Ethanol properties effects on its reaction with Mo-doped SnO2 clusters: A gas sensor model

Abstract

The reaction of ethanol with pristine and Mo-doped SnO2 is computed and compared to experimental results. The comparison includes response, response time, and the effect of humidity. Adsorption and transition states are evaluated and used to calculate the reaction rate of ethanol with pristine and Mo-doped SnO2. The modified Evans–Polanyi principle is used to evaluate Gibbs free energy of transition, including its components enthalpy and entropy at the investigated doping percentages of Mo at 3, 5, and 7 mol%. The effect of humidity on the backward reaction of ethanol burning is discussed. The impact of the autoignition temperature of ethanol at 368 °C on the reaction rate is included for the first time for Mo-doped SnO2. The theoretical results show good agreement with the experiment. Mo-doped SnO2 shows high response, short response time, and stability towards ethanol that nominate the sensor for practical applications.

Keywords

• Mo-doping
• SnO2 cluster
• Ethanol gas sensor
• Density functional theory
• Transition state