关键词: 金纳米粒子, 氢解离机理, 水助催化, Raman光谱

Abstract: The gold nanoparticles (GNPs) show special activity toward hydrogen (H₂) dissociation, comparing with bulk gold. Such activity is significantly affected by the existence of water. To inspect the influence of water on GNPs catalyzed H₂ dissociation, we carried out density functional theory (DFT) calculations along the reaction paths for water clusters (H₂O)_m (m = 1, 2, 3, 7) assisted H₂ dissociation on gold clusters (Au_n^δ, n = 3 ~ 5; δ = 0, 1). Our calculated results show that water benefits to the H₂ dissociation. The dissociation mechanism varies with the size of water clusters, from the homolytic cleavage of the H-H bond to the oxidation dissociation mechanism on the small gold clusters. We also suggest Raman and IR spectroscopies can be used to characterize the products of those two mechanisms.

Key words: gold nanoparticles, hydrogen dissociation, water assisted reaction, density functional theory, Raman spectroscopy.