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

Authors: Jianming Zhang, Guozhu Chen, Mohamed Chaker, Federico Rosei, Dongling Ma

Abstract:
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.

Keywords:
Au nanoparticle
CeO₂
Hydrogenation
Nitrophenol reduction
Laser ablation

Published in: Applied Catalysis B: Environmental (Volumes 132–133, Pages 1-552, 27 March 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

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

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