86278 20200609132538.0 doi 10.1016/j.mcat.2018.11.020 sideral 109835 ART-2018-109835 eng Meyer, C.I. Selective lactose oxidation in aqueous-phase over Ag-Au bimetallic nanoparticles supported on Al2O3 under mild reaction conditions 2018 Access copy available to the general public Unrestricted In this work, Au-Ag based catalysts supported on Al2O3 were prepared by a precipitation-deposition method at controlled pH and tested in the selective lactose (LA) oxidation to lactobionic acid (LB) in aqueous phase. Combining XPS and STEM-HAADF, it was found that there is an important surface Ag enrichment of bimetallic nanoparticles for bulk atomic ratios Au/(Au + Ag)>0.5. These bimetallic nanoparticles were active for the selective LA oxidation into LB and the maximum activity was reached with Au/(Au + Ag) = 0.9. In this case, the surface Au/(Au + Ag) atomic ratio was about 0.5, which indicates that there is the same amount of both elements at the active surface of the catalyst. Assuming that LA is chemisorbed on Au sites, and O2 on Ag ones, this particular surface atomic ratio would favor the interaction and reaction between both reactants. Thus, the synergistic effect between Au and Ag could explain the results of this study. A compensation effect between frequency factor and activation energy supports the existence of such synergy. If the atomic ratio is Au/(Au + Ag)=0.5, a layer of Ag deposits over the Au nanoparticles (core-shell structure) and the conversion of LA into LB drops to zero. info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 2.938 2018 CHEMISTRY, PHYSICAL 67 / 148 = 0.453 2018 Q2 T2 0.999 2018 Catalysis 2018 Q1 Process Chemistry and Technology 2018 Q1 Physical and Theoretical Chemistry 2018 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Regenhardt, S.A. Duarte, H.A. Zelin, J. (orcid)0000-0002-6873-5244 Sebastian, V. Universidad de Zaragoza Garetto, T.F. Marchi, A.J. 5005 555 Universidad de Zaragoza Dpto. Ing.Quím.Tecnol.Med.Amb. Área Ingeniería Química 481, 110249 (2018), [9 pp] Molecular Catalysis Molecular Catalysis 2468-8231 525790 http://zaguan.unizar.es/record/86278/files/texto_completo.pdf Postprint 43953 http://zaguan.unizar.es/record/86278/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:86278 articulos driver 2020-06-09-13:24:09 ARTICLE