Superoxide Formation on Isolated Cationic Gold Clusters

Woodham, Alex P.; Fielicke, André

doi:10.1002/anie.201402783

Cited by 37 publications

(90 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In accordance with the general belief that both CO and O 2 activations are important factors in the process of oxidation of CO, we expect that Au 19 Pt cluster may serve as good catalytic agent for this process. [12,15,20,22,42,62,63] In the present article, we explore this possibility by carrying out a detailed study on the catalytic activity of Au 19 Pt cluster in the CO oxidation reaction. For this purpose we systematically investigate adsorption characteristics of both O 2 and CO 1 O 2 on this bimetallic cluster and calculate the corresponding reaction barriers.…”

Section: Introductionsupporting

confidence: 80%

“…[17,33] On the other hand, Molina and Hammer [33] reported that the presence of an alkali atom (Li/Na) in Au 20 cluster can enhance its reactivity towards the adsorption of CO and O 2 molecules. Moreover, in our recent study on the adsorption of CO molecule on the Au 19 Pt bimetallic cluster [61] we find that the CO adsorption energy on Au 19 Pt cluster is enhanced by more than 1 eV and the C-O bond is also activated by around 0.02 Å . These results convincingly demonstrate that the reactivity of gold clusters can be enhanced by suitably doping them.…”

Section: Introductionmentioning

confidence: 81%

“…Moreover, we also study the relationship between the extent of O 2 activation and the CO oxidation process to search for the optimal activity as expected on the basis of the Sabatier principle. [64] To this end we choose two structurally similar and energetically degenerate homotops of the Au 19 Pt cluster and investigate their catalytic activities for the oxidation of CO. Despite their structural similarity, the two homotops exhibit different degree of O 2 activation thus allowing us to sample two different regions of the volcano plot.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Does enhanced oxygen activation always facilitate CO oxidation on gold clusters?

et al. 2015

View full text Add to dashboard Cite

We investigate the catalytic activity of the subnanometer-sized bimetallic Au19Pt cluster for oxidation of CO via first-principles density functional theory calculations. For this purpose we consider two structurally similar and energetically close homotops of the Au19Pt cluster with the Pt atom occupying an edge (Td-E) or a facet (Td-S) site of a 20-atom tetrahedron. Using these homotops as catalysts we calculate the complete reaction paths and the thermodynamic functions corresponding to the oxidation of CO to CO2. It is found that the oxidation of CO on the Td-S isomer occurs through a smaller reaction barrier (0.38 eV) as compared with that on the Td-E isomer (0.70 eV), although the activation of O2 on the latter is much higher than that on the former. Therefore, a clear conclusion is that a higher O2 activation, which is generally believed to be the key factor for CO oxidation, solely cannot determine the catalytic efficiency of the Au-Pt bimetallic clusters. In addition, we find a stronger CO adsorption on the Td-E isomer (2.06 eV) as compared with that on the Td-S isomer (1.68 eV). Although stronger CO adsorption on the Td-E isomer leads to a higher O2 activation; however, high value of CO adsorption energy deteriorates the catalytic activity of the Td-E isomer towards the CO oxidation reaction.

show abstract

Section: Introductionsupporting

confidence: 80%

Section: Introductionmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Does enhanced oxygen activation always facilitate CO oxidation on gold clusters?

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Nevertheless, a definitive proof on the existence of an HGC conformation with more than 20 atoms remained elusive, particularly, among charged gold clusters. Among the neutral clusters, two HGC conformations, viz., Au 18 and Au 32 are widely studied for their potential electronic and catalytic properties [35][36][37][38][39][40]. These studies validate that both the HGCs are excellent red-ox agents and can be even an eminent choice for the selective oxidation of styrene to benzaldehyde [37].…”

Section: Introductionmentioning

confidence: 71%

Behaviour of ‘free-standing’ hollow Au nanocages at finite temperatures: a BOMD study

Joshi

Krishnamurty

2015

Molecular Physics

View full text Add to dashboard Cite

Finite-temperature behaviour of a hollow golden cage (HGC) plays a crucialrole in its potential applications as a catalyst, drug delivery agent, contrasting agent and so on. This physico-chemical property of HGCs is not well understood so far. In that context, Born-Oppenheimer molecular dynamics (BOMD) simulations are performed on a well-known 'free-standing' HGC. The cluster considered in this study is the ground state Au 18 cluster (a cage with a diameter of about >5.5Å).The results thus obtained are compared with the BOMD simulation results reported earlier on Au 32 icosahedron cage, a conformation with a diameter of nearly. The sphericity of both the clusters is studied using a shape deformation parameter as a function of time and temperature. These results are supplemented by radial distribution function at various temperatures. The observations and analysis of results indicate that, both the clusters retain an HGC conformation from 300 to 400 K, admitting structural fluxionality by the Au 18 cluster. Remarkably, the Au 18 cluster is able to maintain its hollowness and sphericity up to a high temperature of 1000 K. Underlying structural and electronic properties influencing the individualistic behaviour of cages are highlighted. Composition of the frontier molecular orbitals and the charge distribution play a crucial role in the finite-temperature behaviour of the Au cages. The conclusions are supplemented by supporting calculations on another degenerate ground state Au 18 hollow cage and a well-known pyramidal Au 18 cage at 300 and 400 K.

show abstract

“…The amount of electron transfer to oxygen indicated that oxygen is molecularly chemisorbed with pronounced size‐dependent variations in its reactivity 9b. 15d, 17c, 38c, 40…”

Section: Introductionmentioning

confidence: 99%

Physisorption and Chemisorption on Silver Clusters

et al. 2015

View full text Add to dashboard Cite

Adsorption and coadsorption studies on free silver clusters show that nitrogen physisorbs like rare gases, whereas oxygen chemisorbs with similarities and differences to bulk silver surfaces. Silver nanoparticles activate, or even dissociate adsorbed oxygen molecules. The global electron configurations of the adsorbent and adsorbate dominate the stability at small clusters. This is more important than geometry and site effects. Due to electronic shell effects and electron pairing, the activation of oxygen strongly varies with size. At more than 40 free electrons in the complex, such quantum effects start to blur. The size dependence becomes smoother and general trends govern the reactivity, which is driven by the interaction between the charge state of the nanoparticle and the charge transfer of the reaction.

show abstract

Superoxide Formation on Isolated Cationic Gold Clusters

Cited by 37 publications

References 31 publications

Does enhanced oxygen activation always facilitate CO oxidation on gold clusters?

Does enhanced oxygen activation always facilitate CO oxidation on gold clusters?

Behaviour of ‘free-standing’ hollow Au nanocages at finite temperatures: a BOMD study

Physisorption and Chemisorption on Silver Clusters

Contact Info

Product

Resources

About