Pt–Sn Nanoparticles Decorated Carbon Nanotubes as Electrocatalysts with Enhanced Catalytic Activity

Abstract

The catalytic activities of Pt−Sn alloy nanoparticles with different Pt:Sn atomic ratios, prepared by a pulse microwave-assisted polyol (MP) method, in the oxygen reduction reaction and oxidation of methanol and formic acid have been examined by using cyclic voltammetry. The pulse MP approach enables the formation of Pt−Sn alloy nanoparticles with well-defined atomic ratios over the surface of carbon nanotubes. The as-prepared Pt−Sn nanoparticles display a homogeneous dispersion with a narrow crystalline size in the range of 2.72−3.66 nm. An appropriate amount of Sn dopants (25 at. %) facilitates not only the catalytic activity but also the long-term antipoisoning ability as compared with pure Pt catalyst. The improved performance of Pt−Sn alloy catalyst is attributed to the bifunctional mechanism of bimetallic catalysts; that is, CO adsorption mainly occurs on Pt sites, while OH formation would take place preferentially on the Sn sites. Thus, the introduction of Sn offers one pathway to strip CO from the Pt−CO sites, thereby raising the CO tolerance. Without any treatment, the pulse MP synthesis emerges as a feasible method to prepare Pt−Sn catalysts with excellent catalytic activity and long-term durability for fuel cell applications.

Fast Synthesis of Binary Pt–Sn Nanocatalysts onto Graphene Sheets for Promoted Catalytic Activity

“…The Pt 75 Sn 25 @GN catalyst is capable of displaying not only high ESA value but also excellent ORR catalytic activity. The optimal atomic ratio (secondary element: $25 at%) in Pt-Ru [32] and Pt-Sn [19] catalysts onto carbon nanotubes has been confirmed by previous studies.…”

“…The pH value of GO slurry was then adjusted to pH= 10 by adding sufficient amount of 0.04 M KOH. The GO slurry was placed in the center of a household microwave oven (Tatung Co., maximal power: 900 W, frequency: 2.45 GHz) and then heated under microwave irradiation of 720 W. A pulse microwave process was adopted to synthesize Pt and Pt-Sn nanoparticles onto GNs, which is similar to the Pt-Sn deposits onto carbon nanotubes as reported in our previous study [19]. Herein the pulse parameters were power-on time of 3 s, power-off time of 5 s, and total cycle number of 100 cycles.…”

“…Recently, pioneering studies have adopted the microwave method to deposit Pt-Sn bimetallic catalysts on carbon nanotubes for electro-oxidation of alcohol [18] and formic acid [19], showing superior electrocatalytic performance. It has been reported that microwave-assisted approach to prepare metallic or alloy nanoparticles is an efficient method due to its energy efficiency, time-saving, uniformity, simplicity in execution, and use of inexpensive solvent (ethylene glycol, EG) [20][21][22].…”

Microwave synthesis of copper network onto lithium iron phosphate cathode materials for improved electrochemical performance

“…Recently, our pervious studies have proposed a facile microwave-assisted (MA) technique to prepare metallic nanoparticles (e.g., PteSn alloy and Ag nanorod) onto carbon supports [11,12] and ZnO layer over spinel lithium titanate powders [13]. Generally, the MA method is capable of depositing metallic nanoparticles with good uniformity on different supports due to its energy efficiency, uniformity, and simplicity in execution [14,15].…”

Carbon nanotube-Cu hybrids enhanced catalytic activity in aqueous media

“…Furthermore, the combination of two nanomaterials such as CNTs and Cu-NPs could result in a novel hybrid material useful in the fabrication of sensors or catalysts [11,12]. Examples of catalytic applications can be found with Pd-and Pt-NPs anchored to CNTs [13][14][15][16][17], and alloys of Pt-Sn [18], Pt-Co [19], and Fe 3 O 4 -Pt [20]. More recently, using a polymer assisted route, a variety of metal NPs (e.g.…”