121st General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for Young Scientist in Environmental and Energy Chemistry
Room No. Room 201B
Time THU 09:00-:
Code ENVR.O-1
Subject Electrocatalytic Hydrogen Production on Molecular-like Metal Nanoclusters
Authors woojun choi, Kyuju Kwak, Dongil Lee*
Department of Chemistry, Yonsei University, Korea
Abstract Considering hydrogen as a clean and renewable energy source, electrocatalytic hydrogen evolution reaction (HER) is one of the great challenging fields to replace the fossil fuel. Thus, the identification of an efficient electrocatalysts include thermoneutral binding step with H+ (∆GH = ~0 eV) is the main key for sustainable energy supplement. Ligand protected Au nanoclusters and bimetallic nanoclusters exhibit distinctive electrochemical properties and unique HER activities. In this presentation, we report electronic structures and catalytic properties of Au25(SR)18 and Au38(SR)24 nanoclusters (SR = thiolate). Foreign metal doping on Au nanoclusters resulted bimetallic MAu24(SR)18 and M2Au36(SR)24 (M = Pt and Pd) and their modified catalytic activities were demonstrated by linear sweep voltammetry and controlled potential electrolysis. HER turnover frequency (TOF) of Au25 (8.8 s-1 at -0.6 V vs RHE) increased by doping of Pd (13.0 s-1) and further enhanced by doping of Pt (33.4 s-1). Calculated ∆GH by density functional theory supported the enhanced HER activities of Pd and Pt doped nanoclusters. Altered ∆GH by doping also influenced on TOFs of M2Au36 as a same manner of MAu24 nanoclusters. Furthermore, PtAu24 catalyze hydrogen production from very low onset potential (-0.07 V vs. RHE) due to matched reduction potential with H+ whereas Au25 have mismatched reduction potential and higher onset potential (-0.20 V). The outstanding HER activity of PtAu24 was clearly manifested when comparing with the commercial Pt/C catalyst.
E-mail phungse@naver.com