Synthesis of highly dispersed gold nanoparticles on Al2O3, SiO2, and TiO2 for the solvent-free oxidation of benzyl alcohol under low metal loadings

• Published in: Journal of materials science Vol. 54; no. 1; pp. 238 - 251
• Main Authors: Gualteros, Jesus A. D., Garcia, Marco A. S., da Silva, Anderson G. M., Rodrigues, Thenner S., Cândido, Eduardo G., e Silva, Felipe A., Fonseca, Fabio C., Quiroz, Jhon, de Oliveira, Daniela C., de Torresi, Susana I. Córdoba, de Moura, Carla V. R., Camargo, Pedro H. C., de Moura, Edmilson M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.01.2019; Springer Nature B.V
• Subjects: Alcohol; Aluminum oxide; Benzyl alcohol; Catalysis; Catalysts; Characterization and Evaluation of Materials; Chemical Routes to Materials; Chemical synthesis; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Gold; Materials Science; Nanoparticles; Oxidation; Polymer Sciences; Recyclability; Selectivity; Silicon dioxide; Solid Mechanics; Solvents; Substrates; Titanium dioxide; Metal-support Interaction; Solvent-free Oxidation; Deposition Precipitation Method; Benzyl Alcohol Oxidation; High Catalytic Performance
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2827-x

We reported the organic template-free synthesis of gold (Au) nanoparticles (NPs) supported on TiO 2 , SiO 2 , and Al 2 O 3 displaying uniform Au sizes and high dispersions over the supports. The Au-based catalysts were prepared by a deposition–precipitation method using urea as the precipitating agent. In the next step, the solvent-free oxidation of benzyl alcohol was investigated as model reaction using only 0.08–0.05 mol% of Au loadings and oxygen (O 2 ) as the oxidant. Very high catalytic performances (TOF up to 443,624 h −1 ) could be achieved. Specifically, we investigated their catalytic activities, selectivity, and stabilities as well as the role of metal–support interactions over the performances. The conversion of the substrate was found to be associated with the nature of the employed support as the Au NPs presented similar sizes in all materials. A sub-stoichiometric amount of base was sufficient for the catalyst activation and the observation of the catalysts profile over the time enable insights on their recyclability performances. We believe this reported method represents a facile approach for the synthesis of uniform Au-supported catalysts displaying high performances.