Hydroxyl-Induced Electronic Structure and Electron Transfer for Improved N2O Decomposition Activity of Co3O4

Abstract

Hydroxyl groups (−OH) were loaded on the surface of Co₃O₄ through hydrothermal treatment, which enhanced the electron transfer process at the gas–solid interface and the N₂O decomposition performance. Hydrothermal treatment does not substantially alter the crystal structure or oxygen vacancy content of the Co₃O₄ catalyst, while it slightly suppresses the BET surface area and reducibility. These factors do not primarily contribute to the enhanced N₂O decomposition activity of Co₃O₄. The −OH content peaks at 8 h of hydrothermal treatment, correlating with the highest catalytic activity. Electronic structure analysis reveals that the −OH groups raise the d-band center and narrow the band gap, thereby facilitating N₂O adsorption and electron transfer. DFT simulations support these findings, indicating that −OH groups enhance electron transfer from Co to N₂O, promoting N–O bond cleavage and lowering the activation barrier. This work provides an in-depth exploration of the mechanism by which hydroxyl groups facilitate electron transfer processes, offering fundamental insights into catalytic science and providing guidance for new catalyst design.