Surface Oxygen-Mediated Ultrathin PtRuM (Ni, Fe and Co) Nanowires Boosting Methanol Oxidation Reaction
Improving the electrocatalytic activity and durability of electrocatalysts is of vital importance to the direct methanol fuel cells. PtRu materials are the most effective catalysts for methanol oxidation reaction (MOR) in acidic medium, but it still exhibits partial defects, such as limited catalytic activity. Here we prepared a series of surface oxygen-mediated ultrathin PtRuM (M = Ni, Fe, and Co) nanowires (NWs), termed PtRuM-O. All these prepared materials show ultrahigh electrocatalytic activity and excellent durability for MOR in acidic medium due to the optimal electronic structures induced by the introduction of electroactive O. Until now, in the reported Pt-based materials article (Table S1), the optimal Pt62Ru18Ni20-O/C electrocatalyst shows the highest mass activity of 2.72 A mg−1pt for MOR in the acidic medium, which is 1.42, 5.14 and 9 times higher than that of Pt62Ru18Ni20/C (1.91 A mg−1pt), Pt65Ru35/C (0.47 A mg−1pt) and Pt/C (0.30 A mg−1pt) NWs catalysts, respectively. And the Pt62Ru18Ni20-O/C catalyst still retains 92% of initial mass activity after 1000 cyclic voltammetry (CV). The CO stripping experiment results reveal that the peak potential of Pt62Ru18Ni20-O/C show a negative shift compare with Pt62Ru18Ni20/C, Pt65Ru35/C, and Pt/C NWs catalysts, indicating that the Pt62Ru18Ni20-O/C catalyst has the best CO anti-poisoning. The prepared electrocatalysts also show better MOR performance in the alkaline medium. Density functional theory (DFT) calculations prove that the introduction of O to PtRuNi significantly boosts the MOR performance by strengthening the adsorption of initial CH3OH induced by the electroactive O-2p bands. Meanwhile, the much larger energy barrier for CO generation indicates the much lower probability of catalyst poisoning of the PtRuNi-O.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers