Title :
Strategies for improving sensitivity to nitrogen oxides in electrochemical gas sensors for lean combustion engines
Author :
López-Gándara, Carlos ; Fernández-Sanjuán, Josep M. ; Ramos, Francisco M. ; Cirera, Albert
Author_Institution :
Electron. Dept., Univ. de Barcelona, Barcelona, Spain
Abstract :
Sensitivity to nitrogen monoxide (NO) was studied in conventional planar exhaust gas sensors after implementing layers made of microstructured or nanostructured tungsten trioxide (WO3) over one of their electrodes. The sensors were made of an YSZ solid electrolyte and covered by two catalytic Pt-based electrodes. They showed different sensitivities to NO depending on the WO3 layer configuration: nanostructured WO3, microstructured WO3, YSZ mixed with WO3, etcetera. Sensitivity in terms of each layer configuration has been attributed to a competition between diffusion and catalytic activity in each layer. Maximum sensitivity to NO in multi-component gas mixtures was found in sensors with 20μm-thin layers of nanostructured WO3.
Keywords :
electrochemical electrodes; electrochemical sensors; engines; gas sensors; nitrogen compounds; solid electrolytes; tungsten compounds; yttrium compounds; zirconium compounds; NO; Pt-based electrode; Y2O3-ZrO2-WO3; YSZ solid electrolyte; electrochemical gas sensor; lean combustion engine; multicomponent gas mixture; sensitivity; size 20 mum; Electrodes; Gas detectors; Nitrogen; Sensitivity; Sensor phenomena and characterization; Temperature sensors; diffusion; exhaust gas sensor; lambda sensor; nanostructured layer; tungsten trioxide;
Conference_Titel :
Electron Devices (CDE), 2011 Spanish Conference on
Conference_Location :
Palma de Mallorca
Print_ISBN :
978-1-4244-7863-7
DOI :
10.1109/SCED.2011.5744172
