Magnesium stabilized 12-tungstophosphoric acid impregnated SBA-15 for selective monolaurin production

Abstract

The wetness incipient method was used for the incorporation of Keggin structured 12-tungstophophoric acid (HPW) onto the magnesium modified SBA-15. All the synthesized catalysts were then characterized using FTIR, XRD, TEM, NH3-TPD, and nitrogen adsorption-desorption analysis. The results obtained confirmed the successful synthesis of SBA-15 and the anchoring of HPW on the MgSBA-15. Based on the experimental findings, it was found that catalyst loaded with 30 wt.% HPW had the highest lauric acid conversion (49.82%) and monolaurin yield (29.20%) as compared to other loadings. By using 30 wt.% HPW/MgSBA-15, the highest lauric acid conversion (78.31%) and monolaurin yield (55.35%) was achieved at reaction conditions of 160 ℃, 3 wt.% catalyst loading, and 4:1 glycerol/lauric acid ratio after 6 h of reaction time. Lastly, the catalyst was highly stable as it can be reused up to two times under identical process parameters without significant change in lauric acid conversion (77%). Such results revealed the strong interaction between the HPW and its support through the magnesium bridge.

Keywords

• 12-tungstophosphoric acid
• Mesoporous SBA-15
• Magnesium bridging
• Reusability
• Characterization
• Parameter study