Catalytic Reactions of DNT and TNT Molecules on Porphyrin Complexes

Reactions of molecules with substrates can be used to identify them, as in sensor applications. Here we examine reactions of DNT and TNT molecules on porphyrin and metal-porphyrin via first-principles DFT calculations. We find that the oxidation of DNT by O$_{2}$ using Fe-porphyrin as a catalyst is exothermic. The affinity of O$_{2}$ to Fe-porphyrin weakens the O$_{2}$ intramolecular bond, which lowers the oxidation reaction barrier is lowered by $\sim$1 eV. Substrate effects on this process are accounted for. One way to use this selective oxidation reaction for DNT/TNT sensor applications is to exploit the metal-semiconductor transition in thin-film VO$_{2}$ to detect the energy deposited by the exothermic reaction between the adsorbed molecules. This work was supported in part by DTRA grant HDTRA1-10-0047.