123rd General Meeting of the KCS

Type Oral Presentation
Area Student Oral Presentation
Room No. Room 203
Time THU 09:00-09:15
Code ENVR.O-1
Subject The Effects of Metal-doping and Surface Modification on Hydrogen Production Activity of Metal Nanoclusters
Authors Woojun Choi, Kyuju Kwak, Dongil Lee*
Department of Chemistry, Yonsei University, Korea
Abstract Identification of an efficient hydrogen evolution reaction (HER) electrocatalyst is one of the challenging fields to replace fossil fuel. Although many efforts to develop an active HER catalysts, it is still uneasy to answer what is the main factor that influence on HER activities. Among many researches, two factors are commonly accepted that one is thermoneutral binding step with H+ (∆GH = ~0 eV) on solid metal catalysts and another is proton shuttling effect of secondary coordinated ligand of molecular catalysts. Ligand protected Au nanoclusters that have both metallic and molecular-like properties exhibit distinctive electrochemical and HER features. The HER activities of Au nanoclusters could be improved by doping of foreign metal and surface modification. In this presentation, we report electronic structures and catalytic properties of Au25(SR)18 and bimetallic PtAu24(SR)18 nanoclusters (SR = thiolate). The modified catalytic activities were demonstrated by linear sweep voltammetry and controlled potential electrolysis. HER turnover frequency (TOF) of hexanthiol (C6S) protected Au25(C6S)18 (8.8 s-1 at -0.6 V vs. RHE) increased by doping of Pt (PtAu24(C6S)18, 33.4 s-1) and calculated ∆GH by density functional theory supported the enhanced HER activities of doped nanoclusters. The TOF of Pt-doped nanocluster could further increase by introducing proton shuttling sulfonate ligands reached to 100 s-1 at -0.6 V.
E-mail phungse@naver.com