Fe–N–C Artificial Enzyme: Activation of Oxygen for Dehydrogenation and Monoxygenation of Organic Substrates under Mild Condition and Cancer Therapeutic Application

Developing highly efficient biomimetic catalysts that directly use O₂ as the terminal oxidant to dehydrogenate and monoxygenate substrates with high selectivity under mild conditions has long been pursued but rarely achieved yet. Herein, we report that heterogeneous Fe–N–C, which is commonly used as an electrocatalyst for oxygen reduction reaction, had unusual biomimetic catalytic activity in both dehydrogenation and monoxygenation of a series of organic molecules (∼100% selectivity) by directly using O₂. The Fe–N_x center was verified to be the active site that reductively activated O₂ by spontaneously generating specific reactive oxygen species (ROS) (¹O₂, O₂^•–, and H₂O₂). Aided by these ROS, under physiological conditions, the Fe–N–C was further successfully exampled to kill proliferative lung cancer cells. Fe–N–C had several striking superior features with respect to natural enzymes, classical heterogeneous nanozymes, and homogeneous artificial enzymes incapable of working under harsh conditions (extreme pH and high temperature), ease of separation and recycling, and direct use of O₂. It would open up a new vista of Fe–N–C as an artificial enzyme in biomimetic catalysis, ranging from fundamental simulation of oxidase/oxygenase metabolism to industrial oxidation processes and to disease treatment.