Novel Hybrid Catalyst for Eco-Conscious CO ₂ Chemical Fixation via Cycloaddition: Zinc Complex on Base-Modified MCM-48

The development of novel and efficient catalysts is an important theme in heterogeneous catalysis from both fundamental and applied research perspectives. The combustion of fossil fuels, the primary source of energy used today, contributes not only to energy problems but also to ocean acidification and global warming. The fixation of CO2 into value-added chemicals has become an extensive research topic in the scientific community. This study presents a novel approach through the development of a zinc complex immobilized on a base-functionalized mesoporous MCM-48 material, which enhances the activity of carbon dioxide utilization via cycloaddition of CO2 to epoxide. In this study, a zinc complex containing 2,9-dimethyl-1,10-phenanthroline and zinc chloride was synthesized and characterized using powder XRD. When this combination was anchored on a base-functionalized MCM-48 material, it demonstrated efficient catalytic activity for the utilization of carbon dioxide. The structure, phase integrity, shape, thermal stability, and presence of functional groups were determined using various analytical techniques, such as powder XRD, N2 adsorption–desorption, FT-IR, SEM, NMR, and thermogravimetric analysis. The resulting hybrid material was employed to chemically convert carbon dioxide to cyclic carbonates. Owing to the contributions from both the amine groups and the mononuclear zinc complex grafted onto the mesoporous surfaces, the catalytic performance of the hybrid material as a catalyst was found to be superior. A 93% conversion with 90% selectivity was achieved using a zinc complex immobilized on a base-functionalized MCM-48 material. The novelty of this work lies in the design of a zinc complex-immobilized mesoporous structure, providing the unique structural and electronic synergy between the Zn complex and the 3D ordered mesoporous support. This approach showed high catalytic efficiency for a solvent-free, cocatalyst-free hybrid system in CO2 utilization.