First-principles density functional theory (DFT) calculations were carried out to investigate the structural and electronic properties of beryllium (Be) doped and, Be with boron (B) co-doped graphene systems.

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Density functional theory calculations were performed to examine the formation of oxygen atom vacancies on three model surfaces namely, clean anatase TiO2(001) and, Au3 and Au10 clusters supported on anatase TiO2(001). On the Au/TiO2 systems, three different types of lattice oxygen atoms can be identified: the Ti-O-Au bridge, the Ti-O-Ti bridge in the perimeter of the Au cluster and the Ti-O-Ti bridge away from the Au cluster, the oxygen atoms on the clean surface. The variation in ΔG° with temperature for surface O vacancy formation was calculated for these three situations using total-energy, vibrational structure and optimized geometries of the material surfaces and the O2 molecule. The calculations reveal that the O defect formation on the clean anatase TiO2(001) surface seems very difficult due to the large positive value of ΔG° (290 kJ mol(-1)) from 0 to 650 K. However, the presence of the Au cluster on the TiO2 surface changes the surface chemistry of the TiO2 significantly. We observed that the trend in ΔG° variation for the vacancy formation from the Ti-O-Au bridge is the same as on Au3/TiO2 and Au10/TiO2 systems, almost constant with large positive values of ΔG° around 250 and 350 kJ mol(-1), respectively. The ΔG° for the perimeter defect formation (Ti-O-Ti bridge in the perimeter of the Au cluster) is smaller for Aun/TiO2 systems than the clean TiO2 surface, however, the vacancy formation is possible only for the Au10/TiO2 system (close to 506 K). Finally, extended calculations for other oxygen atoms on the Au10/TiO2 model reveal that the trend in ΔG° variation is similar for all the interface or perimeter O atoms around the Au cluster with marginal differences in the numerical value of ΔG°. Since, the surface O atoms are activated only in the presence of a particular sized Au, we propose that a Au catalyzed Mars-van Krevelen mechanism could be a possible reaction mechanism for CO oxidation on Au/TiO2 catalysts at slightly elevated temperatures.

Density functional theory calculations were performed to model a reaction relevant bimetallic surface and study the water gas shift reaction.

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Active oxygen for CO oxidation over Au/TiO2 is a highly stable atomic species, which is formed at the perimeter of the Au/oxide interface.

The water‐gas‐shift reaction (WGSR) is an important industrial process that can be significantly enhanced at suitable catalyst surfaces. In this work, we investigate the catalytic behavior of metallic Cu(1 0 0) and bimetallic Cu–Au(1 0 0) surfaces. With density functional theory calculations, the variation in the Gibbs free energy (ΔG°), the activation barriers, and the rate constants for the WGSR are calculated. The variation in ΔG° for water dissociation shows that the process is spontaneous up to 520 K on the bimetallic surface and up to 229 K on the Cu(1 0 0) surface. The calculated rate constants for the process also show that the bimetallic surface is much more reactive than the Cu(1 0 0) surface. The calculated pressure–temperature phase diagram for water dissociation shows that the partial pressure of H2O required for water dissociation on the bimetallic surface is substantially lower than that on the Cu(1 0 0) surface at all the studied temperatures. Additionally, the calculations demonstrate that the kinetics of the water‐gas‐shift reaction is dominated by redox processes on both the surfaces.

The non-planar molecular doping of BeO is more efficient in inducing a band gap relative to its planar doping with no magnetic effect realization.