Carbon Deposition during CO2 Electrolysis in Ni-Based Solid-Oxide-Cell Electrodes

Theis Løye Skafte, Christopher R. Graves, P. Blennow, Johan Hjelm

Research output: Contribution to journalConference articleResearchpeer-review

Abstract

The carbon formation threshold in an operating cell was investigated during electrolysis of an idealized reactant atmosphere of CO and CO2. The electrolysis current was gradually increased in steps until the cell voltage spontaneously increased, thereby indicating cell degradation and possibly the onset of carbon deposition. The outlet gas composition at each current step was estimated based on the inlet gas composition and the reactant conversion using Faraday's law. The increase in voltage was observed at lower outlet pCO/pCO2 ratios than that corresponding to the expected thermodynamic threshold for carbon formation. The degradation observed was related to the fuel electrode, as confirmed by electrochemical impedance spectroscopy. Mitigation of the degradation mechanism was attempted by infiltrating gadolinium doped ceria. The onset of carbon deposition was largely unaffected, but the polarization resistance of the electrode during electrolysis was significantly decreased.
Original languageEnglish
JournalE C S Transactions
Volume68
Issue number1
Pages (from-to)3429-3437
Number of pages9
ISSN1938-5862
DOIs
Publication statusPublished - 2015
EventECS Conference on Electrochemical Energy Conversion & Storage with SOFC–XIV - Glasgow, United Kingdom
Duration: 26 Jul 201531 Jul 2015

Conference

ConferenceECS Conference on Electrochemical Energy Conversion & Storage with SOFC–XIV
CountryUnited Kingdom
CityGlasgow
Period26/07/201531/07/2015

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