Rapid synthesis of dimethyl carbonate at room temperature catalyzed by a novel solid base 3-amino-1,2,4-triazole calcium†

Dimethyl carbonate (DMC) is a vital chemical compound with extensive applications, particularly as a solvent in lithium-ion battery electrolytes. In this study, a novel catalyst, 3-amino-1,2,4-triazole calcium [Ca(ATZ)₂], was synthesized, characterized, and applied for the efficient synthesis of DMC via the transesterification of ethylene carbonate (EC) and methanol. The catalyst demonstrated exceptional performance, achieving 73% EC conversion and 99% DMC selectivity under mild conditions (25 °C, 5 min). A unique feature of Ca(ATZ)₂ was its ability to transition from heterogeneous to homogeneous catalysis during the reaction. Initially, the reaction proceeded through heterogeneous catalysis, but as ethylene glycol (EG) was generated, the catalyst partially dissolved in EG, shifting to a homogeneous phase. This dual-phase mechanism significantly enhanced reaction efficiency. The effects of reaction conditions, alcohol structure, and catalyst reusability were systematically investigated, and a plausible catalytic mechanism was proposed. The results highlight the potential of Ca(ATZ)₂ as a sustainable and highly efficient catalyst for DMC production, offering a promising route for industrial applications. This work not only advances the field of catalytic chemistry but also contributes to the development of greener and more cost-effective chemical processes.