A Hot Wire Methane Sensor Resistant to Silicon and Sulfur Poisoning

Abstract

The invention discloses an anti-silicon poisoning anti-sulfur-poisoning hot wire methane sensor. The anti-silicon poisoning anti-sulfur-poisoning hot wire methane sensor comprises a catalytic element and a reference element which are arranged in a hot wire structure; the catalytic element comprises an active carbon particle carrier, and a SnO2 gas sensitive layer, a Pt / Pd catalyst, and an Al2O3 / SiO2 separation layer loaded on the active carbon particle carrier; the reference element comprises aluminum oxide small balls, and a conductive carbon black-doped SnO2-C / TiO2-C gas sensitive layer, an Au / CuO catalyst, and an Al2O3 / SiO2 separation layer loaded on the aluminum oxide small balls. With considering of preparation cost and ensuring of service life, the hot wire structure is adopted, and the problems of the SnO2 element on improving of methane detection sensitivity, linear output, selectivity, poisoning resistance, and stability are solved.

Description

technical field [0001] The invention relates to the manufacture of a hot-wire methane sensor that is resistant to silicon and sulfur poisoning, and is aimed at the detection of methane gas at industrial sites containing silicon and sulfur, and belongs to doped SnO 2 It is a kind of volume resistance control type semiconductor gas sensor. Background technique [0002] The detection principle of the metal oxide semiconductor gas sensor (Metal Oxide Semiconductor gas sensor, MOS) is: under certain conditions (temperature), the measured gas reaches the surface of the semiconductor and undergoes a chemical reaction with the oxygen adsorbed on the surface of the semiconductor. The charge transfer causes the change of semiconductor resistance, and the gas detection is realized by measuring the change of semiconductor resistance. [0003] Methane has a particularly stable tetrahedral structure, and the carbon-hydrogen bond energy is 412.5kJ / mol. Breaking the carbon-hydrogen bond re...

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Problems solved by technology

[0007] 3. No response to common gases in the monitoring environment, or the sensitivity is as low as possible, such as CO;

[0008] 4. For common interfering gases in the monitoring environment, the cross-sensitivity is low and stable, such as ethanol;

[0012] 1. The output signal is non-linear;

[0013] 2. Poor gas selectivity, and almost all reducing gases have gas-sensing properties, making the detection of methane susceptible to interference;

[0014] 3. Poor stability, susceptible to environmental temperature and humidity, long-term work has the problem of signal drift;

[0015] 4. No anti-silicon and anti-sulfur poisoning properties

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