Highly Active Pt3Pb and Core-Shell Pt3Pb-Pt Electrocatalysts for Formic Acid Oxidation
ABSTRACT Formic acid is a promising chemical fuel for fuel cell applications. However, due to the dominance of the indirect reaction pathway and strong poisoning effects, the development of direct formic acid fuel cells has been impeded by the low activity of existing electrocatalysts at desirable operating voltage. We report the first synthesis of Pt(3)Pb nanocrystals through solution phase synthesis and show they are highly efficient formic acid oxidation electrocatalysts. The activity can be further improved by manipulating the Pt(3)Pb-Pt core-shell structure. Combined experimental and theoretical studies suggest that the high activity from Pt(3)Pb and the Pt-Pb core-shell nanocrystals results from the elimination of CO poisoning and decreased barriers for the dehydrogenation steps. Therefore, the Pt(3)Pb and Pt-Pb core-shell nanocrystals can improve the performance of direct formic acid fuel cells at desired operating voltage to enable their practical application.
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ABSTRACT: Herein, template or surfactant free synthesis of porous platinum nanostructures has been reported from a liquid–liquid interfacial synthetic technique. Here the progress of the Pt4+ reduction has been governed by an aromaticity driven pathway of 2,4 dihydropyridine ester (DHPE) in dichloromethane (DCM). Thus morphologically two different Pt nanostructures at the liquid-liquid interface are evolved depending upon the imposed reaction conditions (UV irradiation or mild heat). Comparative methanol oxidation reaction (MOR) in basic condition illustrates that porous platinum nanochains (Pt NCs), synthesized under heat, show 14.63 and 1.43 times higher mass activity than platinum nanoparticles (Pt NPs) and platinum nanoflowers (Pt NFs), synthesized under UV irradiation. Furthermore Pt NCs exhibit remarkable catalytic stability for MOR and also superior catalytic efficiency for formic acid oxidation (FAOR) leaving aside CO poisoning. The assembly of Pt nanowires generates porous Pt NCs which provide the oppertunity for better utilization of expensive Pt in electrocatalysis in terms of its higher mass activity and stability compared to even commercial Pt/C catalyst. Thus our proposed synthetic procedure for naked and porous platinum nanostructure foretells its practical fuel cell applicationElectrochimica Acta 02/2015; 159:52-60. DOI:10.1016/j.electacta.2015.02.007 · 4.09 Impact Factor
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ABSTRACT: Here, we report the synthesis of Pt/Ag bimetallic alloy catalyst through combining the ion implantation and electrodeposition method. Ag nanoparticles are employed as the seeds for the growth of Pt nanoparticles. Pt/Ag alloy catalyst demonstrates much higher catalytic activity than pure Pt catalyst, which is about three times more active on the basis of equivalent Pt electrochemically active surface area than that of the pure Pt catalyst. The ion implantation of Ag efficiently enhances the catalytic activity of Pt catalyst for formic acid oxidation.Applied Physics A 11/2014; 117(2):809-813. DOI:10.1007/s00339-014-8441-0 · 1.69 Impact Factor
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ABSTRACT: The sensing properties of WO3 nanorods decorated with both Pd and Au nanoparticles toward acetone were examined. AuPd-decorated WO3 nanorods were prepared by immersing the WO3 nanorods in an acetone/(25 mM) HAuCl4/(25 mM) PdCl2 solution followed by UV irradiation and annealing. The WO3 nanorods decorated with Au and Pd nanoparticles exhibited a far stronger response to acetone gas that increased with increasing acetone concentration than the monometal-decorated counterparts. XPS analysis showed that considerable alloy formation has occurred during the annealing process of the Au and Pd nanoparticle-decorated WO3 nanorods. Overall, Au and Pd particle-decoration had a synergistic effect on enhancing the sensitivity of the WO3 nanorod sensor to acetone gas. The underlying mechanism of the enhanced response of the Au/Pd bimetallic particle-decorated WO3 nanorods is also discussed.Sensors and Actuators B Chemical 03/2015; 209:180-185. DOI:10.1016/j.snb.2014.11.106 · 3.84 Impact Factor