Pseudo-2-Fold Surface of the AlCo Catalyst: Structure, Stability, and Hydrogen Adsorption.
Fiche publication
Date publication
septembre 2020
Journal
ACS applied materials & interfaces
Auteurs
Membres identifiés du Cancéropôle Est :
Pr GAUDRY Emilie
Tous les auteurs :
Chatelier C, Garreau Y, Vlad A, Ledieu J, Resta A, Fournée V, de Weerd MC, Coati A, Gaudry É
Lien Pubmed
Résumé
A few low-order approximants to decagonal quasicrystals have been shown to provide excellent activity and selectivity for the hydrogenation of alkenes and alkynes. It is the case for the AlCo compound, for which the catalytic properties of the pseudo-2-fold orientation have been revealed to be among the best. A combination of surface science studies, including surface X-ray diffraction, and calculations based on density functional theory is used here to derive an atomistic model for the pseudo-2-fold -AlCo surface, whose faceted and columnar structure is found very similar to the one of the 2-fold surface of the -Al-Ni-Co quasicrystal. Facets substantially stabilize the system, with energies in the range 1.19-1.31 J/m, i.e., much smaller than the ones of the pseudo-10-fold (1.49-1.68 J/m) and pseudo-2-fold (1.66 J/m) surfaces. Faceting is also a main factor at the origin of the AlCo catalytic performances, as illustrated by the comparison of the pseudo-10-fold, pseudo-2-fold and facet potential energy maps for hydrogen adsorption. This work gives insights toward the design of complex intermetallic catalysts through surface nanostructuration for optimized catalytic performances.
Mots clés
catalysis, density functional theory, hydrogen adsorption, intermetallics, scanning tunneling microscopy, surface X-ray diffraction, surfaces
Référence
ACS Appl Mater Interfaces. 2020 Sep 2;12(35):39787-39797