Fabrication of a Robust PEM Water Electrolyzer Based on Non‐Noble Metal Cathode Catalyst: [Mo 3 S 13 ] 2− Clusters Anchored to N‐Doped Carbon Nanotubes

Autor: Karl Johann Jakob Mayrhofer, Simon Thiele, Melanie Bühler, Daniel Escalera-López, Chuyen Van Pham, Markus Bierling, Florian Speck, Serhiy Cherevko, Peter Holzapfel
Rok vydání: 2020
Předmět:
Zdroj: Small
Small 16(37), 2003161 (2020). doi:10.1002/smll.202003161
ISSN: 1613-6810
DOI: 10.1002/smll.202003161
Popis: High investment costs and a dependence on noble metal catalysts currently obstruct the large-scale implementation of proton exchange membrane water electrolyzers (PEMWEs) for converting fluctuating green electricity into chemical energy via water splitting. In this context, this work presents a high-performing and stable non-noble metal catalyst for the hydrogen evolution reaction (HER), consisting of [Mo3 S13 ]2- clusters supported on nitrogen doped carbon nanotubes (NCNTs). Strikingly, a significant electrochemically induced activation of the Mo3 S13 -NCNT catalyst at high current densities is observed in full cell configuration, enabling a remarkable current density of 4 A cm-2 at a cell voltage of 2.36 V. To the authors' knowledge, this is the highest reported value to date for a PEMWE full cell using a non-noble metal HER catalyst. Furthermore, only a minor degradation of 83 µV h-1 is observed during a stability test of 100 h constant current at 1 A cm-2 , with a nearly unchanged polarization behavior after the current hold. Catalyst stability and activity are additionally analyzed via online dissolution measurements. X-ray photoelectron spectroscopy examination of the catalyst before and after electrochemical application reveals a correlation between the electrochemical activation occurring via electrodissolution with changes in the molecular structure of the Mo3 S13 -NCNT catalyst.
Databáze: OpenAIRE
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