Design of Amine-Modified Zr–Mg Mixed Oxide Aerogel Nanoarchitectonics with Dual Lewis Acidic and Basic Sites for CO2/Propylene Oxide Cycloaddition Reactions

The utilization of CO2 attracts much research attention because of global warming. The CO2/epoxide cycloaddition reaction is one technique of CO2 utilization. However, homogeneous catalysts with both Lewis acidic and basic and toxic solvents, such as DMF, are needed in the CO2/epoxide cycloaddition reaction. As a result, this study focuses on the development of heterogeneous catalysts with both Lewis acidic and basic sites for the CO2 utilization of the CO2/epoxide cycloaddition reactions without the addition of a DMF toxic solvent. For the first time, the Zr-Mg mixed oxide aerogels with Lewis acidic and basic sites are synthesized for the CO2/propylene oxide (PO) cycloaddition reactions. To further increase the basic sites, 3-Aminopropyl trimethoxysilane (APTMS) with -NH2 functional group is successfully grafted on the Zr-Mg mixed oxide aerogels. The results indicate that the highest yield of propylene carbonate (PC) is 93.1% using the as-developed APTMS-modified Zr-Mg mixed oxide aerogels. The as-prepared APTMS-modified Zr-Mg mixed oxide aerogels are great potential in industrial plants for CO2 reduction in the future.