Newly discovered two-dimensional tin, named stanene, has been theoretically predicted and found to have unique electronic properties. Stanene is found to have a buckled structure which could be a key structure against chemical reactivity. Hence, the reactivity of stanene against key air pollutants NO, NO2, SO, SO2, CO, and CO2 is investigated within first principles calculations. The results showed that stanene is reactive against those air pollutants. Furthermore, the dissociation activation energies of those pollutants over stanene are lower than previously reported catalysts. The physical origin of low dissociation barriers rests in the charge transfer from stanene to those pollutants, resulting in bond weakening. Hence, one can predict that unique reactivities of stanene offer low temperature trapping and dissociation of air pollutants.