Ionic Liquid‐Driven Engineering of Oxygen‐Deficient CeO ₂ Nanorods for Enhanced Cyclohexane Oxidation via Dynamic Hydroxyl Interfaces

Abstract Customizable metal oxides represent a promising class of catalysts for the selective oxidation of alkanes, where the interfacial active oxygen species often play a decisive role in determining catalytic performance. However, precise control over both surface and intrinsic oxygen vacancies (O v ), particularly on specific crystallographic facets, remains a significant challenge. In this study, we report a novel ionic liquid (IL)‐assisted etching strategy to fabricate CeO 2 nanorods with tailored O v structures, specifically engineered for efficient cyclohexane oxidation under mild conditions. The IL treatment modulates surface hydroxyl groups and generates abundant O v , thereby significantly enhancing the activation of cyclohexane. The catalytic activity of IL‐etched catalyst is significantly enhanced under 110 °C, and the conversion increases by 9.1 time. In situ spectroscopic and DFT analyses revealed that surface hydroxyl groups, particularly those associated with oxygen‐deficient sites, are crucial for promoting cyclohexane oxidation. Aberration‐corrected scanning transmission electron microscopy (AC‐STEM) further visualizes the localization of these active hydroxyls at defect‐rich regions. This work provides an interfacial engineering strategy for designing high‐efficiency metal oxide catalysts for selective alkane oxidation under energy‐efficient, low‐temperature conditions.