Glycerol-stabilized NaBH4 reduction at room-temperature for the synthesis of a carbon-supported PtxFe alloy with superior oxygen reduction activity for a microbial fuel cell

•Glycerol is used as an efficient stabilizer and solvent to synthesis PtxFe alloy.•PtxFe alloy is prepared by simple two-step at room temperature;.•Pt3-Fe/C show the best ORR catalytic performance in both acidic and neutral media;.•PtxFe alloy enhanced ORR activity and durability in microbial fuel cells.

Insufficient catalytic activity and durability are the most challenging issues in the commercial deployment of low-temperature fuel cells. In an effort to address these barriers, three carbon-supported PtxFe alloy electrocatalysts with varying Pt:Fe atom ratios (Pt3-Fe/C, Pt2-Fe/C, Pt-Fe/C) were prepared by simple NaBH4 reduction in glycerol at room temperature. All of the prepared PtxFe nanoparticles (NPs) are highly dispersed on a carbon support and show a single-phase face-centered cubic structure with a particle size of approximately 2 nm. The electrocatalytic performances of the synthesized PtxFe alloy catalysts were compared with that of commercial Pt/C by cyclic voltammetry and linear sweep voltammetry; among these NPs, the Pt3-Fe/C catalyst exhibits the highest activity and the best stability for oxygen reduction reaction (ORR) in both acidic and neutral media. As the cathode catalyst, the maximum power density produced from microbial fuel cell with Pt3-Fe/C (1680 ± 15 mW m−2) was 18% higher than that with conventional Pt/C (1422 ± 18 mW m−2), and the stability of Pt3-Fe/C was greatly improved.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide