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O: Fachverband Oberflächenphysik
O 94: Oxides and insulators: Adsorption and reaction of small molecules
O 94.7: Vortrag
Freitag, 13. März 2026, 11:15–11:30, HSZ/0204
Tailoring the OER activity of Co3O4 surfaces by Mn and V-doping: insights from DFT+U calculations — •Palani Muthu Kumar and Rossitza Pentcheva — Department of Physics, University of Duisburg-Essen
The rational design of efficient electrocatalysts for sustainable energy conversion demands an atomistic understanding of how surface modifications influence the overall activity. Here we present a detailed DFT+U investigation of Mn- and V-doping on the oxygen evolution reaction (OER) activity at Co3O4 surfaces. Mn-doping at the surface octahedral sites on both A- and B-terminated Co3O4(001), reduces the OER activity. Conversely, V-doping demonstrates termination-dependent behaviour: at the B-termination, V5+ in a surface octahedral site reduces the overpotential at Cooct from 0.48 V to 0.43 V. At the A-termination, V4+ in a subsurface octahedral site leads to the lowest overpotential of 0.18 V at Cotet reaction site, reversing the intrinsic activity trend where pristine Cotet sites (0.74 V) are less active than Cooct2 (0.55 V) sites. For most studied cases, the deprotonation of *OH to *O is the potential-determining step. The enhanced catalytic activity of the V-doped A-termination originates from the modification of surface Co3+(IS) to Co2+, weakening the *OH binding energy and lowering the PDS by 0.56 eV. These findings show that selective doping effectively tunes electrocatalyst performance. The scope of the investigation is further extended to the Co3O4(111) surface, thereby broadening the understanding of facet-dependent effects.
Keywords: density functional theory; oxygen evolution reaction; water splitting; cobalt oxide; spinel surfaces