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The responses to eight kinds of alcohols including structural isomers were measured with a micro gas sensor of adsorption/combustion-type, which was operated by a mode of pulse heating for 0.2 s up to a desired temperature from 100 to 450 °C after adsorption at room temperature for 9.8 s. A large response peak was observed due to flash catalytic combustion of adsorbed molecules on Pd/γ-Al2O3 upon a sharp increase in sensor temperature by pulse heating. The integral sensitivity (the area of the response peak) increased with increasing the number of carbon atoms involved in the alcohol molecules. The response shape and more notably its differential profile were dependent on the molecular structure and chain length. From such different response profiles, it was possible to identify and quantify the eight kinds of alcohols examined. [Copyright &y& Elsevier]

Abstract: Recently, we developed a highly sensitive micro-gas sensor on a silicon micro-hot platform, which was operated by a pulse-heating mode. The gas-sensing was resulted from the flash combustion of the volatile organic molecules adsorbed on the catalytic sensing material during a non-heating period. In the present work, Pd-loaded mesoporous silica (Pd/m-SiO2) was used as an adsorption/combustion-type sensing material. The sensor showed a large response peak to toluene, which was much larger than that of the sensor using Pd/γ-Al2O3 catalyst. Thus, m-SiO2 can increase dramatically the sensitivity of this type of sensor. [Copyright &y& Elsevier]