Facing seawater splitting challenges by regeneration with Ni−Mo−Fe bifunctional electrocatalyst for hydrogen and oxygen evolution
Ros, Carles (Institut de Recerca en Energia de Catalunya)
Murcia López, Sebastián (Institut de Recerca en Energia de Catalunya)
Garcia, Xènia (Universitat Politècnica de Catalunya. Departament d'Enginyeria Química)
Rosado, Marcos (Institut Català de Nanociència i Nanotecnologia)
Arbiol i Cobos, Jordi (Institut Català de Nanociència i Nanotecnologia)
Llorca, Jordi (Universitat Politècnica de Catalunya. Departament d'Enginyeria Química)
Morante, Joan Ramon (Institut de Recerca en Energia de Catalunya)

Fecha:	2021
Resumen:	Hydrogen, produced by water splitting, has been proposed as one of the main green energy vectors of the future if produced from renewable energy sources. However, to substitute fossil fuels, large amounts of pure water are necessary, scarce in many world regions. In this work, we fabricate efficient and earth-abundant electrodes, study the challenges of using real seawater, and propose an electrode regeneration method to face undesired salt deposition. Ni−Mo−Fe trimetallic electrocatalyst is deposited on non-expensive graphitic carbon felts both for hydrogen (HER) and oxygen evolution reactions (OER) in seawater and alkaline seawater. Cl pitting and the chlorine oxidation reaction are suppressed on these substrates and alkalinized electrolyte. Precipitations on the electrodes, mainly CaCO, originating from seawater-dissolved components have been studied, and a simple regeneration technique is proposed to rapidly dissolve undesired deposited CaCO in acidified seawater. Under alkaline conditions, Ni−Mo−Fe-based catalyst is found to reconfigure, under cathodic bias, into Ni−Mo−Fe alloy with a cubic crystalline structure and Ni : Fe(OH) redeposits whereas, under anodic bias, it is transformed into a follicular Ni:FeOOH structure. High productivities over 300 mA cm and voltages down to 1. 59 V@10 mA cm for the overall water splitting reaction have been shown, and electrodes are found stable for over 24 h without decay in alkaline seawater conditions and with energy efficiency higher than 61. 5 % which makes seawater splitting promising and economically feasible.
Ayudas:	Ministerio de Ciencia e Innovación RTI2018-093996-B Ministerio de Economía y Competitividad ENE2017-85087-C3 Ministerio de Economía y Competitividad SEV-2017-0706 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-128 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1246
Nota:	Altres ajuts: ICN2 is funded by the CERCA Programme/Generalitat de Catalunya. X.G. is grateful to Generalitat de Catalunya for PhD grant 2017 FI_B 00137. JL is a Serra Húnter fellow and is grateful to ICREA Academia program.
Derechos:	Tots els drets reservats.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió acceptada per publicar
Materia:	Alloys ; Degradation ; Regeneration ; Seawater ; Watersplitting
Publicado en:	ChemSusChem, Vol. 14, issue 14 (July 2021) , p. 2872-2881, ISSN 1864-564X

DOI: 10.1002/cssc.202100194

Postprint 39 p, 2.2 MB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Nanociència i Nanotecnologia (ICN2)
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