Partially Reduced PtO Promoted Activation of Oxygen and Ammonia for Ambient Photocatalytic Ammoxidation

Heterogeneous catalytic ammoxidation of hydrocarbons is the major process for the synthesis of nitriles, yet the demand on pressurized oxygen and elevated temperature to achieve a satisfactory yield causes serious concerns on safety, sustainability, and viability for the upgrade of molecules with fragile functional groups. The overall reaction is hampered by the slow dissociation of molecular oxygen in an ammonia environment that limits the formation of the aldehyde intermediate for consecutive steps. Here, we show that the partially reduced PtO serves as a promising cocatalyst supported on graphitic carbon nitride (PtO_1-x/CN) for the photocatalytic ammoxidation of aromatic alcohols under ambient air pressure at room temperature in aqueous ammonia. PtO_1-x displays a reduced activation of molecular oxygen and an optimum adsorption of atomic oxygen, thus facilitating the oxidation of alcohol to aldehyde. Meanwhile, the enhanced adsorption of NH₃ on PtO_1-x/CN promotes the formation of an imine intermediate and the consecutive oxidative dehydrogenation to yield nitrile. PtO_1-x/CN achieves high conversions and selectivities for the synthesis of aromatic nitriles from corresponding alcohols with excellent stability, featuring it as an economical and sustainable solution for applications.