One-pot conversion of CO2 and glycerol to value-added products using propylene oxide as the coupling agent

Abstract

The effective conversion of carbon dioxide (CO₂) and glycerol is an interesting topic in green chemistry. In this work, we studied the simultaneous transformation of CO₂ and glycerol to value-added products using propylene oxide (PO) as coupling agent catalyzed by alkali metal halides. The effects of reaction temperature, CO₂ pressure, reaction time, amount of catalyst, and PO to glycerol molar ratio on the reaction were investigated. It was discovered that the coupled catalytic reaction could produce glycerol carbonate (GC), propylene glycol (PG) and propylene carbonate (PC) very effectively using KI, an abundant and cheap salt, as the catalyst. The main reasons are that glycerol and PG are not only the reactant and product, respectively, but also act as the effective co-catalysts to promote the key step of the coupled reaction, and the reaction is thermodynamically favorable. This effective and atom economic route to convert glycerol and CO₂ simultaneously has great potential application.