High‐Quality Platinum–Iron Nanodendrites with a Multibranched Architecture as Efficient Electrocatalysts for the Ethanol Oxidation Reaction

Abstract

Although great success has been made in the design of well‐defined nanocrystals (NCs) with various morphologies, a facile method to prepare desirable NCs with large active surface areas and unique facets remains an arduous challenge. Herein, we demonstrate a facile method for the successful synthesis of high‐quality PtFe nanodendrites with a multibranched architecture; these nanodendrites have an abundance of exposed surface active sites that are available for ethanol molecules. Detailed study of its electrocatalytic properties revealed that the resultant superbranched PtFe nanocatalysts displayed superior electrocatalytic activity towards ethanol oxidation with unprecedentedly high mass/specific activities of 3692.5 mA mg−1 and 7.02 mA cm−2; these values are 9.3 and 10.0‐fold higher than those of a commercial Pt/C catalyst, signifying that the these nanodendrites may serve as highly efficient catalysts for fuel cells and beyond.

Addition of CeO2 Nanorods in PtSn-Based Electrocatalysts for Ethanol Electrochemical Oxidation in Acid Medium

“…Figure 1 shows the XRD for Pt 3 Sn 1 /C, Pt 2 Sn 1 /C, Pt 1 Sn 1 /C and Pt/C in which the platinum crystallographic peak patterns are evident in 2θ: 39º (111); 46º (200) and 68º (220), respectively. 8,14,36,37 These peaks do not show shifts in their values for 2θ removed in the materials PtSn/C, identifying the nonformation of alloy between the two metals, which would imply a shift in the diffraction angle for smaller values and changes in the lattice parameter. 26,27 The XRD analyzes were used to determine the network parameter based on the principles of Bragg's law in which the interplanar distance is determined, 4,38 as shown in equation 1, and were subsequently applied in the lattice parameter formula.…”

“…9,10 CO is responsible for promoting catalytic poisoning, 11,12 a situation in which it occupies the active sites for Pt hindering interactions with organic molecules of interest, and forms with significant quantity via known synthesis, routes for ethanol oxidation processes. 10,13,14 For this reason, it is important to understand such mechanisms and to develop catalysts capable of diminishing their formation during the processes of electrocatalysis. 3 The electronic effect of Pt-Sn type electrocatalysts is not only due to the unique contribution of Sn, but also due to the bifunctional mechanism.…”

Facile Synthesis of Pt Icosahedral Nanocrystals with Controllable Sizes for the Evaluation of Size‐Dependent Activity toward Oxygen Reduction

“…Platinum nanocrystals have received tremendous attention owing to their extensive use in an array of applications related to catalysis, electrocatalysis, and energy conversion . In the context of catalysis or electrocatalysis, both the activity and selectivity of Pt nanocrystals are strongly dependent on their surface structures as the exposed facets essentially define the nature of active sites and thus the energetics of a catalytic reaction …”

“…Platinum nanocrystals have received tremendous attention owing to their extensive use in an array of applications related to catalysis, electrocatalysis, and energy conversion. [1][2][3][4][5][6][7] In the context of catalysis or electrocatalysis, both the activity and selectivity of Pt nanocrystals are strongly dependent on their surface structures as the exposed facets essentially define the nature of active sites and thus the energetics of a catalytic reaction. [8À 10] A notable example can be found in Pt{100} and Pt {111} facets, where the Pt{111} facets have been demonstrated to be five times more active than Pt{100} facets toward oxygen reduction, a reaction central to the operation of protonexchange membrane fuel cells.…”

Facile Synthesis of Sea-Urchin-Like Pt and Pt/Au Nanodendrites and Their Enhanced Electrocatalytic Properties

“…Noble metals, in particular Pt, are excellent catalysts in many important fields, such as in fuel cells and fine chemical synthesis, because of their unique ability to facilitate both oxidation and reduction reactions. − Given the high demand and price for Pt, it is necessary to reduce the amount of Pt used in specific applications by increasing its catalytic efficiency and selectivity. , To this end, morphological control of nanoparticles has been extensively pursued because it is generally accepted that the size and shape of Pt nanomaterials determine their surface area and exposed crystalline facets, and consequently their catalytic reactivity and selectivity. , Earlier studies focused mainly on zero-dimensional Pt nanocrystals, one-dimensional Pt nanowires and nanotubes, which possess high surface energy and easily changeable morphology as a result of Ostwald ripening and grain growth under the harsh conditions during the fuel cell operation . Moreover, corrosion of the carbon support and subsequent catalyst detachment, dissolution, and aggregation can further deteriorate the catalyst durability …”