Efficient synthesis of glycerol carbonate from glycerol and urea with lanthanum oxide as a solid base catalyst

Abstract

Lanthanum oxide catalyst prepared by precipitation method and calcined at 600 °C exhibited better catalytic activity in the catalytic synthesis of glycerol carbonate from glycerol and urea with TOF up to 1506 mmol/g·h. It was proposed that the lanthanum oxide catalyst with more strong basic sites (T d > 400 °C) exhibited higher catalytic activity. Accordingly, the catalyst containing appropriate amount of La 2 O 2 CO 3 phase exhibited higher catalytic activity. Moreover, the recycling experiments demonstrated that the catalytic activity can be essentially preserved during the recycling tests investigated. Lanthanum oxide catalyst prepared with precipitation method and calcined at 600 °C exhibited 89.1% of glycerol carbonate yield with 98.6% selectivity with as low as 1 wt.% catalyst amount in glycerolysis of urea, thereby leading to higher TOF of 1506 mmol/g·h as compared to the previous report. ► A series of rare earth oxides was tested in the carbonylation of glycerol with urea. ► Lanthanum oxide exhibited better catalytic activity in glycerol carbonate synthesis. ► The catalytic activity essentially correlated with the strong basicity (T d > 400 °C).