Influence of Au Particle Size on Au/TiO2 Catalysts for CO Oxidation

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• 作者：Mingming Du ; Daohua Sun ; Hongwei Yang ; Jiale Huang ; Xiaolian Jing ; Tareque Odoom-Wubah ; Haitao Wang ; Lishan Jia ; Qingbiao Li
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 21, 2014
• 年：2014
• 卷：118
• 期：33
• 页码：19150-19157
• 全文大小：626K
• ISSN：1932-7455

文摘

A series of Au/TiO₂ catalysts for CO oxidation with same Au loading but different Au nanoparticles (NPs) sizes were prepared by varying the calcination temperatures and biomass concentration via a biosynthetic approach. The resulting catalysts were characterized by DRUV鈥搗is, TEM, and TG techniques. The experimental results showed that the activity of the gold catalysts for CO oxidation was very sensitive to the particle size. Among the tested catalysts, the one with mean size of 3.8 nm was the most active. As determined by TEM, the contact boundary between the Au NPs and the TiO₂ support was related to the size of the Au NPs. For the most active catalyst, hemispherical Au NPs (3.8 卤 0.6 nm) had the best contact boundary with the TiO₂ support, yielding the longest perimeter interface, suggesting that the contact boundary was the most critical factor for the CO oxidation. The in-situ FTIR study of CO adsorption on the catalysts showed that CO was not adsorbed on the Au surface. This might be due to the modification of the Au/TiO₂ catalysts by the residual biomass. The intensity of the peak at 2185 cm^鈥? for the Au/TiO₂ catalysts with the longest perimeter interface was highest, demonstrating that the Au鈥揟iO₂ contact boundary played an important role in the adsorption of CO.