|
|
| Type |
Oral Presentation |
| Area |
Current Trends in Environmental and Energy Chemistry |
| Room No. |
Room 301 |
| Time |
THU 09:00-: |
| Code |
ENVR.O-1 |
| Subject |
Electrocatalytic Hydrogen Production Using Ligand-Protected Metal Nanoclusters |
| Authors |
Kyuju Kwak, woojun choi, Dongil Lee*
Department of Chemistry, Yonsei University, Korea
|
| Abstract |
Hydrogen has been considered as an alternative energy carrier and generated the intense interest in creating catalytic systems that can efficiently produce hydrogen from water. Hydrogen evolution reaction (HER) has been studied with various catalysts such as bulk metals and metal complexes represented by Pt metal and hydrogenase. Ultra-small metal nanoclusters, especially molecular-like Au25 nanoclusters that have similar characteristic with both bulk metals and metal complexes have distinctive catalytic activities. Furthermore, the activity for the catalytic reactions can be readily controlled by introducing a foreign metal such as Pt into the nanocluster platform or tuning the ligands with functional groups. In this presentation, we report that atomically engineered metal nanoclusters for example, Au25(SR)18 and PtAu24(SR)18 where SR is thiolate, can be effectively used as HER catalysts. First, mono Pt doped Au25(SR)18, PtAu24(SR)18, shows remarkable HER activity with very low onset-potential (Eonset= 70 mV vs. RHE) that is comparable to that of natural hydrogenase (~100 mV) enzymes. This can be ascribed to the positive shift of the reduction potential that matches well with the reduction potential of proton and its thermodynamically neutral binding energy for proton adsorption. Second, sulfonate ligands-protected PtAu24(SR)18 exhibits rate constant of 628,000 s-1 in water at moderate overpotential (0.7 V); significantly higher than that reported to date for the highest active nickel complex (170,000 s-1 at 0.47 V) catalysing hydrogen formation with pendant amines. The functional group of the thiolate ligands is particularly effective in increasing the accessibility of proton, most likely facilitated by proton relay effect between solvent to active-site. These results highlight the importance of metal core and ligand engineering as an indispensable tool in the rational design of metal nanoclusters, which can improve the catalytic properties of nanocluster catalysts. |
| E-mail |
kkj818@yonsei.ac.kr |
|
120th General Meeting of the KCS