Chemical sensors with catalytic metal gates - Switching behavior and kinetic phase transitions
1998 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, Vol. 145, no 10, 3401-3406 p.Article in journal (Refereed) Published
Rapid transitions in the response of platinum-based chemical sensors occurring at given hydrogen-oxygen concentration ratios are explained by kinetic phase transitions or switching phenomena on the catalytic metal surface. Below the transition point the response of platinum-insulator silicon carbide devices is small and above the transition it is large. It is found that the critical ratio depends on the operation temperature and the properties of the device. Three different cases are identified, namely, injection-, diffusion-, and reaction-rate-determined transitions. At sufficiently large temperatures the transition is injection limited and occurs at the stoichiometric ratio of hydrogen and oxygen in the gas mixture. The implications of the experimental observations on the applications of chemical sensors with catalytic sensing layers are discussed.
Place, publisher, year, edition, pages
Electrochemical Society, 1998. Vol. 145, no 10, 3401-3406 p.
chemical sensors, gas sensors, electric sensing devices, catalysis, surface chemistry, MIS devices, electric properties
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-88122DOI: 10.1149/1.1838819ISI: 000076217000015OAI: oai:DiVA.org:liu-88122DiVA: diva2:601805