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CO 2 Reduction on the Pre‐reduced Mixed Ionic–Electronic Conducting Perovskites La 0.6 Sr ‐0.4 FeO 3‐δ and SrTi 0.7 Fe 0.3 O 3‐δ
Author(s) -
Grünbacher Matthias,
Götsch Thomas,
Opitz Alexander K.,
Klötzer Bernhard,
Penner Simon
Publication year - 2018
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201700970
Subject(s) - hydrogen , oxide , chemistry , inorganic chemistry , temperature programmed reduction , ionic bonding , reactivity (psychology) , desorption , proton , analytical chemistry (journal) , ion , adsorption , medicine , alternative medicine , organic chemistry , pathology , physics , quantum mechanics , chromatography
The activity of the pre‐reduced perovskites La 0.6 Sr 0.4 FeO 3‐δ (LSF64) and SrTi 0.7 Fe 0.3 O 3‐δ (STF73) for the CO 2 reduction to CO was investigated with special focus on the reactivity of oxide‐dissolved hydrogen. This is of particular interest in hydrogen solid‐oxide electrolysis cell (H‐SOEC) technology, where proton‐conducting ceramics are used and the reaction 2e − +2H + +CO 2 →CO+H 2 O is of central importance. To clarify if hydrogen dissolved in LSF64 and STF73 partakes in the CO 2 reduction, temperature‐programmed reduction (TPR) in H 2 , followed by temperature‐programmed reoxidation (TPO) in CO 2 and, moreover, temperature‐programmed desorption (TPD) of ad‐ and absorbed species were utilized. The experiments reveal that 50 mol % of the CO 2 is converted by hydrogen dissolved in STF73 and reacts quantitatively. On the other hand, LSF64 converts less than 20 mol % of CO 2 via dissolved hydrogen and a residual of bulk OH is still detectable after CO 2 ‐TPO.