Stanene is a predicted topological insulator that may display dissipationless currents at its edges near room temperature. It is composed of tin atoms arranged in a single layer, in a manner similar to graphene. Its buckled structure leads to high reactivity against common air pollutants such as NO x and CO x and it is able to trap and dissociate them at low temperature. A structure determination of stanene using low energy electron diffraction has shown ultra-flat stanene on a Cu(111) surface.