In Situ Synthesis of Bimetallic Hybrid Nanocatalysts on a Paper-Structured Matrix for Catalytic Applications

Hirotaka Koga,Yuuka Umemura,Takuya Kitaoka

doi:10.3390/catal1010069

Hirotaka Koga, Yuuka Umemura + Show 1 more

Open Access

https://doi.org/10.3390/catal1010069

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Journal: Catalysts	Publication Date: Nov 25, 2011
Citations: 58	License type: CC BY 4.0

Affiliation: The University of Tokyo, Kyushu University

Abstract

Bimetallic nanoparticles have attracted significant attention as their electrochemical and catalytic properties being superior to those of the individual component nanoparticles. In this study, gold-silver hybrid nanoparticles (AuAgNPs) with an Aucore-Agshell nanostructure were successfully synthesized on zinc oxide (ZnO) whiskers. The as-prepared nanocatalyst, denoted AuAgNPs@ZnO whisker, exhibits an excellent catalytic efficiency in the aqueous reduction of 4-nitrophenol to 4-aminophenol; the turnover frequency was up to 40 times higher than that of each component nanoparticle. Their unique features were attributed to the electronic ligand effect at the bimetallic interface. In addition, the AuAgNPs were synthesized on a ZnO whisker-containing paper with a fiber-network microstructure, which was prepared via a papermaking technique. The paper-structured AuAgNPs composite possessed both a paper-like practical utility and a good catalytic performance. Furthermore, the on-paper synthesis process for these bimetallic nanocatalysts is facile. These easy-to-handle nanocatalyst hybrid composites are expected to find a wide range of applications in various chemical and catalytic processes.

Highlights

Metal catalysts play a key role in a wide range of chemical industries, since they enable the environmentally friendly conversion of various chemical substances
Toshima et al have reported that core-shell bimetallic NPs exhibit a higher catalytic activity than the monometallic counterparts because the catalytic activity of the shell atoms can be electronically influenced by the core atoms [21,22,23,24,25]
zinc oxide (ZnO) whiskers were added to a neutral solution of HAuCl4 and the suspension was heated at reflux at 100 °C for 48 h before filtration

Summary

Introduction

Metal catalysts play a key role in a wide range of chemical industries, since they enable the environmentally friendly conversion of various chemical substances. The as-prepared paper composite, denoted as AuNPs@ZnO paper, is like a flexible and easy-to-handle cardboard, and possesses a porous fiber-network microstructure In both the liquid-phase 4-NP reduction process and the gas-phase CO oxidation process, the AuNPs@ZnO paper exhibited excellent practical utility and high catalytic reactivity [30,34,35]. This facile technique can be extended to various metal NPs, and has potential applicability for the on-paper synthesis of bimetallic hybrid nanocatalysts for further functionalization. The catalytic performance of the as-prepared AuAgNPs@ZnO whiskers and paper were evaluated in the liquid-phase reduction of 4-NP

AuAgNPs Synthesis on the ZnO Whiskers

In Situ Synthesis of AuAgNPs onto ZnO Paper

Materials

Preparation of ZnO Paper by a Papermaking Technique

Catalytic Performance Test

Analyses

Conclusions