Regular Papers
Activation Factors of the Oxygen Reduction Reaction on Pt3Co Alloy Single Crystal Electrode in Diethylmethylammonium Triflate [dema][TfO]
2026 年 94 巻 2 号 p. 027003
詳細
2026 年 94 巻 2 号 p. 027003
Increasing the activity of oxygen reduction reaction (ORR) is an important subject for the development of a fuel cell. Operation temperature of a fuel cell of a heavy-duty vehicle (HDV) is more than 100 °C, and the combination of ionic liquids and Pt alloy catalysts can contribute to the increase of the ORR activity at more than 100 °C. We have studied the ORR activity on single crystal electrodes of Pt3Co in diethylmethylammonium triflate ([dema][TfO]). The activity of the ORR at 0.9 V(RHE) at 120 °C increases as Pt3Co(111) < Pt3Co(110) < Pt3Co(100). This order of the activity completely differs from that in 0.1 M HClO4: Pt3Co(100) < Pt3Co(110) < Pt3Co(111). The activity of Pt3Co(100) in [dema][TfO] at 120 °C was higher than that in 0.1 M HClO4 at 25 °C. The ORR current densities at 0.6 V(RHE) in [dema][TfO] at 120 °C exceed the limiting current densities in 0.1 M HClO4 at 25 °C on all the surfaces. The Arrhenius plots show that the frequency factor depends on the surface structure markedly: Pt3Co(111) ≪ Pt3Co(110) ≪ Pt3Co(100). This result suggests that the difference of the number of active sites contributes to the activity for the ORR on Pt3Co single crystal electrodes.
