Highly active nanoporous Pt-based alloy as anode and cathode catalyst for direct methanol fuel cells

• Multi-component np-alloy can be fabricated by ball-milling and two-step dealloying.
• Np-PtPdAlCu alloy shows ultrafine three-dimensional ligament/channel structure.
• Np-PtPdAlCu alloy shows excellent electrocatalytic performance for DMFCs.

In this paper, we explore nanoporous PtPdAlCu (np-PtPdAlCu) quaternary alloy through ball-milling with the subsequent two-step dealloying strategy. The microstructure and catalytic performance of the np-PtPdAlCu catalyst have been characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electrochemical measurements. The np-PtPdAlCu catalyst exhibits an open bi-continuous interpenetrating ligament/channel structure with a length scale of 2.3 ± 0.5 nm. The np-PtPdAlCu catalyst shows 2 and 3.5 times enhancement in the mass activity and area specific activity towards methanol oxidation at anode respectively, compared to the Johnson Matthey (JM) Pt/C (40 wt.%) catalyst. Moreover, the CO stripping peak of np-PtPdAlCu is 0.49 V (vs. SCE), indicating a 180 mV negative shift in comparison with the Pt/C catalyst (0.67 V vs. SCE). In addition, the np-PtPdAlCu catalyst also shows an enhanced oxygen reduction reaction (ORR) activity at cathode compared to Pt/C. The present study provides a facile and effective route to design high-performance catalysts for direct methanol fuel cells (DMFCs).

Ultrafine nanoporous multiple-component alloy with enhanced performance for DMFCs is fabricated by mechanical alloying and subsequent two-step dealloying.Figure optionsDownload as PowerPoint slide