On the platinum sensitization of nanosized cerium dioxide oxygen sensors

Cerium dioxide (CeO2) or ceria based oxygen sensors are currently being explored as possible candidates for oxygen sensing with application especially in sensing automotive exhaust gases. Ceria synthesized by the hydrazine hydrate method has been shown to be a highly efficient material for oxygen sensing in the temperature range of 888-1275 K. The present study demonstrates that the sensitivity as well as the response time t(90) could be improved by using nanosized CeO2 (50-100 nm) compared to the coarse-grained material. Further the gas sensing characteristics of pure nanosized ceria are compared with those of Pi incorporated ceria. These latter studies have shown that the noble metal improves the response of the oxygen sensor significantly and definitely has a role in the sensitization mechanism for oxygen sensing. (C) 2003 Elsevier Science B.V. All rights reserved.