Toward Selective Photocatalytic Conversion of Methane to Methanol by a Colloidal Quantum Dot: Spatio-Temporal Reaction Control and in Situ Methanol Protection Schemes

We aim to achieve spatio-temporal control of the complex partial oxidation of methane by designing a nanoscale, confined diffusion-reaction system triggered by fast photo-induced electron and energy transfer events. The long-term goal of the proposed work – controlled room-temperature transformation of methane to methanol under ambient conditions, through fundamental knowledge of reaction mechanisms and control of the microscopic reaction environments – would be a revolutionary step in solar photochemistry. In the three years designated for the proposed work, we will (i) design a QD-ligand complex to adsorb methane in a distorted geometry to lower the energy barrier for H-atom abstraction, (ii) demonstrate the use of QDs to photo-generate high-energy species (1*O2, OH•, S1-) to perform H-atom abstraction from methane by photo-induced electron or energy transfer and (iii) design ligands for the QD that will chemically protect the target product methanol through reversible acetal formation, shuttle methanol away from the “reaction zone” at the QD surface, and release the methanol into bulk solution. In this way, we will selectively terminate the methane oxidation reaction at methanol.