Journal article

Authors list: Schäfer, H; Chevrier, DM; Küpper, K; Zhang, P; Wollschläger, J; Daum, D; Steinhart, M; Hess, C; Krupp, U; Müller-Buschbaum, K; Stangl, J; Schmidt, M

Publication year: 2016

Pages: 2609-2622

Journal: Energy & Environmental Science

Volume number: 9

Issue number: 8

ISSN: 1754-5692

DOI Link: https://doi.org/10.1039/c6ee01304j

Publisher: Royal Society of Chemistry

Abstract: 
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.

Harvard Citation style: Schäfer, H., Chevrier, D., Küpper, K., Zhang, P., Wollschläger, J., Daum, D., et al. (2016) X20CoCrWMo10-9//Co3O4: a metal-ceramic composite with unique efficiency values for water-splitting in the neutral regime, Energy & Environmental Science, 9(8), pp. 2609-2622. https://doi.org/10.1039/c6ee01304j

APA Citation style: Schäfer, H., Chevrier, D., Küpper, K., Zhang, P., Wollschläger, J., Daum, D., Steinhart, M., Hess, C., Krupp, U., Müller-Buschbaum, K., Stangl, J., & Schmidt, M. (2016). X20CoCrWMo10-9//Co3O4: a metal-ceramic composite with unique efficiency values for water-splitting in the neutral regime. Energy & Environmental Science. 9(8), 2609-2622. https://doi.org/10.1039/c6ee01304j