X20CoCrWMo10-9//Co3O4: a metal-ceramic composite with unique efficiency values for water-splitting in the neutral regime
Autor(en): | Schaefer, Helmut Chevrier, Daniel M. Kuepper, Karsten Zhang, Peng Wollschlaeger, Joachim Daum, Diemo Steinhart, Martin Hess, Claudia Krupp, Ulrich Mueller-Buschbaum, Klaus Stangl, Johannes Schmidt, Mercedes |
Stichwörter: | CHALLENGES; Chemistry; Chemistry, Multidisciplinary; CO3O4 NANOCRYSTALS; COBALT OXIDE; ELECTROCATALYTIC OXYGEN EVOLUTION; Energy & Fuels; Engineering; Engineering, Chemical; Environmental Sciences; Environmental Sciences & Ecology; EVOLVING CATALYST; IRON ELECTRODES; MORPHOLOGY; OXIDATION; PERFORMANCE; STAINLESS-STEEL | Erscheinungsdatum: | 2016 | Herausgeber: | ROYAL SOC CHEMISTRY | Journal: | ENERGY & ENVIRONMENTAL SCIENCE | Volumen: | 9 | Ausgabe: | 8 | Startseite: | 2609 | Seitenende: | 2622 | Zusammenfassung: | Water splitting allows the storage of solar energy into chemical bonds (H-2 O-2) and will help to implement the urgently needed replacement of limited available fossil fuels. In particular, in a neutral environment electrochemically initiated water splitting suffers from low efficiency due to high overpotentials (eta) caused by the anode. Electro-activation of X20CoCrWMo10-9, a Co-based tool steel resulted in a new composite material (X20CoCrWMo10-9//Co3O4) that catalyzes the anode half-cell reaction of water electrolysis with a so far, unequalled effectiveness. The current density achieved with this new anode in pH 7 corrected 0.1 M phosphate buffer is over a wide range of eta around 10 times higher compared to recently developed, up-to-date electrocatalysts and represents the benchmark performance which advanced catalysts show in regimes that support water splitting significantly better than pH 7 medium. X20CoCrWMo10-9//Co3O4 exhibited electrocatalytic properties not only at pH 7, but also at pH 13, which are much superior to the ones of IrO2-RuO2, single-phase Co3O4- or Fe/Ni-based catalysts. Both XPS and FT-IR experiments unmasked Co3O4 as the dominating compound on the surface of the X20CoCrWMo10-9//Co3O4 composite. By performing a comprehensive dual beam FIB-SEM (focused ion beam-scanning electron microscopy) study, we could show that the new composite does not exhibit a classical substrate-layer structure due to the intrinsic formation of the Co-enriched outer zone. This structural particularity is basically responsible for the outstanding electrocatalytic OER performance. |
ISSN: | 17545692 | DOI: | 10.1039/c6ee01304j |
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geprüft am 19.05.2024