Role of Sn atoms on the Crotonaldehyde (2-Butenal) adsorption over bimetallic catalysts PtSn(110), Pt3Sn(111)/Pt(111), Pt3Sn(111) and PtSn4(010): A periodic DFT study

In this study, adsorption of crotonaldehyde (C4H6O) on catalysts composed by Pt and Sn was examined using periodic density functional theory (DFT) calculations. Therefore, different compositions of catalysts were evaluated such as, PtSn(110), Pt3Sn(111), PtSn4(010) and Pt3Sn(111)/Pt(111) surfaces. The surfaces were modeled with the aim to get new insight of the Pt atom dilution in the surface maintaining the catalytic activity. In all studied systems, when Sn atoms are located on the surface layer, O(cro)-Sn interactions occur and the C(cro)-Pt distances get shorter. For larger abundance of Sn in PtSn4(010) produced a considerable decrease of the interacting configurations number towards Pt atoms, being the most observed interaction the O(cro)-Pt . The results allowed us to show that the interactions might induce the conversion of crotonaldehyde towards hydrogenation products, i.e. those interactions through the carbonyl oxygen with the catalysts could result in crotyl alcohol, while those with CC double bond on the surface could produce butyraldehyde or 1-butanol. The study provides the first insights for the understanding of crotonaldehyde adsorption on PtxSny at the atomic level, particularly the role of Sn adsorption sites.