Abstract : Pertinent existing hydrogen technologies for energy storage require unsustainable amounts of scarce platinum group metals. Here, an electrocatalyst comprising high-aspect-ratio platinum nanowires (PtNWs) on single-walled carbon nanotubes (SWNTs) with ultralow Pt content (340 ng Pt cm −2) is employed for hydrogen evolution reaction (HER). A comparable activity (10 mA cm −2 at −18 mV vs. RHE) to that of state-of-the-art Pt/C (38,000 ng Pt cm −2) is reached in acidic aqueous electrolyte. This is attributed to favorable PtNW interaction with SWNTs and PtNW edge-sites which adsorb hydrogen optimally and aid at alleviating repulsive interactions. Moreover, the metallic nature of Pt, morphological effects and enhanced wetting contribute positively. The PtNW/SWNT relevance is emphasized at a proton-exchange-membrane electrolyzer generating stable voltage for more than 2000 h, successfully competing with the state-of-the-art reference but with one tenth of Pt mass loading. Overall, this work presents an unprecedently efficient HER catalyst and opens up avenues for PtNW/SWNT catalyzing other high-impact reactions.
https://hal.umontpellier.fr/hal-02519429
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Soumis le : mardi 17 novembre 2020 - 10:41:20 Dernière modification le : mardi 24 novembre 2020 - 17:03:20
T. Rajala, R. Kronberg, R. Backhouse, M.E.M. Buan, M. Tripathi, et al.. A platinum nanowire electrocatalyst on single-walled carbon nanotubes to drive hydrogen evolution. Applied Catalysis B: Environmental, Elsevier, 2020, 265, pp.118582. ⟨10.1016/j.apcatb.2019.118582⟩. ⟨hal-02519429⟩