The catalytic ozonation of VOCs is a promising approach for degradation of indoor VOCs, such as gaseous toluene. However, the mechanism and relevant kinetic steps involved in this reaction remain unclear. In this study, the catalytic ozonation of toluene over MnO₂/graphene was investigated using the empirical power law model and classic Langmuir-Hinshelwood single-site (denoted as L-H_s) mechanism. The apparent activation energy determined using the power law model was 29.3 ± 2.5 kJ mol⁻¹. This finding indicated that the catalytic ozonation of toluene over MnO₂/graphene was a heterogeneous reaction, and the Langmuir-Hinshelwood mechanism was applicable. However, the L-H_s mechanism did not fit the experimental data, suggesting that the reaction was non-single-site governed. A novel Langmuir-Hinshelwood dual-site (denoted as L-H_d) mechanism was then proposed to explain the experimental observations of the catalytic ozonation of toluene over MnO₂/graphene through a steady-state kinetic study. This mechanism was based on the hypothesis that MnO₂ was responsible for ozone decomposition and toluene adsorption on graphene; these two types of adsorption were coupled by an adjacent attack. Furthermore, XPS results confirmed the presence of a strong connection between MnO₂ and graphene sites on the surface of MnO₂/graphene. This connection allowed the adjacent attack and validated the dual-site mechanism. The L-H_d model was consistent with the predicted reaction rate of toluene removal with a correlation coefficient near unity (r² = 0.9165). Moreover, the physical criterion was in accordance with both enthalpy and entropy of toluene adsorption constraints. Fulfillment of mathematical and physical criteria indicated the catalytic ozonation of toluene over MnO₂/graphene can be well described by the L-H_d mechanism. This study helps understand the catalytic ozonation of toluene over MnO₂/graphene in a closely mechanistic view.