Ionic liquids (ILs), as a novel class of molecular platforms with structural tunability, play a significant role in the construction of functional composite materials. Their structural designability enables them to function not only as conventional solvents but also as synthetic media, pore modifiers, functional components, and structure-directing agents. The combination of ILs with reticular materials generates functionalized systems with synergistic effects. The introduction of ILs can modulate the pore architecture, chemical microenvironment, and stacking modes of reticular materials, endowing them with superior performance in catalysis, separation, and energy-related applications that surpass those of single-component materials. This review systematically summarizes the research progress on the application of ILs in reticular materials. First, the synthetic strategies and structure-regulation principles of IL/reticular material composites are analyzed. Second, the multifunctional roles of ILs in the synthesis of reticular materials—as solvents, templates, and structure-directing agents—are summarized. Subsequently, their application progress in CO₂ capture and conversion, catalysis, separation, and energy-related fields is systematically introduced. Finally, the challenges and future directions in this field are discussed. This review aims to provide a systematic theoretical reference for researchers working on porous materials, ionic liquids, and functional composites.

Ionic liquids (ILs), as structurally tunable and functionally diverse molecular platforms, offer unique advantages in the electrocatalytic reduction of carbon dioxide. With their wide electrochemical windows, high CO₂ solubility, and designable ion-pair structures, ILs function beyond conventional electrolytes or solvents. They can modulate the interfacial microenvironment, stabilize key intermediates, and suppress parasitic hydrogen evolution, thereby enhancing the catalytic efficiency and product selectivity. Recent advances have expanded IL applications into multifunctional electrocatalytic systems, including those coupled with light, electric fields, and pH stimuli. This review, structured around “structure–function–mechanism”, systematically summarizes the roles and regulatory strategies of ILs in CO₂ reduction reaction (CO₂RR). We compare the representative cationic frameworks, imidazolium, pyridinium, and quaternary ammonium, and analyze their effects on CO₂ activation and product distribution. The diverse roles of ILs as electrolytes, co-solvents, and catalyst modulators are discussed in detail. In situ characterization and theoretical simulations are highlighted for their insights into interfacial behavior and mechanistic understanding. Beyond electrocatalysis, the emerging integration of ILs into functional materials and hybrid systems is explored. Despite their promise, challenges such as high viscosity and limited mechanistic clarity remain. To address these issues, we propose a multidimensional optimization framework spanning molecular design, interfacial engineering, and system integration. This review aims to provide a comprehensive perspective on the strategic deployment of ILs in CO₂RR and to offer guidance for advancing efficient electrocatalytic systems toward carbon-neutral energy technologies.