Precisely Tailoring Heterometallic Polyoxotitanium Clusters for the Efficient and Selective Photocatalytic Oxidation of Hydrocarbons.

ABSTRACT

Photocatalysis is a promising yet challenging approach for the selective oxidation of hydrocarbons to valuable oxygenated chemicals with O2 under mild conditions. In this work, we report an atomically precise material model to address this challenge. The key to our solution is the rational incorporation of Fe species into polyoxotitanium cluster to form a heterometallic Ti4 Fe1 cocrystal. This newly designed cocrystal cluster, which well governs the energy and charge transfer as evidenced by spectroscopic characterizations and theoretical calculations, enables the synergistic process involving C(sp3 )-H bond activation by photogenerated holes and further reactions by singlet oxygen (1 O2 ). Remarkably, the cocrystal Ti4 Fe1 cluster achieves efficient and selective oxidation of hydrocarbons (C5 to C16 ) into aldehydes and ketones with a conversion rate up to 12 860 µmol g-1 h-1 , 5 times higher than that of Fe-doped Ti3 Fe1 cluster. This work provides insights into photocatalyst design at atomic level enabling synergistic catalysis.