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An Oxygen-Insensitive Hydrogen Evolution Catalyst Coated by a Molybdenum-Based Layer for Overall Water Splitting |
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| Authors: | Dr Angel T Garcia-Esparza Dr Tatsuya Shinagawa Dr Samy Ould-Chikh Muhammad Qureshi Dr Xuyuan Peng Dr Nini Wei Dr Dalaver H Anjum Dr Alain Clo Dr Tsu-Chien Weng Dr Dennis Nordlund Dr Dimosthenis Sokaras Prof Jun Kubota Prof Kazunari Domen Prof Kazuhiro Takanabe |
| Institution: | 1. KAUST Catalysis Center (KCC) and Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia;2. Advanced Nanofabrication, Imaging and Characterization Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia;3. Research Computing, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900 Saudi Arabia;4. Center for High Pressure Science & Technology Advanced Research, 1690 Cailun Rd, Bldg. #6–408, Pudong, Shanghai, 201203 China;5. Stanford Synchrotron Radiation Lightsource, 2575 Sand Hill Road, Menlo Park, CA, 94025 USA;6. Department of Chemical Engineering, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180 Japan;7. Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 Japan |
| Abstract: | For overall water-splitting systems, it is essential to establish O2-insensitive cathodes that allow cogeneration of H2 and O2. An acid-tolerant electrocatalyst is described, which employs a Mo-coating on a metal surface to achieve selective H2 evolution in the presence of O2. In operando X-ray absorption spectroscopy identified reduced Pt covered with an amorphous molybdenum oxyhydroxide hydrate with a local structural order composed of polyanionic trimeric units of molybdenum(IV). The Mo layer likely hinders O2 gas permeation, impeding contact with active Pt. Photocatalytic overall water splitting proceeded using MoOx/Pt/SrTiO3 with inhibited water formation from H2 and O2, which is the prevailing back reaction on the bare Pt/SrTiO3 photocatalyst. The Mo coating was stable in acidic media for multiple hours of overall water splitting by membraneless electrolysis and photocatalysis. |
| Keywords: | Elektrokatalyse In-operando-XAS Photokatalyse Wasserspaltung Wasserstoffentwicklung |