The Interactions of Oxygen with Small Gold Clusters on Nitrogen-Doped Graphene

Molecules

Xin Chen¹  Shaorui Sun¹  Fan Li¹  Xiayan Wang¹ 

[1]College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China

关键词: gold cluster;    graphene;    oxygen adsorption;    density functional theory;   

DOI  :  10.3390/molecules18033279

来源: mdpi

【 摘 要 】

By means of density functional theory, the adsorption properties of O₂ molecule on both isolated and N-graphene supported gold clusters have been studied. The N-graphene is modeled by a C₆₅NH₂₂ cluster of finite size. The results indicate that the catalytic activity and the O₂ adsorption energies of odd-numbered Au clusters are larger than those of adjacent even-numbered ones. The O₂ molecule is in favor of bonding to the bridge sites of odd-numbered Au clusters, whereas for odd-numbered ones, the end-on adsorption mode is favored. The perpendicular adsorption orientation on N-graphene is preferred than the parallel one for Au₂, Au₃ and Au₄ clusters, while for Au₅, Au₆ and Au₇, the parallel ones are favored. When O₂ is adsorbed on N-graphene supported Au clusters, the adsorption energies are largely increased compared with those on gas-phase ones. The increased adsorption energies would significantly facilitate the electron transfer from Au d-orbital to π* orbital of O₂, which would further weakening the O–O bond and therefore enhancing the catalytic activity. The carbon atoms on N-graphene could anchor the clusters, which could make them more difficult to structural distortion, therefore enhance their stability.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.