Vol.:(0123456789) Research on Chemical Intermediates https://doi.org/10.1007/s11164-018-3686-4 1 3 Surface reconstruction of Pt–Sn nanoparticles supported on Al 2 O 3 in the presence of carbon monoxide Abdellah Arrahli 2  · Abdelhak Kherbeche 2  · Daniel Bianchi 1 Received: 27 September 2018 / Accepted: 20 November 2018 © Springer Nature B.V. 2018 Abstract FTIR spectroscopy and volumetric measurements are used to study the adsorption of CO (mainly 1% CO/He) in the temperature range 300–713 K on a 1.2% Pt–2.7% Sn/Al 2 O 3 solid reduced in H 2 at 713 K leading from XRD to PtSn bimetallic par- ticles. This reveals the changes in the adsorption properties of the Pt sites for CO adsorption by comparison with monometallic Pt/Al 2 O 3 solids and the stability of the Pt–Sn bimetallic particles in the presence of CO. At 300 K, FTIR spectroscopy shows that the insertion of Sn leads to (a) the total disappearance of the Pt sites forming bridged CO species (ascribed to a geometric efect of Sn) and (b) a signif- cant shift in the position of the IR band of linear CO species on Pt sites from 2066 to 2044 cm −1 on Pt and Pt–Sn particles, respectively, ascribed to diferent adsorbed species, namely L Pt and L1 Pt–Sn, respectively. Moreover, it is shown that the insertion of Sn is associated with the decrease in the amount (in µmol/g of platinum) of Pt adsorption sites for CO adsorption. The evolution of the IR band of the L1 Pt–Sn CO species with the increase in T a in isobaric conditions reveals a modifcation of the surface of the Pt–Sn particles for T a > ≈  460 K ascribed to enrichment in Pt° due to a surface reconstruction. The Pt sites of the reconstructed surface are characterized by an IR band at 2057 cm −1 after adsorption of CO at 300 K ascribed to a linear CO species named L2 Pt–Sn . The reconstructed surface is stable in the presence of CO in the range 300–713 K and disappears by hydrogen reduction at 713 K. Successive surface reconstruction/hydrogen reduction at 713 K cycles lead to an ageing of the Pt–Sn particles associated with a progressive decrease in the amount of Pt° sites on the freshly prepared and reconstructed Pt–Sn particles. It is shown that the recon- struction of the Pt–Sn particles is probably due to the formation of SnO x species via oxygen species coming mainly from the hydroxyls groups of the support. * Abdelhak Kherbeche abdelhak.kherbeche@usmba.ac.ma 1 Institut de Recherches sur la Catalyse et l’Environnement de Lyon (IRCELYON), UMR 5256, CNRS, Université Claude Bernard Lyon I, Bat. Chevreul, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France 2 Laboratoire de Catalyse, Matériaux et Environnement (LCME), Université Sidi Mohammed Ben Abdellah, Fès, Route d’Imouzzer, BP 2427, Fes, Morocco