Session Overview |
Wednesday, July 20 |
13:30 |
Operando X-ray absorption spectroscopy and in situ transmission electron microscopy reveal reversible agglomeration of gold nanoparticles for low-temperature water-gas shift reaction
* James Carter, Cardiff University, United Kingdom Ali M. Abdel-Mageed, Leibniz Institute for Catalysis (LIKAT Rostock), Germany Dan Zhou, DENSsolutions B.V., Netherlands David J. Morgan, Max Planck-Cardiff Centre on the Fundamentals of Heterogeneous Catalysis FUNCAT, Cardiff Catalysis Institute, School of Chemistry, Cardiff University, United Kingdom Xi Liu, School of Chemistry and Chemical Engineering, In situ Center for Physical Sciences, Shanghai Jiao Tong University, China (People's Republic of) Joachim Bansmann, Institute of Surface Chemistry and Catalysis, Ulm University, Germany Shilong Chen, Institute of Inorganic Chemistry, Kiel University, Max-Eyth-Straße 2, D-24118, Germany R.Jürgen Behm, Institute of Theoretical Chemistry, Ulm University, Germany Graham J. Hutchings, Max Planck-Cardiff Centre on the Fundamentals of Heterogeneous Catalysis FUNCAT, Cardiff Catalysis Institute, School of Chemistry, Cardiff University, United Kingdom Using operando XAS and in situ TEM we investigated the dynamics of supported gold nanoparticles during the low-temperature water-gas shift reaction at 150 C. We show for the first time that supported gold nanoparticles can re-disperse using a simple regeneration treatment of O2/N2 at 300 C. These findings are significant in the field of gold catalysis as it demonstrates that agglomeration of nanoparticles is not an irreversible deactivation mechanism, as previously thought, and paves the way for extending the life time of gold catalysts in various applications. |
13:45 |
Strategies to enhance the efficiency of gold catalysts in base-free oxidation of bio-based compounds
Robert Wojcieszak, Centre National de la Recherche Scientifique, France Liane M. Rossi, University of Sao Paulo, Brazil Camila Ferraz, Université de Lille, France * Sara Navarro Jaen, Centre National de la Recherche Scientifique, France Mohamed Nawfal Ghazzal, University of Paris Saclay, France Franck Dumeignil, University of Lille, France Ivaldo Itabaiana Jr, Centre National de la Recherche Scientifique, France The aerobic oxidation of bio-based compounds requires generally several tandem oxidation steps. Another issue is the requirement of an excess amount of a base additive. Strategies to prevent the use of base consist in adopting a basic and/or nanosized support and/or by adding a second metal (bimetallic) and/or engineering of new type of catalysts (oxide coating). We have prepared a series of Au and Au-based bimetallic supported nanoparticles by well-known sol-immobilization method. In addition, Au/TiO2 monometallic catalyst was also modified by coating the gold with a TiO2 shell. |
14:00 |
Supported AuCu NPs as promising catalyst for the oxidation of cyclohexane to K-A oil
* Laura Prati, University of Milan, Italy Marta Stucchi, University of Milan, Italy Alessandro Vomeri, University of Milan, Italy A bimetallic AuCu/Al2O3 catalyst was tested in the oxidation of cyclohexane, working at mild conditions of 120 °C and 4 bar of O2. The combination of the catalyst with a very small amount of benzaldehyde used as cheaper and non-toxic radical initiator allowed to obtain a very high productivity of cyclohexanol and cyclohexanone (45 mmol*mL/mgmet*h) with a selectivity of 94%. Moreover, comparing the catalysed reaction with the non-catalysed one, the role of the catalyst has been disclosed. |