Synthesis of octahedral Pt–Pd alloy nanoparticles for improved catalytic activity and stability in methanol electrooxidation

Abstract

We report Pt-Pd nanoparticles synthesized by means of a polyol process with glycerol as a reducing agent. The Pt-Pd nanoparticles exhibit dominantly exposed {111} facets in octahedral shape with complete alloy formation between Pt and Pd. Furthermore, the octahedral Pt-Pd alloy catalysts show improved catalytic activity and stability in methanol electrooxidation.

Synthesis and Electrocatalytic Performance of Multi-Component Nanoporous PtRuCuW Alloy for Direct Methanol Fuel Cells

“…In addition, less-noble metals dissolution would happen when applying potential cycling to multi-metallic alloys [32,36,37]. For np-PtRuCuW, the CV features are different from the PtC and PtRu catalysts (Figure 3a).…”

“…Moreover, the reduction peak of Pt oxides shifts to a more positive direction compared to the PtC and PtRu catalysts (as highlighted by dotted line in Figure 3a). The characteristics are typical to multi-component alloys [7,27,32,36,37]. Normally, the electrochemically active surface area (ECSA) can be obtained from the equation ECSAPt (m 2 /g) = QH/(2.1 × mPt) by integrating the hydrogen ad/desorption charge and using the value of 2.1 C m −2 for the oxidation of a monolayer of hydrogen on a polycrystalline Pt electrode [35,38] Figure 3b, the specific activity of the np-PtRuCuW is 1.8 mA cm −2 , which is 3.6 and 2.9 times that of the PtC and PtRu catalysts (0.5 and 0.63 mA cm ).…”

“…It has been studied that the electro-oxidation of methanol molecules results in the formation of current peak in the forward scan and the removal of the incompletely oxidized carbonaceous species contributes to the current peak in the reverse scan [39]. Hence, the ratio If/Ib can be used to measure the tolerance to carbonaceous species [4,36,40]. The values for the np-PtRuCuW, PtC and PtRu are 1.29, 0.91 and 1.75, respectively, which indicates the higher CO tolerance of np-PtRuCuW than PtC while shows disadvantage compared to PtRu.…”

Electro-oxidation of ethylene glycol and glycerol at palladium-decorated FeCo@Fe core–shell nanocatalysts for alkaline direct alcohol fuel cells: functionalized MWCNT supports and impact on product selectivity

“…The CV parameters for the electrocatalytic performance for each catalysts are summarised in Table 1. The ratio of the forward anodic peak to the backward peak current density (J f /J b ) relates to the ability of the catalyst to tolerate carbonaceous species, 47,50,51 thus it should generally be a higher value for the best-performing catalyst. The onset potential (E onset ) and peak potential for the forward reaction (E peak ) describe the ease at which electro-oxidation occurs at the catalyst, thus they should be less positive for the best-performing electrocatalysts.…”

Correlation between composition and structure of PtxNiyalloy nanodendrites

“…In particular, shape-controlled metallic NPs have been synthesized with 0-dimensional (cube, octahedron, truncated cube, and tetrahedron) [6][7][8][9][10], 1-dimensional (wire, rod, and tube) [11][12][13], 2-dimensional (plate and sheet), and 3-dimensional (star, flower, and dendrite) structures [14][15][16][17]. Among them, the dendritic and flower-like nanostructures for electrochemical energy conversion devices such as fuel cells and metal-air batteries have shown much enhanced electrocatalytic activity and stability [18].…”