Properties of oxygen sites at the MoO3(010) surface: density functional theory cluster studies and photoemission experiments

A van der Waals Density Functional Study of MoO3 and Its Oxygen Vacancies

“…23 Related theoretical works have looked at lattice distortions, doping and electronic structure effects in MoO 3 and MoO 2 , but the energetics and consequences of oxygen vacancy formation in MoO 3 has not been studied in detail. [24][25][26][27] One reason for this may be the challenges of modelling the layered structure accurately due to weak interactions between the layers, necessitating the use of surface models or artificially constrained lattice parameters. The development of van der Waals exchange correlation functionals in density functional theory (DFT) enables a self-consistent treatment of the dispersive interactions and lately these have proven useful in dealing with the layered structure of MoO 3 .…”

“…The 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 15 energies of 6.8-7.6 eV. 25 However, the lowest energy of formation was reported to be on the O3…”

On the asymmetry in molybdenum–oxygen bonding in the MoO3 structure: ETS–NOCV analysis

“…The ETS-NOCV analysis for Mo-O1, Mo-O2, and Mo-O3 bonds in the Mo 7 2-, and the second comprising the rest of the cluster (with charge 2?). It should be emphasized here that the choice of the fragments is an arbitrary element of the ETS-NOCV approach.…”

“…Among many examples in catalysis, the theoretical investigations on the structural and electronic surface properties and the catalytic reactions of transition-metal oxides, in particular based on vanadium and molybdenum, [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] are especially important as they provided a deep insight into the structure-activity relationship of these compounds, used in a variety of applications.…”

“…The third oxygen type O3 (and O3 0 , O3 00 ) is bound symmetrically to two molybdenum atoms (1.94 Å ) and weakly interacting with the third one of another layer (2.33 Å ). The Mo-O bonding was characterized previously by the electron density-difference maps (deformation density), [10] as well as by the quantumchemical bond-order indices originating from various approaches; [7][8][9][10]25] the electronic properties of the three oxygen sites on the (010) and (100) surfaces were characterized, and the oxygen-vacancy formation energies were determined [7][8][9][10].…”