Promotional Effects of CeO2 on Stability and Activity of CaO for the Glycerolysis of Triglycerides

Glycerolysis of triglycerides (corn oil) was carried out over CeO2 promoted CaO catalysts. CeO2 was introduced into CaO via the sol-gel combustion method with citrate as the precipitator. A strong interaction between CaO and CeO2 was revealed by XRD, XPS and Raman results, which results in an increased basic strength and amounts of strong basic sites. Moreover, the lixiviation of CaO in the glycerol at high temperature, which is the key problem in the glycerolysis reaction over CaO-based catalysts, was inhibited significantly. XRD, N-2 adsorption-desorption isotherms and SEM results exhibit introducing CeO2 increases the surface area, pore volume and pore size of CaO catalysts, which are beneficial to the catalytic activity. The 2CaO-1CeO(2) catalyst with strong basicity and large surface area achieved over 90 % conversion after 1 h while the lixiviated Ca decreased dramatically.