Catalytic oxidation of acetone and ethanol on a platinum wire

The current-voltage characteristics of a thin long platinum wire in air with acetone or ethanol small admixtures were obtained. Using the quadratic dependence of platinum resistance on temperature, the temperature-current dependences for the wire were calculated. At concentrations of combustible gas vapors above a certain value, these dependences show a hysteresis character. Using the assumption of acetone and ethanol complete oxidation on platinum, as a catalyst, and the first order of the oxidation reaction, temperature-current dependences was analysised. The temperature difference between the high and low-temperature stationary regimes of catalytic oxidation on the wire makes it possible to estimate the admixture concentration. As a result, the experimental dependence of the critical current value by catalytic ignition and extinction gas mixture on platinum on the admixture concentration was constructed. With its analytical description, it is possible to fairly accurately estimate the apparent values ​​of the activation energy and the pre-exponential multiplier for the oxidation reaction in a wide temperature range. A method of determining the kinetic parameters for the oxidation reaction based on the experimentally found parameters of degeneracy critical conditions is proposed.