Facile one-step synthesis of supportless porous AuPtPd nanocrystals as high performance electrocatalyst for glucose oxidation reaction

Abstract

Direct glucose fuel cells (DGFCs) received great interest due to non-toxicity, low cost, and renewability. Herein, we demonstrated the synthesis of novel porous AuPtPd nanocrystals (NCs) via plausible one-pot synthesis route. This was implemented by reduction of the metal precursors with l-ascorbic acid in the presence of polyvinylpyrrolidone (PVP) as a structure-directing agent. TEM (transmission electron microscopy) images of the as-synthesized nanocrystals depicted porous nanodendritic morphology with particle size ranging from 20 to 30 nm. The catalytic performance of AuPtPd NCs was investigated towards glucose oxidation reaction (GOR) in alkaline medium compared to AuPt, PtPd, and Pt/C. The delivered maximum oxidation current density over AuPtPd was 10.1 mA cm−2, which is nearly 1.4, 1.8, and 3.5 times greater than AuPt, PtPd, and Pt/C, respectively. Additionally, the ternary electrocatalyst exhibited higher electrochemical stability compared to binary alloys and Pt/C counterparts. Furthermore, AuPtPd revealed lower Tafel slope for GOR compared to binary alloys and Pt/C which affirm enhanced GOR kinetics. The outstanding catalytic performance of AuPtPd NCs was attributed to the synergistic effect of the alloying elements and the high anti-poisoning effect of Au and Pd metals which facilitates the adsorption of surface hydroxyls (OH)ads on the catalyst active sites and enhances the oxidation kinetics.