caa a22 4500 606174133 CHVBK 20210128100736.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s11244-015-0371-3 doi (NATIONALLICENCE)springer-10.1007/s11244-015-0371-3 EXAFS Characterization of Palladium-on-Gold Catalysts Before and After Glycerol Oxidation [Elektronische Daten] [Zhun Zhao, Jeffrey Miller, Tianpin Wu, Neil Schweitzer, Michael Wong] Supported precious metal catalysts have been studied extensively for selective oxidation as a means to upgrade glycerol, a low-cost byproduct of biodiesel manufacture. We recently used a model bimetallic catalyst (Au nanoparticles decorated with Pd and immobilized onto carbon, "Pd-on-Au/C”) to study the metal nanostructure effects on glycerol oxidation. In this study, a detailed X-ray absorption spectroscopy analysis of Pd-on-Au catalysts before and after glycerol oxidation (60°C, 0.1M glycerol, 0.4M NaOH, and constant O2 flow at 1atm) is presented. Catalysts with two Pd surface coverages (60 and 150sc%) with comparable turnover frequency values were studied, along with the less active 4-nm Au/C and 4-nm Pd/C as control samples. Extended X-ray absorption fine structure analysis showed that there was no change to oxidation states and coordination numbers for 60 sc% Pd-on-Au/C and Au/C catalysts after contact with the glycerol reaction medium or after 3h of glycerol reaction. With a higher fraction of oxidized Pd (~40%) than 60 sc% Pd-on-Au/C (~25%), the 150 sc% catalyst showed some variation in oxidized Pd content before and after glycerol reaction. Pd/C grew in Pd particle size and became more oxidized after contacting reaction medium and after 3h reaction, contributing to its observed catalyst deactivation. Structural stability and catalytic activity are improved for the water-phase oxidation of glycerol and likely other alcohols when Pd is supported on Au, highlighting the potential advantages of using Au as a support for other catalytically active metals. Springer Science+Business Media New York, 2015 Nanoparticles nationallicence Palladium nationallicence Gold nationallicence Bimetallic nationallicence Glycerol nationallicence Oxidation nationallicence XAS nationallicence EXAFS nationallicence Zhao Zhun Department of Chemical and Biomolecular Engineering, Rice University, 6100 S. Main Street, 77005, Houston, TX, USA aut Miller Jeffrey Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut Wu Tianpin Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut Schweitzer Neil Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut Wong Michael Department of Chemical and Biomolecular Engineering, Rice University, 6100 S. Main Street, 77005, Houston, TX, USA aut Topics in Catalysis Springer US; http://www.springer-ny.com 58/4-6(2015-04-01), 302-313 1022-5528 58:4-6<302 2015 58 11244 https://doi.org/10.1007/s11244-015-0371-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11244-015-0371-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhao Zhun Department of Chemical and Biomolecular Engineering, Rice University, 6100 S. Main Street, 77005, Houston, TX, USA aut NATIONALLICENCE 700 1- Miller Jeffrey Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut NATIONALLICENCE 700 1- Wu Tianpin Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut NATIONALLICENCE 700 1- Schweitzer Neil Chemical Sciences and Engineering Division, Argonne National Laboratory, 60439, Argonne, IL, USA aut NATIONALLICENCE 700 1- Wong Michael Department of Chemical and Biomolecular Engineering, Rice University, 6100 S. Main Street, 77005, Houston, TX, USA aut NATIONALLICENCE 773 0- Topics in Catalysis Springer US; http://www.springer-ny.com 58/4-6(2015-04-01), 302-313 1022-5528 58:4-6<302 2015 58 11244