Predictive Analytical Modeling of Surface Adsorption Kinetics Governing the Response of Metal Oxide Gas Sensors

This work presents an analytical modeling framework for describing surface reaction kinetics in semiconductor metal oxide gas sensors used for the detection of carbon monoxide (CO) and nitrogen dioxide (NO 2 ). Nonlinear and linear rate equations governing adsorption and reaction processes on the sensor surface are solved to obtain explicit expressions for the concentrations of adsorbed oxygen species and reactive gases. The analytical solutions show excellent agreement with numerical simulations, confirming the validity of the proposed approach. Special cases, including oxygen adsorption without interference and oxidizing gas sensing such as NO 2 , are also examined. Sensitivity analysis reveals the influence of kinetic parameters on sensor conductance. An analytical relationship between surface oxygen coverage and local CO concentration is derived, providing a direct link between adsorption kinetics and measurable gas‐sensor response for improved sensor analysis and design.