Simple fabrication of core-shell AuPt@Pt nanocrystals supported on reduced graphene oxide for ethylene glycol oxidation and hydrogen evolution reactions

Herein, we reported the direct synthesis of core-shell AuPt@Pt nanocrystals supported on reduced graphene oxide (AuPt@Pt NCs/rGO) in aqueous media, with poly(1-vinyl-3-ethylimidazolium bromide) (poly(ViEtlmBr)) as a structure-directing agent, without any specific additive (e.g., seed, organic solvent or template). The as-synthesized AuPt@Pt NCs/rGO exhibited improved electrocatalytic performances towards ethylene glycol oxidation reaction (EGOR) in contrast with commercial Pt/C (20%) catalyst in acidic and alkaline electrolytes. Meanwhile, the catalyst displayed enhanced catalytic activity for hydrogen evolution reaction (HER) with the positive onset potential (-25 mV) and a small Tafel slope (33 mV decade(-1)) relative to Pt/C catalyst (-18 mV, 31 mV decade(-1)) in 0.5 M H2SO4, along with the positive onset potential (-43 mV) and a small Tafel slope (73 mV decade(-1)) as compared with Pt/C catalyst (-42 mV, 85 mV decade(-1)) in 0.5 M KOH. (C) 2016 Elsevier Ltd. All rights reserved.