Molecular-Ionic Hybrid Modulates Intermediate Evolution from CO2 to Methanol at High Current Density

Abstract

Electrochemical conversion of CO2 to methanol offers compelling route for sustainable carbon utilization. Although cobalt phthalocyanine (CoPc) is recognized as promising catalyst for this reaction, achieving high methanol selectivity at high current density remains a critical challenge, due to insufficient stabilization of *CO intermediate and sluggish hydrogenation kinetics. Here we report a molecular-ionic hybrid catalyst constructed by integrating amino-functionalized CoPc with imidazolium-based ionic liquid (IL) on carbon nanotubes (CoPc-NH2 + IL/CNT). The hybrid catalyst achieves a methanol Faradaic efficiency of 75.0% with a partial current density of 300 mA cm–2. This outstanding performance originates from the cooperative interplay between CoPc-NH2 and imidazolium cations. The imidazolium serves as a CO2 adsorption reservoir that enriches and delivers CO2 to Co centers for activation, while simultaneously inducing a more electron-deficient Co center that stabilizes diverse *CO adsorption states for deep hydrogenation. In parallel, imidazolium cations reorganize interfacial hydrogen-bond networks, accelerate water dissociation and proton supply, and facilitate charge transfer to reaction intermediates through an electronic relay effect. These synergistic effects suppress the competing CO pathway and selectively steer CO2 electroreduction toward methanol at high current densities. The effectiveness of this molecular-ionic coupling is further validated across a range of imidazolium cations, demonstrating the generality of this microenvironment-engineering strategy.