Ligand effect on the catalytic activity of porphyrin-protected gold clusters in the electrochemical hydrogen evolution reaction.
Daichi EguchiMasanori SakamotoToshiharu TeranishiPublished in: Chemical science (2017)
The "ligand effect" can be used as a novel strategy for enhancing the catalytic properties of metal clusters. Herein, we report the ligand effect of porphyrin derivatives on gold clusters (AuCs, size <2 nm) and gold nanoparticles (AuNPs, size >2 nm) in the electrochemical hydrogen evolution reaction (HER) at pH 6.7. The current density of porphyrin face-coordinated AuCs at -0.4 V vs. reversible hydrogen electrode (RHE) was 460% higher than that of phenylethanethiol-protected AuCs. X-ray photoemission spectroscopy indicated that the approach of porphyrin to the Au surface induced charge migration from the porphyrin to the Au core, leading to a shift in the 5d state of AuCs that resulted in enhanced HER activities. This ligand effect is pronounced in the cluster region due to the large surface-to-volume ratio. These results pave the way for enhancing catalytic activity of metal clusters using ligand design.
Keyphrases
- photodynamic therapy
- gold nanoparticles
- electron transfer
- metal organic framework
- energy transfer
- high resolution
- reduced graphene oxide
- ionic liquid
- magnetic resonance imaging
- oxidative stress
- sensitive detection
- endothelial cells
- high glucose
- silver nanoparticles
- label free
- quantum dots
- solid phase extraction
- carbon nanotubes
- stress induced