Tc. Guimaraes et al., Dissociation of N-2 on chromium alloys: A general mechanism for dissociation of diatomic molecules, PHYS REV B, 60(16), 1999, pp. 11789-11794
In this work we use ab initio Hartree-Fock effective core potentials to ana
lyze N-2 dissociation on doped (bimetallic) Cr (110) surfaces described by
Cr4MN2 and Cr3M2N2 (M = Sc, Ti, V, Fe, Co, Ni, Zn, Mg, Ca) clusters in both
perpendicular and inclined configurations. Our results indicate that the i
nclined state is energetically more favorable than the perpendicular config
uration. In comparison with monometallic surfaces, some of the bimetallic s
ystems, such as Cr4ScN2, Cr4TiN2, and Cr3V2N2, are found to have larger N-N
distances, surface-->N-2 charge transfers, higher Fermi energies, and smal
ler N-N stretching frequencies, indicating greater efficiency of these allo
ys for dissociation. The theoretical parameters obtained from these bimetal
lic catalytic systems are interpreted using a general mechanism proposed fo
r dissociation of diatomic molecules on transition metal surfaces. [S0163-1
829(99)02639-9].