Morphological Effects of Gold Clusters on the Reactivity of Ceria Surface Oxygen

Abstract

Well-defined {100}-faceted ceria nanocube-supported gold nanoclusters with various morphologies, including individual atom, monolayer, multilayer and nanoparticle, have been synthesized and systematically investigated combined with density functional theory calculations. A strong morphological effect of gold clusters on the reactivity of ceria surface oxygen has been identified. The reducibility and CO oxidation activities of Au/CeO 2 catalysts increased significantly as the morphology of the gold clusters changed from single atoms to monolayer, then to multilayer, then nanoparticles. It was revealed that up to a bilayer of gold clusters were needed for desirable catalytic performance in the Au/ CeO 2 system. The transfer of electrons from gold clusters to the surface Ce−O groups of ceria and strong Au−Au interactions play significant roles in determining the reducibility of surface oxygen of CeO 2 .

Sol‐immobilized vs deposited‐precipitated Au nanoparticles supported on CeO2 for furfural oxidative esterification

“…In addition, the created oxygen vacancies could further play a role by activating the oxygen molecules coming from the gas phase and therefore enhance the reactivity of the Au/CeO 2 system. A strong morphological effect of gold on the reducibility and on the CO oxidation activity of ceria was established . In the present study, as for the samples prepared by sol‐immobilization, all defective ceria supports play a greater role in the reaction than a ceria support that is strongly interacting with gold nanoparticles.…”

Shape Engineering of Oxide Nanoparticles for Heterogeneous Catalysis

“…[50] The interaction betweenA ua nd {100}-facetedC eO 2 nanocubes has been studied furtherb yv arying the morphologyo fg old, including single atom, monolayer, multilayer,a nd nanoparticle ( Figure 4e). [51] The multilayer and nanoparticle systems are ablet oa chieve complete CO oxidation at 373 and 473 K, respectively,w hereas the single-atom and monolayer samples are almosti nactive to CO oxidation below 573 K ( Figure 4f,g). Moreover,t he temperature towards hydrogen reduction increases in the order nanoparticle < multilayer < monolayer < single atom.…”

“…DFTcalculations suggest that electron transfer from the gold clusters to the surface CeÀO groups and strongA u-Au interactions play significant roles in determining the reducibility of surfaceo xygen of CeO 2 and thereby the catalytic performance. [51]…”

The influence of support materials on the structural and electronic properties of gold nanoparticles – a DFT study

“…37 Nevertheless, the quest for understanding the structure activity relationship of supported gold catalysts is still ongoing. The adsorption of gold atoms and clusters on magnesia, [38][39][40][41][42] ceria, [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] and graphene/graphite [62][63][64][65][66][67][68][69][70][71][72][73][74][75] has been at the centre of previous computational studies. However, their scope was mostly limited to single adatoms or specific cluster sizes and only one support material.…”