Tailoring Gold Nanoparticle Characteristics and the Impact on Aqueous-Phase Oxidation of Glycerol

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• 作者：Scott M. Rogers ; C. Richard A. Catlow ; Carine E. Chan-Thaw ; Diego Gianolio ; Emma K. Gibson ; Anna L. Gould ; Nan Jian ; Andrew J. Logsdail ; Richard E. Palmer ; Laura Prati ; Nikolaos Dimitratos ; Alberto Villa ; Peter P. Wells
• 刊名：ACS Catalysis
• 出版年：2015
• 出版时间：July 2, 2015
• 年：2015
• 卷：5
• 期：7
• 页码：4377-4384
• 全文大小：432K
• ISSN：2155-5435

文摘

Poly(vinyl alcohol) (PVA)-stabilized Au nanoparticles (NPs) were synthesized by colloidal methods in which temperature variations (鈭?5 to 75 掳C) and mixed H₂O/EtOH solvent ratios (0, 50, and 100 vol/vol) were used. The resulting Au NPs were immobilized on TiO₂ (P25), and their catalytic performance was investigated for the liquid phase oxidation of glycerol. For each unique solvent system, there was a systematic increase in the average Au particle diameter as the temperature of the colloidal preparation increased. Generation of the Au NPs in H₂O at 1 掳C resulted in a high observed activity compared with current Au/TiO₂ catalysts (turnover frequency = 915 h^鈥?). Interestingly, Au catalysts with similar average particle sizes but prepared under different conditions had contrasting catalytic performance. For the most active catalyst, aberration-corrected high angle annular dark field scanning transmission electron microscopy analysis identified the presence of isolated Au clusters (from 1 to 5 atoms) for the first time using a modified colloidal method, which was supported by experimental and computational CO adsorption studies. It is proposed that the variations in the populations of these species, in combination with other solvent/PVA effects, is responsible for the contrasting catalytic properties.