A Comprehensive Search
for Stable Pt–Pd Nanoalloy
Configurations and Their Use as Tunable Catalysts
- Publication date
- Publisher
Abstract
Using density-functional theory, we predict stable alloy
configurations
(ground states) for a 1 nm Pt–Pd cuboctahedral nanoparticle
across the entire composition range and demonstrate their use as tunable
alloy catalysts via hydrogen-adsorption studies. Unlike previous works,
we use simulated annealing with a cluster expansion Hamiltonian to
perform a rapid and comprehensive search that encompasses both high
and low-symmetry configurations. The ground states show Pt(core)–Pd(shell)
type configurations across all compositions but with specific Pd patterns.
For catalysis studies at room temperatures, the ground states are
more realistic structural models than the commonly assumed random
alloy configurations. Using the ground states, we reveal that the
hydrogen adsorption energy increases (decreases) monotonically with
at. % Pt for the {111} hollow ({100} bridge) adsorption site. Such
trends are useful for designing tunable Pd–Pt nanocatalysts
for the hydrogen evolution reaction