Mixing thermodynamics and electronic structure of the Pt_1−xNi_x(0 ≤x≤ 1) bimetallic alloy

Abstract

Density functional theory simulations complemented by force-field based calculations show that the bimetallic Pt0.5Ni0.5 equilibrium composition is highly ordered at room conditions.

Tailoring the selectivity of ultralow-power heterojunction gas sensors by noble metal nanoparticle functionalization

“…We have used the Vienna Ab initio Simulation Package (VASP) [30][31][32][33] [34,35]. Long-range dispersion interactions were included using the semi-empirical method of Grimme, with the Becke-Johnson damping [D3-(BJ)] [36,37], which is required for the realistic simulation of the bulk and surface properties of several different materials [9,[38][39][40][41][42][43][44][45]. The inner electron included up to the 3s level for Cu; 2p level for Ti; 4f level for Pt; 4s level for Pd and Ag; and 1s level for O, C and N, and were described by the projector augmented wave (PAW) method [46,47], whereas the electron of the H atom was treated as valence.…”

The role of surface oxidation and Fe–Ni synergy in Fe–Ni–S catalysts for CO2 hydrogenation

“…Longrange dispersion interactions were applied using the D2 semi-empirical method of Grimme, 43 which is needed to describe properly the bulk and surface properties of different materials. 31,[44][45][46][47][48][49][50][51][52] The Kohn-Sham valence states were expanded in a periodic plane-wave basis set with a cut-off fixed at 400 eV for the kinetic energy. The optimisation of the electronic density was considered converged when the energy difference between two consecutive self-consistent loop steps was below 10 −5 eV.…”

Thermodynamics of the Atomic Distribution in Pt3Pd2, Pt2Pd3 and their Corresponding (111) Surfaces

“…Various bulk configurations, at the desired ratios of Pt 3 Pd 2 and Pt 2 Pd 3 , were constructed by substitution of Pd into all available sites of the pure Pt bulk and vice versa, using the program Site-Occupation Disorder (SOD) 11 in a similar manner to the recent study conducted by Botha et al 12 The unit cells of Pt and Pd were constructed with F-type lattice, in a face-centred cubic (fcc) cell with space group Fm-3m (number 225) by entering the crystallographic properties into SOD. The cell size was limited to a 2 × 2 × 1 supercell as larger supercells were unfeasible due to the large numbers of configurations generated for the different alloy compositions that would need to be considered, which would be beyond the computational capabilities of the SOD program.…”