Effect of Silicon Doping on the Reactivity and Catalytic Activity of Gold Clusters

Abstract

Doping is known to be an excellent and simple way of catalyst design. Although notable progress has been made in understanding the reactivity and catalytic activity of gas-phase and supported gold clusters, very few studies have been carried out on the doped gold clusters. In the present work, we have carried out density functional theory calculations to investigate the effect of silicon doping on the reactivity and catalytic activity of gold nanoclusters. The present work particularly focuses on the adsorption and activation of molecular oxygen on the pristine and silicon-doped gold clusters. The results confirm that the silicon-doped Au7Si cluster shows considerable binding and activation of the O2 molecule in comparison to the pristine Au8 cluster as reflected in the relevant geometrical parameters (O–O and Au–O bond lengths) and O–O stretching frequency. However, silicon doping has no contrasting effect on the reactivity and catalytic activity of the Au7 cluster. In addition to the stronger binding and activation of the O2 molecule, the doped Au7Si cluster leads to a significant reduction in the activation barrier (0.57 eV) for the environmentally important CO oxidation reaction in contrast to the catalytically inactive pristine Au8 cluster (1.22 eV). Thus, our results highlight the critical role of doping foreign impurities for future endeavors in the field of gold nanocatalysis.

Nonadiabatic scattering of NO off Au3 clusters: A simple and robust diabatic state manifold generation method for multiconfigurational wavefunctions

“…We used the Modified LANL2DZ basis set by Hay and Wadt that replaces the 60 core electrons of Au atoms by an effective core potential (ECP) obtained from calculations which incorporate relativistic corrections, and contracted Gaussian basis functions for the remaining 19 valence electrons (5s 2 5p 6 5d 10 6s 1 ). This basis set has been widely used in a number of articles for studying properties of gold clusters . Three gold atoms have 57 valence electrons, and a preliminary CAS(7,4) calculation, using Cs symmetry, including the HOMO/LUMO of each symmetry resulted in a 2 E neutral cluster and 1 A 1 cation cluster (labels in C 3 v ).…”

Catalytic Activities of Au6, , and Clusters for CO oxidation: A density functional study

“…They observed that the neutral Au 6 cluster is stable up to 1100 K, whereas the cationic and the anionic clusters are stable up to 500 K. On ligating the cluster with CO, the neutral and anionic conformations are stable up to 800 K whereas the cationic cluster collapses at room temperature. In a recent work by Manzoor et al on silicon‐doped gold clusters, they have observed preferential binding and activation of the O 2 molecule in Au 7 Si in comparison to Au 8 cluster. Further the Au 7 Si cluster exhibited enhanced catalytic activity for CO oxidation.…”

Reactions involving some gas molecules through sequestration on Al12Be cluster: An electron density based study

“…We note that the significance of the concerned reactions is well‐known in the scientific literature and each of these reactions presents some unique challenges. CO oxidation reaction has important implications on the environment and to this end, Au based metal clusters are considered to be among the best performing catalytic agents . CF bond decomposition from alkyl/aryl halides could be a very useful pathway toward CC bond formation processes and as a result CF bond activation represents an interesting research topic .…”