Comparing the CO oxidation on Cu, Ag and Au nanoparticles with the corresponding regular (111) surfaces: a theoretical perspective

OTERO, GUADALUPE SOL; PASCUCCI, BRUNO; ILLAS, FRANCESC; BRANDA, MARÍA MARTA; BELELLI PATRICIA GABRIELA

Granada

Congreso; XXXIX Congreso Internacional de Químicos Teóricos de Expresión Latina (Quitel 2013); 2013

In this work, the reactivity and geometrical properties of Cu19, Ag19 and Au19 nanoparticles and of the corresponding (111) surface has been evaluated with a periodic density functional theory (DFT) based approach using the Vienna Ab-Initio Simulation Package (VASP). The CO + O co-adsorption is more favorable on the Cu and Au nanoparticles than on respective (111) surfaces, as expected, while the co-adsorption energy values are similar for Ag nanoparticle and Ag(111). The site preferred for the CO adsorption on all nanoparticles is on-top of corner atoms. Besides, some stable sites for CO + O co-adsorption are obtained for the Cu(111) and Au(111) surfaces and also for the respective nanoparticles, but, so far, this is not observed on Ag. The energy values for the CO oxidation reaction (CO + O -> CO2) are more exothermic on Cu and Ag nanoparticles than on the corresponding (111) surfaces. Preliminary results indicate that the reaction energy is similar for Au19 and Au(111).