Theoretical Calculations on the Oxidation of CO on Au₅₅, Ag₁₃Au₄₂, Au₁₃Ag₄₂, and Ag₅₅ Clusters of Nanometer Size

Abstract

Using density-functional theory (DFT), we investigated the oxidation of CO on Au 55 , Ag 13 Au 42 , Au 13 Ag 42 , and Ag 55 metal clusters of nm size. The structures of oxidation intermediates and at the transition states on the potential-energy surfaces were derived with the nudged-elastic-band (NEB) method. According to our results, the coupling of CO and O 2 molecules to form intermediate OCOO has the least energy barrier (0.13 eV) on the Ag 13 Au 42 core−shell nanocluster, whereas the dissociation of the O− O bond of OCOO to form CO 2 and O on the Au 13 Ag 42 core−shell nanocluster is the easiest process with a 0.15 eV barrier height. To understand the electronic property of these nanocluster catalysts and their interactions with the adsorbates, we calculated the electron localization functions, Bader charges, and local densities of states; the results were consistent and explicable.

First-principles investigations of the structural, electronic, and magnetic properties of Pt13−nNin clusters

“…In this work, all the first-principles DFT [26,27] calculations are performed in the Vienna Abinitio Simulation Package (VASP) [26,27], with the projector augmented wave method (PAW) pseudopotentials [28]. The density function is treated within the generalized gradient approximation (GGA) [29], using the PerdewBurke-Ernzerhof (PBE) formula [30].…”

Understanding Oxygen Activation on Nanoporous Gold

“…Whereas the dissociation of O 2 * on Au is difficult, in a peroxo-like intermediate X–O–O*, the O–O bond is weakened before cleavage, lowering the activation energy of the following dissociation to X–O* + O* . This phenomenon was found even on Pt surfaces, on which O 2 * has a low dissociation barrier . According to Hibbits and Iglesia, in this case, “a dearth of vacant sites causes O 2 * to react with CO* to form *OOCO* intermediates that undergo O–O cleavage.” Such a possibility of a bimolecular reaction between CO* and O 2 * can also be proposed on np-Au; however, it remains questionable because of a very weak binding of O 2 to gold.…”

Quantum‐Sized Metal Catalysts for Hot‐Electron‐Driven Chemical Transformation

“…Group theory represents one powerful method for deriving a selection rule of the transitions to identify the electronic‐permitted transition modes . The DFT calculations can also be applied to resolve the electronic structures of adsorbates and surface metal atoms of QSMNPs . Continuous efforts on developing theories and calculation tools will benefit the understanding on the fundamental quantum processes.…”