Thermal benzene activation by 3d transition metal (Sc-Cu) oxide cations

Considering the importance and complexity of benzene oxidation on mineral oxide aerosol surfaces in the atmosphere, gas-phase 3d-transition metal oxide cations were used as models of active sites on mineral oxide aerosols to mimic the corresponding reactions. The various cations have been prepared by laser ablation and reacted with benzene in a linear ion trap reactor. Of the 103 systematically investigated cations, 39 clusters can oxidize benzene at room temperature. In addition to the adsorption channel, other five types of reaction channels were observed, including dehydrogenation of C₆H₆, charge exchange, hydrogen atom transfer, oxygen atom transfer, and the formation of C₆H₅O^[rad] radical, among which the first two pathways are prevalent and the formation of C₆H₆O⁺ cations has not been reported in literature. The insight into the benzene oxidation reactions derived from the gas-phase model systems is helpful to build a detailed picture of oxidative mechanisms of C₆H₆ and its derivatives over corresponding mineral oxide aerosols.