Yoo, Hyun D. Jang, Jong Hyun Ka, Bok H. Rhee, Choong Kyun Oh, Seung M. 2024-01-20T20:32:15Z 2024-01-20T20:32:15Z 2021-09-05 2009-10-06 0743-7463 https://pubs.kist.re.kr/handle/201004/132039 Electrochemically active surface area (ECA) of a polycrystalline Pt electrode is measured from the pseudocapacitance (C-p) values that are associated with hydrogen under potential deposition. The potential-dependent C-p Values are extracted from the raw impedance data by removing the interferences coming from the double-layer charging and hydrogen evolution. Three different approaches have been made: (i) by using the proportionality between the capacitance and area of the capacitive peak on imaginary capacitance plots, (ii) by complex nonlinear least-squares (CNLS) fitting on both the imaginary and real part of complex capacitance with appropriate equivalent circuits, and (iii) by using the modified Kramers-Kronig (K-K) relation. The first approach is the simplest one for the C-p measurement but cannot be used in the hydrogen evolution region (< 0.05 V vs RHE), whereas the measurement can be extended down to -0.01 V with the second method. The isotherm fitting on the C-p(E) profile shows that the saturation of adsorbed hydrogen is reached at -0.1 V vs RHE. Faster data acquisition is possible with the third approach since the data analysis call be made without the time-consuming low frequency data (< 100 Hz). The roughness factor and ECA of the Pt electrode are calculated from the electric charge that is obtained by integrating the potential-dependent C-p values; the roughness factor (1.4-1.5) lies within the normal range for planar electrodes. English AMER CHEMICAL SOC COMPLEX CAPACITANCE ANALYSIS DOUBLE-LAYER CAPACITANCE SINGLE-CRYSTAL FARADAIC REACTIONS CORROSION RATES AC IMPEDANCE PLATINUM EVOLUTION KINETICS PT(111) Impedance Analysis for Hydrogen Adsorption Pseudocapacitance and Electrochemically Active Surface Area of Pt Electrode Article 10.1021/la900290b 1 LANGMUIR, v.25, no.19, pp.11947 - 11954 LANGMUIR 25 19 11947 11954 scie scopus 000270136900108 2-s2.0-70349898790 Chemistry, Multidisciplinary Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article COMPLEX CAPACITANCE ANALYSIS DOUBLE-LAYER CAPACITANCE SINGLE-CRYSTAL FARADAIC REACTIONS CORROSION RATES AC IMPEDANCE PLATINUM EVOLUTION KINETICS PT(111) Impedance Platinum Hydrogen Adsorptioin