Catalytic Activities of Pt–Metal Alloys on Oxygen Reduction Reaction in Fluorohydrogenate Ionic Liquid

Abstract

Oxygen reduction reaction (ORR) rate constants (k) on Pt and Pt-M (M = Fe, Co, Ni) electrodes were evaluated in N-ethyl-N-methylpyrrolidinium fluorohydrogenate (EMPyr(FH) 1.7 F) ionic liquid at 298-333 K. The Pt-Fe electrode exhibited the best catalytic activity in EMPyr(FH) 1.7 F, because of the large surface area of its nanoporous structure after Fe dissolution. X-ray photoelectron spectroscopy and field-emission scanning electron microscopy showed that Co and Ni barely dissolved in EMPyr(FH) 1.7 F. The observed ORR activities of Pt-Co and Pt-Ni alloys were lower than that of Pt in EMPyr(FH) 1.7 F.

Formation of Pt Skin Layer on Ordered and Disordered Pt-Co Alloys and Corrosion Resistance in Sulfuric Acid

“…The chemical shift of the Pt 4f XPS spectra for the Pt-Co alloys shown in Fig. 3 agrees with the literature [46,47]. This was attributed to the electron transfer from Co to Pt at the surfaces induced by the formation of the Pt skin layer.…”

Irreversibly Adsorbed Tri-metallic PtBiPd/C Electrocatalyst for the Efficient Formic Acid Oxidation Reaction

“…Similarly, the peak shift of Bi 4f to a lower binding energy indicated the formation of an alloy structure between Pd and Bi, as shown in Fig. 4(b) [27]. The electrochemical performance was examined by CV.…”

“…Instead, the PtBi/C and PtBiPd/C catalysts exhibited enhanced electrocatalytic activity. As summarized in Tables 4 and 5, the current of direct formic acid oxidation (I d ) increased ~ 8 and 16 folds for the PtBi/C and PtBiPd/ C catalysts compared to that of commercial Pt/C because of the electronic, geometric, and third body effects [20,27], which are higher values than those of previous studies [16,17]. In addition, the higher ratio between I d and the current of indirect formic acid oxidation (I ind ) for the PtBi/C and PtBiPd/C catalysts indicates that the dehydrogenation pathway is dominant with less CO formation on these catalysts.…”