Magnetically Recyclable Fe@Pt Core−Shell Nanoparticles and Their Use as Electrocatalysts for Ammonia Borane Oxidation: The Role of Crystallinity of the Core

Abstract

Carbon-supported Fe@Pt core-shell nanoparticle (NP) catalysts with Fe cores in different crystal states have been successfully synthesized by a sequential reduction process. Unexpectedly, in contrast to its crystallized counterpart, iron in the amorphous state exerts a distinct and powerful ability as the core for the Fe@Pt NPs. The resultant NPs are far more active for ammonia borane oxidation (by up to 354%) than the commercial Pt/C catalysts. Furthermore, these NPs combine low cost, long-term stability, and easy recovery functions.

Effect of the structure of Ni nanoparticles on the electrocatalytic activity of Ni@Pd/C for formic acid oxidation

“…Although many studies have been focused on coreeshell structured nanoparticles, employing amorphous metal as a core has been rarely reported [26,29]. Thus, the synthesis of Ni@Pd coreeshell structure catalysts with Ni cores in different crystalline states and comparison of their catalytic activities is of great interest.…”

Nanoporous Gold Catalyst for Direct Ammonia Borane Fuel Cells

“…16,17 High catalytic activity was demonstrated for AB oxidation at magnetically recyclable Fe-Pt core-shell nanoparticles with amorphous Fe cores. 18 It has recently been proposed that if the direct electrochemical oxidation of AB occurs in a fuel cell a more negative potential and greater power can be obtained than indirectly releasing hydrogen as the fuel source. 16,[17][18][19][20][21] The standard-state potential of reaction (2) has been calculated as −1.216 V vs. SHE, which is 0.388 V more negative than the hydrogen electrode in an alkaline medium.…”

Synthesis, structural characterization and magnetic properties of Fe/Pt core-shell nanoparticles

“…This is similar to the reported cases of XRD in core-shell NPs of CoO@Pt [9], Fe@Au [10], and Co@Pt [12], and the complex Fe@Pt nanostructures [14], where XRD lines due to the cores were also 5 not observed. Several reasons for this are possible: First, the exposure of the core to x-rays is blocked, at least partially, by the shell; second, the atomic scattering factors of Pt and Au are about 3 times larger than that of Fe and Co making the Bragg lines from Pt and Au that much more intense; and third, the core may be amorphous as suggested by Zhang et al [23] in their studies on the carbon supported Fe@Pt NPs. Using the widths of the major lines in Fig …”