Metallic Hydrogen in Atomically Precise Gold Nanoclusters

Abstract

Hydrogen−metal interaction is the foundation of many technologies and processes, but how hydrogen behaves in atomically precise gold nanoclusters remains unknown even though they have been used in hydrogenation catalysis and water splitting. Herein, we investigate how hydrogen interacts with [Au 25 (SR) 18 ] q clusters and mono-atom-doped bimetallic [M 1 Au 24 (SR) 18 ] q clusters (M = Pt, Pd, Ag, Cu, Hg, or Cd) from first principles. We find that hydrogen behaves as a metal in these clusters and contributes its 1s electron to the superatomic free-electron count. This opposite behavior compared to that of the hydride in Cu and Ag clusters allows the small hydrogen to interstitially dope the gold clusters and tune their superatomic electronic structure. The doping energetics shows that when an eight-electron superatom is formed after H doping, the binding energy of H is much stronger, while binding of H with an already eight-electron superatom is much weaker. Indeed, frontier orbitals and the HOMO−LUMO gaps of [Au 25 H 1 (SR) 18 ] 0 , [Au 25 H 2 (SR) 18 ] + , [PtAu 24 H 2 (SR) 18 ] 0 , [PdAu 24 H 2 (SR) 18 ] 0 , [AgAu 24 H(SR) 18 ] 0 , and [CuAu 24 H(SR) 18 ] 0 all have very similar features, because they are all eight-electron superatoms. By calculating the Gibbs free energies of hydrogen adsorption, we predict that PtAu 24 (SR) 18 , PdAu 24 (SR) 18 , and center-doped CuAu 24 (SR) 18 can be good electrocatalysts for the hydrogen evolution reaction.

Photo/electrocatalysis and photosensitization using metal nanoclusters for green energy and medical applications

“…On the other hand, Lee and Jiang et al investigated the effect of heteroatom doping of Au n (SR) m NCs on the HER activity. [28][29][30][31] They examined the HER activity of hexanethiolate (C6)protected Au 25 and PtAu 24 NCs in a tetrahydrofuran (THF) electrolyte containing 1.0 M triuoroacetic acid (TFA) ( Fig. 4A-C).…”

Gold Nanoclusters as Electrocatalysts for Energy Conversion

“…These results are in good agreement with the DFT calculation results. In addition to these studies, Jiang et al, also investigated the doping effects of various elements (Pt, Pd, Ag, Cu, Hg, and Cd) in Au 25 (SCH 3 ) 18 using DFT calculations [105]. The results predicted that Au 24 Pt(SCH 3 ) 18 , Au 24 Pd(SCH 3 ) 18 , and Au 24 Cu(SCH 3 ) 18 , in which the heteroatom (Pt, Pd, or Cu) is located at the center of the metal core, have a higher HER activity than Au 25 (SCH 3 ) 18 .…”

“…Fine nanoparticle catalysts suitable for the HER [88][89][90][91][92], OER [93][94][95], and ORR [96][97][98][99][100][101] have been developed based on theoretical predictions of activity volcano plots using various metals and alloy nanoparticles (NPs). Au n NCs have recently been observed to possess catalytic activity for the HER, OER, and ORR [77, [102][103][104][105][106][107][108][109][110][111][112][113][114][115][116] (Figure 1). Therefore, Au n NCs are expected to become a model catalyst even in such an energy conversion system.…”

Gold‐Hydrogen Nanoclusters: Atom‐Precise Model to Unveil Catalytic Mechanism and Growth Process of Gold Nanoparticles

“…Theoretical studies were employed to understand the hydrogen‐metal interaction in gold clusters. Jiang group investigated how hydrogen interacts with [Au 25 (SR) 18 ] q clusters from first principles, and found that hydrogen behaves like a metal in these clusters and contributes its 1s electron to superatomic free‐electron count . The same group also studied the hydrogen‐gold interaction in the phosphine‐protected Au 22 (L) 6 cluster [L = 1,8‐bis(diphenylphosphino)octane] with eight coordinatively unsaturated Au atoms .…”