Fabrication of a Robust PEM Water Electrolyzer Based on Non‐Noble Metal Cathode Catalyst: [Mo3S13]2− Clusters Anchored to N‐Doped Carbon Nanotubes

Language
en
Document Type
Article
Issue Date
2020-12-29
First published
2020-09-17
Issue Year
2020
Authors
Holzapfel, Peter K. R.
Bühler, Melanie
Escalera‐López, Daniel
Bierling, Markus
Speck, Florian D.
Mayrhofer, Karl J. J.
Cherevko, Serhiy
Pham, Chuyen V.
Thiele, Simon
Editor
Publisher
Wiley‐VCH GmbH
Abstract

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 [Mo3S13]2− clusters supported on nitrogen doped carbon nanotubes (NCNTs). Strikingly, a significant electrochemically induced activation of the Mo3S13‐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 Mo3S13‐NCNT catalyst.

Journal Title
Small
Volume
16
Issue
37
Citation
Small 16.37 (2020). <https://onlinelibrary.wiley.com/doi/10.1002/smll.202003161>