title: An Oxofluoride Catalyst Comprised of Transition Metals and a Metalloid for Application in Water Oxidation.
abstract: The application of the recently discovered oxofluoride solid solution (Cox Ni1-x )3 Sb4 O6 F6 as a catalyst for water oxidation is demonstrated. The phase exhibits a cubic arrangement of the active metal that forms oxo bridges to the metalloid with possible catalytic participation. The Co3 Sb4 O6 F6 compound proved to be capable of catalyzing 2H2 O→O2 +4H(+) +4e(-) at 0.33 V electrochemical and ≤0.39 V chemical overpotential with a TOF of 4.4⋅10(-3) , whereas Ni3 Sb4 O6 F6 needs a higher overpotential. Relatively large crystal cubes (0.3-0.5 mm) are easily synthesized and readily handled as they demonstrate both chemical resistance to wear after repeated in situ tests under experimental conditions, and have a mechanical hardness of 270 V0.1 using Vickers indentation. The combined properties of this compound offer a potential technical advantage for incorporation to a catalytic interface in future sustainable fuel production.
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm (Sweden).
authors.forename: Henrik
authors.initials: H
authors.lastname: Svengren
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm (Sweden).
authors.forename: Shichao
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm (Sweden).
authors.forename: Ioannis
authors.initials: I
authors.lastname: Athanassiadis
authors.affiliation: Department of Organic Chemistry, Stockholm University, 10691 Stockholm (Sweden).
authors.forename: Tanja M
authors.initials: TM
authors.lastname: Laine
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm (Sweden). mats.johnsson@mmk.su.se.
authors.forename: Mats
authors.initials: M
authors.lastname: Johnsson
keywords: cobalt; nickel; oxofluorides; solid solutions; water oxidation catalysts