Catalytic Activity of Mono- and Bi-Metallic Nanoparticles Synthesized via Microemulsions
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Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart 70569, Germany
2
Fakultät II, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Berlin 10623, Germany
*
Author to whom correspondence should be addressed.
Catalysts 2014, 4(3), 256-275; https://doi.org/10.3390/catal4030256
Received: 19 March 2014 / Revised: 9 May 2014 / Accepted: 13 June 2014 / Published: 1 July 2014
(This article belongs to the Special Issue Synthesis of Nanostructured Catalytic Materials from Microemulsions)
Water-in-oil (w/o) microemulsions were used as a template for the synthesis of mono- and bi-metallic nanoparticles. For that purpose, w/o-microemulsions containing H2PtCl6, H2PtCl6 + Pb(NO3)2 and H2PtCl6 + Bi(NO)3, respectively, were mixed with a w/o-microemulsion containing the reducing agent, NaBH4. The results revealed that it is possible to synthesize Pt, PtPb and PtBi nanoparticles of ~3–8 nm in diameter at temperatures of about 30°C. The catalytic properties of the bimetallic PtBi and PtPb nanoparticles were studied and compared with monometallic platinum nanoparticles. Firstly, the electrochemical oxidation of formic acid to carbon monoxide was investigated, and it was found that the resistance of the PtBi and PtPb nanoparticles against the catalyst-poisoning carbon monoxide was significantly higher compared to the Pt nanoparticles. Secondly, investigating the reduction of 4-nitrophenol to 4-aminophenol,we found that the bimetallic NPs are most active at 23 °C, while the order of the activity changes at higher temperatures, i.e., that the Pt nanoparticles are the most active ones at 36 and 49 °C. Furthermore, we observed a strong influence of the support, which was either a polymer or Al2O3. Thirdly, for the hydrogenation of allylbenzene to propylbenzene, the monometallic Pt NPs turned out to be the most active catalysts, followed by the PtPb and PtBi NPs. Comparing the two bimetallic nanoparticles, one sees that the PtPb NPs are significantly more active than the respective PtBi NPs.
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MDPI and ACS Style
König, R.Y.; Schwarze, M.; Schomäcker, R.; Stubenrauch, C. Catalytic Activity of Mono- and Bi-Metallic Nanoparticles Synthesized via Microemulsions. Catalysts 2014, 4, 256-275.
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