2 research outputs found
The Influence of Inert Ions on the Reactivity of Manganese Oxides
Inert
ion doping is a possible method to modify electrical conductivity
and catalytic activity of transition-metal oxide electrocatalysts.
Despite the importance of dopants, little is known about the underlying
mechanisms for the change of the system properties. We have performed
density functional theory calculations to investigate the influence
of different valent ions on the O<sub>2</sub> evolution reaction activity
of β-MnO<sub>2</sub> and Mn<sub>2</sub>O<sub>3</sub>. While
Mn<sub>2</sub>O<sub>3</sub> is unaffected by dopants, β-MnO<sub>2</sub> is strongly affected by ions placed in a subsurface position.
Doping does not affect the ion charge at the active site, but instead
it effects the bond character. This is concluded through an analysis
of the density overlap regions indicator and the density of states
showing that the partially covalent nature of the bonds in β-MnO<sub>2</sub> is responsible for the changes in the adsorbate binding energies.
This mechanism is not active in the mostly ionic Mn<sub>2</sub>O<sub>3</sub>. These results highlight the need to explicitly consider
the detailed bonding situation and to go beyond simple charge transfer
considerations when describing doping of transition metal oxide catalysts
The Influence of Inert Ions on the Reactivity of Manganese Oxides
Inert
ion doping is a possible method to modify electrical conductivity
and catalytic activity of transition-metal oxide electrocatalysts.
Despite the importance of dopants, little is known about the underlying
mechanisms for the change of the system properties. We have performed
density functional theory calculations to investigate the influence
of different valent ions on the O<sub>2</sub> evolution reaction activity
of β-MnO<sub>2</sub> and Mn<sub>2</sub>O<sub>3</sub>. While
Mn<sub>2</sub>O<sub>3</sub> is unaffected by dopants, β-MnO<sub>2</sub> is strongly affected by ions placed in a subsurface position.
Doping does not affect the ion charge at the active site, but instead
it effects the bond character. This is concluded through an analysis
of the density overlap regions indicator and the density of states
showing that the partially covalent nature of the bonds in β-MnO<sub>2</sub> is responsible for the changes in the adsorbate binding energies.
This mechanism is not active in the mostly ionic Mn<sub>2</sub>O<sub>3</sub>. These results highlight the need to explicitly consider
the detailed bonding situation and to go beyond simple charge transfer
considerations when describing doping of transition metal oxide catalysts