Werchmeister, Rebecka Maria Larsen3; Kammer Hansen, Kent1
1 Department of Energy Conversion and Storage, Technical University of Denmark2 Fundamental Electrochemistry, Department of Energy Conversion and Storage, Technical University of Denmark3 Department of Chemistry, Technical University of Denmark
The ability of praseodymium doped cerium oxide materials to electrochemically reduce NO and O2 was studied using cone-shaped electrodes in conjunction with cyclic voltammetry, in the temperature range 200–400 °C. Four samples were studied; Ce1−xPrxO2−δ (x = 0.1, 0.2, 0.3 and 0.4). It was shown that the current densities in both NO an O2 gases increased with increasing praseodymium doping. Ce1−xPrxO2−δ had higher activity in an atmosphere containing NO than in an atmosphere containing O2 in most cases and this trend was stronger at the lower temperatures. Ce0.8Pr0.2O2−δ and Ce0.9Pr0.1O2−δ seemed to have the highest ratio of maximum cathodic current density (iNO/iO2iNO/iO2), which is used as an indication of a higher activity toward reduction of NO compared to reduction of O2. The apparent selectivity generally decreased with increasing temperature for all the compositions.