The atom-efficient production of glycerol carbonate via transesterification between dimethyl carbonate and glycerol over fluorinated Al2O3-ZrO2 solid solution catalysts with suitable acidic-basic property

Abstract

A series of Al2O3-ZrO2-nF solid solution catalysts (n was the F: Al atomic ratios) with Al: Zr molar ratio of 0.2, was fabricated by addition of varied amounts of (AlF6)3- into the ZrO2 via a co-precipitation method. To our delight, the acidic-basic properties of Al2O3-ZrO2-nF can be tuned by the change of n. Then, the role of acidic-basic sites was investigated for the glycerol carbonate (GLC) production from glycerol and dimethyl carbonate (DMC). Despite that the more basic samples exhibited higher reactivities compared to that of the more acidic ones, the cooperative effect between the acidic-basic pairs can enhance the catalyst activity strongly. So, the catalyst with F/Al= 1.0 can realize the quantitative and selective transformation of glycerol to GLC applying DMC/glycerol of 1:1 ratio with a GLC yield of 91.2%, owing to its appropriate acidic-basic property. Furthermore, the uniform solid solution structure can prevent the generation of free Al or F species, assuring the catalytic material an excellent stability. More importantly, several green parameters including process mass intensity, environmental factor and atom utilization were calculated to confirm the environmental and economic compatibility of the GLC synthesis over the model catalyst.