Efficient Selective Catalytic Fixation of CO₂ into Epoxide to Form Cyclic Carbonates Using Sodium Aluminate Engineered Gamma Alumina Catalyst

Abstract

The anthropogenic carbon dioxide (CO2) fixation and various engineering strategies are gaining very significant attention because of the expansion of the net‐zero carbon environment in the atmosphere. Herein, we designed a sodium aluminate@γ‐alumina (NaAlO2@γ‐Al2O3) catalyst by a simple and facile precipitation and impregnation tactics. A series of different weight percentage NaAlO2@γ‐Al2O3 materials were successfully synthesized and well characterized by using advanced analytical and spectroscopic techniques such as TGA, XRD, FE‐SEM, TEM/HR‐TEM, FT‐IR, Raman, TPD, and XPS analysis. The NaAlO2@γ‐Al2O3 catalyst was employed as a competent catalyst for the CO2 fixation under atmospheric pressure reaction conditions. The catalytic activity results evidently revealed that the cycloaddition reaction successfully achieved 94% styrene oxide conversion and 93% selectivity, along with an 87% yield of the styrene carbonate at 120 °C for 6 h. Furthermore, we comprehensively examined the effect of different reaction parameters such as the effect of sodium aluminate amount, co‐catalyst amount, temperature, and time for CO2 fixation reaction. Additionally, different terminal and internal epoxides were tested under optimized reaction conditions and achieved moderate to excellent yield of the desired cyclic carbonate products. Interestingly, a plausible reaction mechanism was proposed for the styrene carbonate synthesis using NaAlO2@γ‐Al2O3 catalyst surface with the support of characterization and experimental results. Remarkably, the NaAlO2@γ‐Al2O3 catalyst could be easily recoverable and successfully recyclable up to six consecutive cycles without declining its initial catalytic activity along with stable structural and physicochemical properties.

Harnessing the Engineered 2D Triazine-Based Metal-Anchored Covalent–Organic Framework as a Catalyst for Selective Conversion of CO2 into Value-Added Products at Atmospheric Pressure

“…Among them, cycloaddition between CO 2 and epoxide to form the cyclic carbonate protocol is one of the 100% atom economy reactions . Cyclic carbonates have a wide range of applications in many sectors. , Earlier, efficient heterogeneous catalysts such as zeolites, silica, graphene oxide, metal or mixed metal oxides, , ionic liquids, porous organic polymers, metal–organic frameworks, covalent–organic frameworks (COFs), and so on reported for the same.…”