Catalytic Filter for Continuous and Selective Ethanol Removal Prior to Gas Sensing

• DOI: 10.1021/acssensors.9b02572
• Publication Date: 2020-03-16T08:19:50Z
• Authors: Andreas T. Güntner; Ines C. Weber; Sotiris E. Pratsinis
• Keywords: 1502 Bioengineering; Ethanol; 3105 Instrumentation; 1507 Fluid Flow and Transfer Processes; 10265 Clinic for Endocrinology and Diabetology; Humans; 610 Medicine & health; 02 engineering and technology; 1508 Process Chemistry and Technology; 0210 nano-technology; Catalysis

Ethanol is a major confounder in gas sensing because of its omnipresence indoor air and breath from disinfectants or alcoholic beverages. In fact, most modern sensors (e.g., graphene, carbon nanotubes, metal oxides) are sensitive to ethanol. This challenging ethanol often present at higher concentrations than target analytes. Here, simple modular packed bed filter presented that selectively continuously removes (and other alcohols like 1-butanol, isopropanol, methanol) over critical acetone, CH4, H2, toluene, benzene 30–90% relative humidity. consists catalytically active ZnO nanoparticles (dBET = 55 nm) made by flame aerosol technology annealing. Continuous oxidation CO2 H2 was observed temperatures above 260 °C while below that, unwanted acetaldehyde formed. Most remarkably, up 185 ppm were removed exhaled preliminary tests with an alcohol intoxicated volunteer, as confirmed mass spectrometry. At the same time, almost 4 orders magnitude lower 0.025 ppm) acetone preserved. superior previous catalyst filters CuO, SnO2, Fe2O3) overlapping conversions related ZnO's surface basicity. The performance stable (±2.5% conversion variability) for, least, 21 days. Finally, when combined Si-doped WO3 sensor, effectively mitigated interference without compromising sensor's fast response recovery times. Such catalytic can be readily all sensors.