title: AuPt Alloy on TiO2: A Selective and Durable Catalyst for L-Sorbose Oxidation to 2-Keto-Gulonic Acid.
abstract: Pt nanoparticles were prepared by a sol immobilization route, deposited on supports with different acid/base properties (MgO, activated carbon, TiO2 , Al2O3, H-Mordenite), and tested in the selective oxidation of sorbose to 2-keto-gulonic acid (2-KGUA), an important precursor for vitamin C. In general, as the basicity of the support increased, a higher catalytic activity occurred. However, in most cases, a strong deactivation was observed. The best selectivity to 2-KGUA was observed with acidic supports (TiO2 and H-Mordenite) that were able to minimize the formation of C1/C2 products. We also demonstrated that, by alloying Pt to Au, it is possible to enhance significantly the selectivity of Pt-based catalysts. Moreover, the AuPt catalyst, unlike monometallic Pt, showed good stability in recycling because of the prevention of metal leaching during the reaction.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy.
authors.forename: Carine E
authors.initials: CE
authors.lastname: Chan-Thaw
authors.affiliation: Canadian Centre of Electron Microscopy, Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
authors.forename: Lidia E
authors.initials: LE
authors.lastname: Chinchilla
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Campisi
authors.affiliation: Canadian Centre of Electron Microscopy, Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4M1, Canada.
authors.forename: Gianluigi A
authors.initials: GA
authors.lastname: Botton
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Prati
authors.affiliation: Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK. DimitratosN@cardiff.ac.uk.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Dimitratos
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, 20133, Milano, Italy. alberto.villa@unimi.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Villa
mesh_terms: D000497:Alloys / Q000737:chemistry*; D002384:Catalysis; D006046:Gold / Q000737:chemistry*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D013013:Sorbose / Q000737:chemistry*; D013400:Sugar Acids / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D013400:Sugar Acids; C009495:titanium dioxide; C015252:gulonic acid; D010984:Platinum; D006046:Gold; D014025:Titanium; C011491:provitamin C; D013013:Sorbose
keywords: carbohydrates; gold; oxidation; platinum; supported catalysts