Thermodynamic modeling of the Pd–Zn system with uncertainty quantification and its implication to tailor catalysts

Pd–Zn intermetallic catalysts show encouraging combinations of activity and selectivity on well-defined active site ensembles. Thermodynamic description the system, delineating phase boundaries enumerating occupancies within intermediate alloy phases, is essential to determining ensembles atoms as a function composition temperature. Combining present extensive first-principles calculations based density functional theory (DFT) available experimental data, system was remodeled using CALculation PHAse Diagrams (CALPHAD) approach. High throughput modeling tools with uncertainty quantification, i.e., ESPEI PyCalphad, were incorporated in analysis. The across ? region given special attention. A four-sublattice model used for owing its four Wyckoff positions, outer tetrahedral (OT) 8c, inner (IT) octahedral (OH) 12e, cuboctahedral (CO) 24g. fractions Pd Zn calculated from thermodynamic occupancy preference OT OH sublattices agreement observations. force constants obtained DFT-based phonon further supports tendency occupying sublattice compared IT CO sublattice. catalytic changing monomers (Pd1) trimers (Pd3) surface are attributed increase