Dissociation reactions of hydrogen molecules at active sites on gold clusters: A DFT study

Small gold nanoparticles (GNPs) show special catalytic activity for hydrogen (H-2) dissociation reaction, which is essential and important in understanding the hydrogen oxidation reaction in hydrogen energy source. To insight on catalytic properties of GNPs, we simulated H-2 dissociation paths on neutral gold clusters (GCs) Au-n (n = 1-6) and positively charged GCs Au-n(+) (n = 3-5), which are possible active sites on GNPs. The calculated results show that H-2 dissociation on GCs follows a homolytic cleavage reaction process. Light irradiation and water environment are considered for H-2 dissociation on Aun delta+ (n = 3-5, delta = 0 and +1) clusters. The calculated results show that when the incident light has a low energy close to the surface plasmon resonance (SPR) region of GNPs, the light can effectively reduce the H-2 dissociation barrier, and an oxidation dissociation process is found for the water-assisted H-2 dissociation reaction.

Automated summary

Small gold nanoparticles (GNPs) exhibit special catalytic activity for hydrogen (H-2) dissociation reaction. Simulation experiments revealed that H-2 dissociation on gold clusters occurs through a homolytic cleavage reaction process, and both light irradiation and water environment can assist and promote the dissociation process.