Study of the Sensing Mechanism Towards Carbon Monoxide of Platinum-Based Field Effect Sensors
Journal article, 2011
We have investigated the temperature dependence and the effect of hydrogen on the CO response of MISiC field effect device sensors. The evolution of adsorbates on a model sensor was studied by in situ DRIFT spectroscopy and correlated to sensor response measurements at similar conditions. A strong correlation between the CO coverage of the sensor surface and the sensor response was found. The temperature dependence and hydrogen sensitivity are partly in agreement with these observations, however at low temperatures it is difficult to explain the observed increase in sensor response with increasing temperature. This may be explained by the reduction of a surface oxide or removal of oxygen from the Pt/SiO2 interface at increasing temperatures. The sensing mechanism of MISiC field effect sensors is likely complex, involving several of the factors discussed in this paper.
co oxidation
gas sensors
oxygen
platinum
palladium
hydrogen
temperature
diffuse reflectance infrared Fourier transform (DRIFT)
spectroscopy
pt(111)
sensing mechanism
adsorption
pt-al2o3
infrared-spectroscopy
MISiC
platinum oxide
hydrogen
ftir spectroscopy
CO