Oxidising CO to CO2 using ceria nanoparticles.

We calculate, using simulated amorphisation and recrystallisation (A&R), that ceria (CeO2) nanoparticles, about 8 nm in diameter, comprise a high concentration of labile surface oxygen species, which we suggest will help promote the oxidation of CO to CO2. In particular, the ceria nanoparticle contains a high proportion of reactive {100} surfaces, surface steps and corner sites. When reduced to CeO1.95, the associated Ce3+ species and oxygen vacancies decorate step, corner and {100} sites in addition to plateau positions on {111}. The energetics of CO oxidation to CO2, catalysed by a ceria nanoparticle, is calculated to be lower compared with CO oxidation associated with the lowest energy surface (i.e. CeO2(111)) of the corresponding 'bulk' material. Our calculated morphologies for the ceria nanoparticles are in accord with experiment.