Scaling-Relation Kinetic Monte Carlo Simulations for CO Oxidation over Dilute Pt@Au Alloys

Catalytic low-temperature CO oxidation continues to be
an important
materials challenge. Technological catalysts are commonly based on
Pd and Pt nanoparticles, which are CO poisoned at low temperatures,
hindering O2 adsorption. Using first-principles-based kinetic
Monte Carlo simulations, we explore dilute Pt@Au nanoalloys as a possibility
to enhance the low-temperature activity by spatially separating CO
and O2 adsorption. CO is on these systems absorbed on Pt
sites, whereas O2 reacts molecularly from Au sites to form
OCOO, which decomposes to CO2 and O. The dilute Pt@Au systems
are found to have a higher activity than pure Au systems in a temperature
range not accessible to Pt-only catalysts. The results show that dilute
Pt@Au alloys in combination with Pt-only catalysts have the potential
for CO oxidation in a wide temperature range.