Modelling Study of Surface Reactions, Diffusion, and Spillover at a Ni/YSZ Patterned Anode
- 1 January 2009
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 156 (5), B663-B672
- https://doi.org/10.1149/1.3095477
Abstract
This paper presents a modelling study of the electrochemical hydrogen oxidation reaction at nickel/yttria-stabilized zirconia (Ni/YSZ) patterned anodes. An elementary kinetic reaction-diffusion model accounts for coupled heterogeneous chemistry and transport on the Ni and YSZ surfaces. Charge transfer is modeled as a spillover of adsorbates between the Ni and YSZ surfaces at the three-phase boundary (TPB). No a priori assumptions on rate-determining processes are made. Thermodynamic, kinetic, and transport parameters are compiled from various literature sources serving as a base for quantitative simulations. Seven different spillover reaction pathways of the hydrogen oxidation reaction are compared to experimental patterned anode data obtained previously by Bieberle et al. [ J. Electrochem. Soc. , 148 , A646 (2001)] under a range of operating conditions. Only one reaction pathway, based on two hydrogen spillover reactions, is able to describe consistently the complete experimental data set. A sensitivity analysis for this case allows identification of rate-determining processes. Surface concentrations close to the TPB are predicted to differ from the concentration derived from thermodynamical equilibrium by up to 2 orders of magnitude. The simulation results and the validity of the model are critically discussed. Directions for future theoretical and experimental studies for elucidating the mechanistic details of Ni/YSZ anodes are given.Keywords
This publication has 38 references indexed in Scilit:
- A new framework for physically based modeling of solid oxide fuel cellsElectrochimica Acta, 2007
- The influence of equilibrium potential on the hydrogen oxidation kinetics of SOFC anodesSolid State Ionics, 2007
- Modeling of environmentally significant interfaces: Two case studiesJournal of Electron Spectroscopy and Related Phenomena, 2006
- Electrochemical Oxidation of H[sub 2], CO, and CO?H[sub 2] Mixtures on Patterned Ni Anodes on YSZ ElectrolytesJournal of the Electrochemical Society, 2006
- A new computational approach for SOFC impedance from detailed electrochemical reaction–diffusion modelsSolid State Ionics, 2005
- Advanced anodes for high-temperature fuel cellsNature Materials, 2004
- H[sub 2]-H[sub 2]O-Ni-YSZ Electrode PerformanceJournal of the Electrochemical Society, 2004
- Surface diffusion and concentration polarization on oxide-supported metal electrocatalyst particlesSurface Science, 2003
- The Electrochemistry of Ni Pattern Anodes Used as Solid Oxide Fuel Cell Model ElectrodesJournal of the Electrochemical Society, 2001
- A Study of Metal (Ni, Pt, Au)/Yttria-Stabilized Zirconia Interface in Hydrogen Atmosphere at Elevated TemperatureJournal of the Electrochemical Society, 2001