Gold nanoparticle decorated ceria nanotubes with significantly high catalytic activity for the reduction of nitrophenol and mechanism study

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• 作者：Jianming Zhang ; Guozhu Chen ; ^{chen@emt.inrs.ca} ; Mohamed Chaker ; Federico Rosei ; Dongling Ma ; ^{ma@emt.inrs.ca}
• 关键词：Au nanoparticle ; CeO2 ; Hydrogenation ; Nitrophenol reduction ; Laser ablation
• 刊名：Applied Catalysis B: Environmental
• 出版年：2013
• 出版时间：27 March, 2013
• 年：2013
• 卷：132-133
• 期：Complete
• 页码：107-115
• 全文大小：1302 K

文摘

We report the preparation and catalytic properties of a new nanostructured catalyst, made of small (¡«5 nm in diameter) and uniform gold nanoparticles (AuNPs) and ceria nanotubes (CeO₂ NTs). ¡°Surfactant-free¡± AuNPs fabricated by pulsed laser ablation in liquid (PLAL) on a bulk Au target are efficiently assembled onto the surface of CeO₂ NTs without performing any surface functionalization of either component to promote their coupling, thanks to the presence of OH on the PLAL-AuNPs. The reduction reaction of 4-nitrophenol into 4-aminophenol catalyzed by our PLAL-AuNP/CeO₂-NT catalyst exhibits remarkably higher reaction rate in comparison to that catalyzed by similar catalysts composed of chemically prepared AuNPs (Chem-AuNPs) as an active phase and/or commercially available CeO₂ powder as support. Their superior catalytic activity is found to be due to the unique, relatively ¡°bare¡± surface of the PLAL-AuNPs as well as oxidized Au species induced by the strong interaction between the ¡°barrier-free¡± surface of PLAL-AuNPs and surface defects (oxygen vacancies) of CeO₂ NTs. The important role of unique surface chemistry of PLAL-AuNPs in catalysis was further demonstrated in CO oxidation reaction in gas phase. Our results suggest that the use of PLAL-AuNPs enables easy and efficient attachment of AuNPs onto the surface of the CeO₂ NTs and their unique combination leads to the development of highly efficient catalysts. Our design and fabrication of the nanocatalysts take full advantage of the unique features of the PLAL-AuNPs and potentially constitute a general and efficient route to prepare other metal-NP/metal-oxide-support catalysts, which can therefore largely expand the applications of PLAL-noble metal NPs in catalysis.