| Autor: |
Li Y; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Li S; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Nagarajan AV; Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States., Liu Z; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Nevins S; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States., Song Y; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.; School of Biomedical Engineering, Research and Engineering Center of Biomedical Materials, Anhui Medical University, Hefei, Anhui 230032, China., Mpourmpakis G; Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States., Jin R; Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States. |
| Abstrakt: |
Electrocatalytic hydrogen evolution reaction (HER) holds promise in the renewable clean energy scheme. Crystalline Au and Ag are, however, poor in catalyzing HER, and the ligands on colloidal nanoparticles are generally another disadvantage. Herein, we report a thiolate (SR)-protected Au 36 Ag 2 (SR) 18 nanocluster with low coverage of ligands and a core composed of three icosahedral ( I h ) units for catalyzing HER efficiently. This trimeric structure, together with the monomeric I h Au 25 (SR) 18 - and dimeric I h Au 38 (SR) 24 , constitutes a unique series, providing an opportunity for revealing the correlation between the catalytic properties and the catalyst's structure. The Au 36 Ag 2 (SR) 18 surprisingly exhibits high catalytic activity at lower overpotentials for HER due to its low ligand-to-metal ratio, low-coordinated Au atoms and unfilled superatomic orbitals. The current density of Au 36 Ag 2 (SR) 18 at -0.3 V vs RHE is 3.8 and 5.1 times that of Au 25 (SR) 18 - and Au 38 (SR) 24 , respectively. Density functional theory (DFT) calculations reveal lower hydrogen binding energy and higher electron affinity of Au 36 Ag 2 (SR) 18 for an energetically feasible HER pathway. Our findings provide a new strategy for constructing highly active catalysts from inert metals by pursuing atomically precise nanoclusters and controlling their geometrical and electronic structures. |
