123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Scholars in Electrochemistry
Room No. Room 407+408
Time THU 09:50-10:00
Code ELEC.O-6
Subject Unraveling the Controversy over the Catalytic Reaction Mechanism using a New Theoretical Methodology: One Probe and Non-Equilibrium Surface Green’s Function
Authors Chiho Lee, Sang Uck Lee*
Department of Bio-Nano Engineering, Hanyang University, Korea
Abstract We shed light on the longstanding controversial issues on the iodine reduction reaction (IRR) mechanism using a new proposed methodology called “One Probe and Non-equilibrium Surface Green’s function (OPNS)”. The OPNS approach completely alleviates the limitations of traditional slab approach for the electrocatalytic reactions by coupling the surface to an infinite reservoir of electrons at a fixed chemical potential and implements an external electric field environment through a semi-infinite one probe model. With aid of OPNS and in-depth structural analysis under the external electric field, we re-evaluated the previously proposed IRR mechanisms on the Pt(111) surface, consecutive and concerted mechanisms. Our results reveal that the configurational preference of approaching I2 molecules depending on the external electric field governs the IRR mechanism. Under the reductive potential, I2 molecules prefer vertical (I2V) configuration rather than parallel (I2P) configuration, which leads to the consecutive mechanism where I atoms are sequentially reduced due to asymmetric charge accumulation on a single I atom to be initially desorbed. Consequently, we can clarify that the IRR follows the consecutive mechanism and we believe that the new OPNS method and the proposed onset threshold electric field for reduction as an effective descriptor of catalytic activity evaluation can inspire the study of electrocatalytic reactions for various catalysts.
E-mail holee@cms.hanyang.ac.kr