Efficient Electrochemical Oxygen Reduction to Hydrogen Peroxide by Transition Metal-Doped Silicate Sr0.7Na0.3SiO3−δ
- 27 December 2020
- journal article
- research article
- Published by American Chemical Society (ACS) in ACS Applied Materials & Interfaces
- Vol. 13 (1), 382-390
- https://doi.org/10.1021/acsami.0c16311
Abstract
Electrochemical oxygen reduction in a selective two-electron pathway is an efficient method for onsite production of H2O2. State of the art noble metal-based catalysts will be prohibitive for widespread applications, and hence earth-abundant oxide-based systems are most desired. Here we report transition metal (Mn, Fe, Ni, Cu)-doped silicates, Sr0.7Na0.3SiO3−δ, as potential electrocatalysts for oxygen reduction to H2O2 in alkaline conditions. These novel compounds are isostructural with the parent Sr0.7Na0.3SiO3−δ and crystallize in monoclinic structure with corner-shared SiO4 groups forming cyclic trimers. The presence of Na stabilizes O vacancies created on doping, and the transition metal ions provide catalytically active sites. Electrochemical parameters estimated from Tafel and Koutechy–Levich plots suggest a two-electron transfer mechanism, indicating peroxide formation. This is confirmed by the rotating ring disc electrode method, and peroxide selectivity and Faradaic efficiency are calculated to be in the range of 65–82% and 50–68%, respectively, in a potential window 0.3 to 0.6 V (vs RHE). Of all the dopants, Ni imparts the maximum selectivity and efficiency as well as highest rate of formation of H2O2 at 1.65 μmol s–1.Keywords
Funding Information
- Department of Science and Technology, Ministry of Science and Technology
This publication has 54 references indexed in Scilit:
- Number of outer electrons as descriptor for adsorption processes on transition metals and their oxidesChemical Science, 2013
- Low content cerium oxide nanoparticles on carbon for hydrogen peroxide electrosynthesisApplied Catalysis A: General, 2011
- Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and NiApplied Surface Science, 2010
- Defect chemistry and oxygen ion migration in the apatite-type materials La9.33Si6O26 and La8Sr2Si6O26Journal of Materials Chemistry, 2003
- ELECTRONIC STRUCTURE AND CATALYSIS ON METAL SURFACESAnnual Review of Physical Chemistry, 2002
- H2O2 in CO2/H2O Biphasic Systems: Green Synthesis and Epoxidation ReactionsIndustrial & Engineering Chemistry Research, 2002
- Oxygen reduction at polypyrrole electrodes—I. Theory and evaluation of the rrde experimentsElectrochimica Acta, 1985
- Electrocatalysts for O2 reductionElectrochimica Acta, 1984
- Recent Advances in the Science of ElectrocatalysisJournal of the Electrochemical Society, 1981
- Kinetic studies of the oxygen—peroxide couple on pyrolytic graphiteElectrochimica Acta, 1970