Channel Confinement Enables K Species with Rich Electrons in α‐MnO2 for Water Molecules Activation

Abstract

AbstractWater molecules are actively involved in many catalytic oxidation processes, which require the construction of highly active sites for their activation to accelerate the reaction rate, especially over non‐noble metal catalysts. Herein, K species is embeded into the natural 2*2 channel of α‐MnO2 by a hydrothermal coupled molten salt method, which would make these K species behave in an electron‐rich state and provide more electrons for the activation of water molecules. Compared with surface K modification (namely, the electron‐deficient K species), channel K confinement can lower the activation energy barrier of H2O dissociation on α‐MnO2 to generate hydroxyl species with more nucleophilic oxygen atoms, contributing to the superior HCHO catalytic oxidation activity with a fourfold enhancement. The internal relationship among the confined channel, K species, and catalytic performance is systematically elucidated at the molecular level. This work offers a new ion confinement method and opens up new avenues to construct electron‐rich metal sites with channel structures for the activation of water molecules.