Ionically Conducting Ceramics for Soot Oxidation Mechanistic Study with 18O2 Isotopic Exchange

L. LIZARRAGA; E. OBEID; M.N. TSAMPAS; A. BOREAVE; M.C. STEIL; P. VERNOUX

Seattle

Encuentro; 221th Electrochemical Society Meeting; 2012

Electrochemical Society

This study shows that Yttria-Stabilized Zirconia (YSZ) is an effective catalyst for soot particles oxidation. Soot oxidation already occurs from 270°C. Temperature-Programmed Oxidation experiments with 18O2 demonstrate the key-role of bulk oxygen species in the oxidation process. To the best of our knowledge, this is the first time that such a result is reported for a purely O2- ionically conducting ceramic without any redox property. We assume that the soot oxidation takes place via a fuel-cell type electrochemical mechanism at the nanometric scale. Electrochemical oxidation of the soot takes place at the soot/YSZ interface while oxygen electrochemical reaction occurs at the triple phase boundary.