A Green Route to Methyl Formate from CO2-Derived Formamides over Solid Base Catalysts

Abstract

The transformation of CO2 and CO2-derived chemicals into high value-added chemicals is an important method for reducing CO2 emissions and achieving carbon neutrality. Methyl formate (MF) is a critical C1 building block in synthesizing a wide range of important chemicals, such as formic acid, ethylene glycol, and formamide methyl propionate. Here, we report a green route for the sustainable synthesis of MF from CO2-derived formamides via the alcoholysis reaction catalyzed by supported CaO solid bases. The CaO/MgO catalyst with 13.5 wt.% CaO exhibited higher alcoholysis reaction efficiency and achieved 94.5% conversion of N-formylmorpholine and 100% selectivity of MF in methanol at 120 °C. Based on the kinetic studies, characterization results of structural and basic properties (XRD, and TEM, CO2-TPD, etc.), we found that the density of strong basic sites is linearly related to the activity of alcoholysis reaction, and the higher the base density on these catalysts, the greater the reaction rate. This study presents a sustainable route for the synthesis of MF by using CO2-derived formamides and green methanol, and a promising strategy for producing more efficient solid alcoholysis catalysts of amides.