Facile four-electrode electrolytic synthesis of defective PtPd/graphene with low Pt content for hydrogen evolution reaction and ethanol oxidation reaction.

The fabrication of low-Pt loading and cost-efficient electrocatalysts still remains a challenge. In this work, a defective PtPd alloy with ultralow Pt content loaded on graphene (PtPd/G-40) is prepared by electrolytic synthesis method. During electrolysis, the formation of PtPd precursors and the exfoliation of graphite are achieved at the anode and cathode of the cell, respectively. The as-prepared PtPd/G-40 shows excellent electrocatalytic activity and stability toward hydrogen evolution reaction (HER) and ethanol oxidation reaction (EOR). Its mass activity is 29.7 times (at −100 mV) and 1.5 times higher than that of commercial Pt/C for HER and EOR, respectively. The ligand effect generated by formation of PtPd alloy and strain effect caused by abundant defects optimize the electronic structure of active Pt, which enhances its intrinsic activity and reduces the activation energy for HER and EOR. This facile synthetic approach generates a new type of graphene supporting defective metal alloy nanostructures as potential electrocatalysts for advanced energy conversion applications. [Display omitted] • Defective PtPd alloy with ultralow Pt content is produced by an electrolytic method. • The defective PtPd alloy on graphene shows superior electrocatalytic activity. • The impact of defective alloy on reaction intermediate adsorption is revealed. [ABSTRACT FROM AUTHOR]