When it passed over the surface of TiO₂-Y₂O₃ with the mass ratio of 3∶1, methanol gas was catalytically oxidized by O₂ in air that resulted in intensive chemiluminescence (CL). A novel methanol gas sensor based on this kind of CL was developed. The results showed that the sensor was of high sensitivity and selectivity to the determination of methanol gas. Quantitative analysis was performed at the wavelength of 490 nm. Under the optimized conditions, the linear range of cataluminescent (CTL) intensity versus concentration of methanol vapor was from 25.74 to 12870 mg/m³ (r＝0.9995, n＝8), with a detection limit of 8.58 mg/m³ (the signal-to-noise ratio was 3). No interference signals were observed while the added substances passed through the sensor, such as cyclohexane, n-hexane, chloroform, benzene, ethanol, formaldehyde, acetone, ammonia and toluene, except acetone, ethanol and ammonia. The gas sensor could be working for more than 80 h and showed the longevity and steady performance and was applied to the online determination of methanol successfully.

Key words: cataluminescence, methanol, gas sensor, TiO₂-Y₂O₃ powder