Theoretical Investigationons On The Structures And Stabilities Of Gold Clusters And Adsorption To HCHO

Excessive formaldehyde(HCHO) hazarding human health has caused extensive concerns. Gold nanoparticles can better catalyze the oxidation and elimination of HCHO, but controversies exist in the shap and charge of active gold. As for it, theriotical investigations were performed on the structures,stabilities and adsorptions to HCHO for different shap-charge gold clusters.First, the stabilities of clusters Aunz(n=2~12; z= 0/+1/-1) were analysed.The results show that 2D-3D transition happens in different size and the clusters with more than 8 Au atoms tend to be cake-configuration.Electron-paired effect radically causes odd-even oscillation in thermal stabilities of clusters as the size increasing.Second, shape-effect adsorptions to HCHO for planar, cake and serrate Aun(n= 8~10) were studied. Results showed that the Au―O interaction is over the Au―H interaction. Low-coordinated Au atoms exhibit stronger adsorption. Aromatic circulations conduce to planar configurations. To activate HCHO, inner Au atoms in the planar are almost ineffective and secondary-adsorption Au atoms of Cake-Au10 perform better.Last, charge-effect adsorptions to HCHO for Cake-Aunz(n= 8 ~ 10;z=0/+1/?1) were investigated. It is found that Au―O interaction is primary for Cake-Aun0/+1, but Au―H interaction for Cake-Aunˉ. Stronger adsorptions mainly activate the C=O and weaker adsorptions tend to activate the C―H.Cake-Au10+ better activates the C=O and C―H bonds simultaneously.