Density functional theory study of MnO2, TiO2 and VO2

Abstract

We investigate the structural stability of metal oxides β-MnO2, TiO2 and VO2 (MO2) which are used as catalyst in metal air batteries, using the density functional theory (DFT) within the generalized gradient approximation (GGA). Their mechanical property was determined to show the stability trend of the metal oxides catalyst. Cell parameters of the bulk structures of the MO2 are in reasonable agreement with the experimental values (deviations of approximately 0.8% and -3.1% for a and c, respectively, and of 1.6 % in the cell volume). Phonon dispersion curves show that rutile (R) TiO2 is the most stable structure since it does not have vibrations in the negative frequencies.