Toward an active and stable catalyst for
oxygen evolution in acidic media: Ti-stabilized
MnO2
Rasmus Frydendal, a Elisa A. Paoli, a Ib Chorkendorff,a Jan Rossmeisl,b,c,* Ifan E.L. Stephens a,*
a Center for Individual Nanoparticle Functionality, Department of Physics, Building 312, Technical University of
Denmark, DK-2800 Kgs. Lyngby, Denmark
b Center for Atomic-scale Materials Design, Department of Physics, Building 307, Technical University of
Denmark, DK-2800 Kgs. Lyngby, Denmark
c Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, København Ø, Denmark
Keywords: Electrochemistry, Catalysis, Oxygen Evolution, Density Functional Theory, Corrosion
Abstract
Catalysts are required for the oxygen evolution reaction, which are abundant, active and stable in
acid. MnO2 is a promising candidate material for this purpose. However, it dissolves at high
overpotentials. Using first principles calculations, we develop a strategy to mitigate this problem by
decorating under-coordinated surface sites of MnO2 with a stable oxide. TiO2 stands out as the most
promising of the different oxides in the simulations. We experimentally verify this prediction by
testing sputter-deposited thin films of MnO2 and Ti-MnO2. We perform a combination of
electrochemical measurements, quartz crystal microbalance and inductively coupled plasma – mass
spectrometry measurements and X-ray photoelectron spectroscopy. Small amounts of TiO2
incorporated into MnO2 lead to a moderate improvement in stability, with only a small decrease in
activity. This study opens up the possibility of engineering surface properties of catalysts so that
active and abundant non-precious metal oxides can be used in acid electrolytes.