title: Insights into the mechanism of electrochemical ozone production via water splitting on the Ni and Sb doped SnO2catalyst.
abstract: The H2O splitting mechanism is a very attractive alternative used in electrochemistry for the formation of O3. The most efficient catalysts employed for this reaction at room temperature are SnO2-based, in particular the Ni/Sb-SnO2catalyst. In order to investigate the H2O splitting mechanism density functional theory (DFT) was performed on a Ni/Sb-SnO2surface with oxygen vacancies. By calculating different SnO2facets, the (110) facet was deemed most stable, and further doped with Sb and Ni. On this surface, the H2O splitting mechanism was modelled paying particular attention to the final two steps, the formation of O2and O3. Previous studies on β-PbO2have shown that the final step in the reaction (the formation of O3) occurs via an Eley-Rideal style interaction where surface O2desorbs before attacking surface O to form O3. It is revealed that for Ni/Sb-SnO2, although the overall reaction is the same the surface mechanism is different. The formation of O3is found to occur through a Langmuir-Hinshelwood mechanism as opposed to the Eley-Rideal mechanism. In addition to this the relevant adsorption energies (Eads), Gibb's free energy (ΔGrxn) and activation barriers (Eact) for the final two steps modelled in the gas phase have been shown, providing the basis for a tool to develop new materials with higher current efficiencies.
authors.affiliation: Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK. w.lin@lboro.ac.uk and School of Chemistry and Chemical Engineering, Queen's University of Belfast, Belfast, BT9 5AG, UK.
authors.forename: Gregory
authors.initials: G
authors.lastname: Gibson
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Ziyun
authors.identifier: http://orcid.org/0000-0002-2817-8367
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, M13 9PL, UK.
authors.forename: Christopher
authors.identifier: http://orcid.org/0000-0001-7256-6765
authors.initials: C
authors.lastname: Hardacre
authors.affiliation: Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK. w.lin@lboro.ac.uk.
authors.forename: Wen-Feng
authors.identifier: http://orcid.org/0000-0002-4256-2058
authors.initials: WF
authors.lastname: Lin