 15 atoms. To determine the most stable initial shape of the Pd15 cluster on pristine graphene, in addition to moieties that maximized the exposure of the most stable facets and those based on previous reports, an unbiased genetic algorithm (GA) was employed to explore almost 100 independent structures [51] [52]. A 15 Å of vacuum perpendicular to the slab was added to avoid any interaction with periodic images Clusters adhesion energy (EADH) was calculated as the difference between the combined system (cluster attached to the surface) and the isolated species (clusters and selected surface in gas phase with exactly the same geometry as the combined model).…”

Disclosing the Role of Gold on Palladium – Gold Alloyed Supported Catalysts in Formic Acid Decomposition

“…To determine the most stable initial shapes and the distribution of species within the NPs, we employed an unbiased genetic algorithm (GA) to explored up to 100 independent structures for each Pd, Au and AuPd clusters, besides moieties that maximized the exposure of the most stable facets, i. e., (111) and those based on previous reports [54] . We recognized that not all possible configurations were simulated, nevertheless, we proved during the presented research that these clusters are highly dynamic and their reactivity is not related directly to the rigid morphology of the global energy minima's structure [55] . We added 15 Å of vacuum perpendicular to the carbon slab to avoid any spurious interaction with periodic images.…”