Abstract
Multimetal oxyhydroxides have recently been reported that outperform noble metal catalysts for oxygen evolution reaction (OER). In such 3d-metal-based catalysts, the oxidation cycle of 3d metals has been posited to act as the OER thermodynamic-limiting process; however, further tuning of its energetics is challenging due to similarities among the electronic structures of neighbouring 3d metal modulators. Here we report a strategy to reprogram the Fe, Co and Ni oxidation cycles by incorporating high-valence transition-metal modulators X (X = W, Mo, Nb, Ta, Re and MoW). We use in situ and ex situ soft and hard X-ray absorption spectroscopies to characterize the oxidation transition in modulated NiFeX and FeCoX oxyhydroxide catalysts, and conclude that the lower OER overpotential is facilitated by the readier oxidation transition of 3d metals enabled by high-valence modulators. We report an ~17-fold mass activity enhancement compared with that for the OER catalysts widely employed in industrial water-splitting electrolysers. [Figure not available: see fulltext.]
| Original language | English (US) |
|---|---|
| Journal | Nature Catalysis |
| DOIs | |
| State | Published - Oct 19 2020 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-30Acknowledgements: This work was supported by MOST (grant no. 2016YFA0203302), NSFC (grant nos. 21875042, 21634003 and 51573027), STCSM (grant nos. 16JC1400702 and 18QA1400800), SHMEC (grant no. 2017-01-07-00-07-E00062) and Yanchang Petroleum Group. This work was also supported by The Programme for Professor of Eastern Scholar at Shanghai Institutions of Higher Learning. This work was supported by the Ontario Research Fund—Research Excellence Program, NSERC and the CIFAR Bio-Inspired Solar Energy program. This work has also benefited from the use of the SGM beamlines at Canadian Light Source; the 1W1B and 4B9B beamlines at the Beijing Synchrotron Radiation Facility; the BL14W1, BL08U1-A beamline at Shanghai Synchrotron Radiation Facility; and the 44A beamline at Taiwan Photon Source (TPS). Mössbauer spectroscopy measurements were conducted at the Advanced Photon Source, a Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357. We acknowledge the Paul Scherrer Institut, Villigen, Switzerland, for provision of synchrotron radiation beamtime at the beamline SuperXAS of the SLS and would like to thank M. Nachtegaal for assistance. We thank M. García-Melchor and Y. Zhang for discussions on DFT calculations. We thank J. Wu for the assistance with the TEM measurements. We thank R. Wolowiec and D. Kopilovic for their assistance. For computer time, this research used the resources of the Supercomputing Laboratory at KAUST.
