Multi-component nanoporous platinum-ruthenium-copper-osmium-iridium alloy with enhanced electrocatalytic activity towards methanol oxidation and oxygen reduction
X. Chen, C. Si, Y. Gao, J. Frenzel, J. Sun, G. Eggeler, Z. Zhang.
Journal of Power Sources, 273, 324-332, (2015)
Multi-component nanoporous platinum–ruthenium–copper–osmium–iridium (np-PtRuCuOsIr) electrocatalyst has been facilely fabricated by chemical dealloying of mechanically alloyed AlCuPtRuOsIr precursor. The np-PtRuCuOsIr catalyst exhibits a typical three-dimensional bi-continuous interpenetrating ligament/channel structure with a length scale of ∼2.5 nm. The np-PtRuCuOsIr catalyst reaches a higher level in the mass activity (857.5 mA mgPt−1) and specific activity (3.0 mA cm−2) towards methanol oxidation compared to the commercial PtC catalyst (229.5 mA mgPt−1 and 0.5 mA cm−2 respectively). Moreover, the CO stripping peak of np-PtRuCuOsIr is 0.54 V (vs. SCE), 130 mV negative shift in comparison with the commercial PtC (0.67 V vs. SCE). The half-wave potential of np-PtRuCuOsIr is 0.900 V vs. RHE, 36 mV positive compared with that of the commercial PtC (0.864 V vs. RHE). The np-PtRuCuOsIr catalyst also shows 1.8 and 3.8 times enhancement in the mass and specific activity towards oxygen reduction than the commercial PtC. Moreover, the np-PtRuCuOsIr alloy exhibits superior oxygen reduction activities even after 15 K cycles, indicating its excellent long-term stability. The present np-PtRuCuOsIr can act as a promising candidate for the electrocatalyst in direct methanol fuel cells (DMFCs).