Dimethyl carbonate synthesis over solid base catalysts derived from Ca-Al layered double hydroxides

摘要

The Ca-Al oxide catalysts are prepared via thermal decomposition of Ca-Al layered double hydroxide precursors and characterized by XRD, TG, SEM, BET, CO2-TPD, Hammett indicators, XPS and ICP techniques. The obtained catalysts are then tested for transesterification of methanol with propylene carbonate (PC), highest dimethyl carbonate (DMC) yield of 59.9% has been reached with methanol: PC molar ratio of 12, catalysts weight of 2 wt% total reactants, and reaction time of 2 h. Research results show that though the transesterification occurs over various basic sites, the strong basic site has a leading role on transesterification, which is consistent with the activity results. The catalysts can be recycled and the reason for the decrease in catalytic activity is further discussed in detail.