title: The oxygen reduction reaction at the three-phase boundary: nanoelectrodes modified with Ag nanoclusters.
abstract: Silver nanoclusters are deposited on bifunctional Θ-shaped nanoelectrodes consisting of a carbon nanoelectrode combined with a hollow nanopipette. The Θ-nanoelectrodes are used as model systems to study interfacial mass transport in gas diffusion electrodes and in particular oxygen-depolarized cathodes (ODC) for the oxygen reduction reaction (ORR) in chlor-alkali electrolysers. By local delivery of O2gas to the electroactive Ag nanoclusters through the adjacent nanopipette, enhanced currents for the ORR at the Ag nanoparticles are recorded which are not accountable when considering the low solubility and slow diffusion of O2in highly alkaline media. Instead, local oversaturation of O2leads to current enhancement at the Ag nanoclusters. Due to the intrinsic high mass transport rates at the nanometric electrodes accompanied by local delivery of reactants, the method generally allows to study electrochemical reactions at single nanoparticles beyond the limitations induced by slow diffusion and low reactant concentration. Kinetic and mechanistic information, for instance derived from Tafel slopes, can be obtained from kinetic regimes not accessible to standard techniques.
authors.affiliation: Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany. jan.clausmeyer@rub.de wolfgang.schuhmann@rub.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Clausmeyer
authors.affiliation: Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany. jan.clausmeyer@rub.de wolfgang.schuhmann@rub.de.
authors.forename: Alexander
authors.identifier: 0000-0003-3321-7014
authors.initials: A
authors.lastname: Botz
authors.affiliation: Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany. jan.clausmeyer@rub.de wolfgang.schuhmann@rub.de.
authors.forename: Denis
authors.initials: D
authors.lastname: Öhl
authors.affiliation: Analytical Chemistry - Center for Electrochemical Sciences (CES), Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780, Bochum, Germany. jan.clausmeyer@rub.de wolfgang.schuhmann@rub.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schuhmann