(367e) Nanostructured Catalytic Materials for Chemical Sensors

There is a critical need for microsensors capable of quantifying the concentration of target gases in multicomponent mixtures for environmental, control, health, and safety applications. New microsensors will require the precision and accuracy of laboratory scale analytical tools (gas chromatographs), while at the same time must be low cost, low power, fast response, and portable. Current microsensors that meet these needs, however, simultaneously do not provide sufficient chemical selectivity for applications that cannot tolerate false positive responses. We propose a new class of catalytic microsensors that couple nanostructured metal oxide catalysts to selectively oxidize only the desired analyte in multi-component process gas mixtures with thin film microcalorimeters to transduce the resultant temperature change into an electrical signal. This sensing approach is elegant in its simple principle, and can be applied to a wide range of processes by tuning the catalyst substrate. Current work on the development of mixed metal oxide catalysts for selective catalytic detection of CO in a reformed H2 fuel (also containing CO2, H2O, and trace hydrocarbons) for portable PEM fuel cell systems and for the catalytic detection of ethanol in liquid fuel vapors will be presented.