Synergistic Interactions between Ti–OOH and (PO4[WO2(O2)]4)3- of HPW/Zn-Ti Hydrotalcites: Efficient Heterogeneous Catalysts for the Epoxidation of Fatty Acid Methyl Ester

Abstract

A series of HPW/Zn-Ti layered double hydroxides (LDHs) were prepared by immobilizing phosphotungstic acid (HPW) on the Zn-Ti LDHs. Systematically characterizations were performed to elucidate their structure. These HPW/Zn-Ti LDHs hybrids were used as heterogeneous catalysts in the epoxidation of fatty acid methyl ester (FAMEs) with H 2 O 2. The HPW/Zn-Ti LDHs showed higher activity than bulk HPW and Zn-Ti LDHs. The conversion of FAMEs and the selectivity to epoxy fatty acid methyl ester (EFAME) were up to 90.6 and 86.0%, respectively. (PO 4 [WO 2 (O 2)] 4) 3was presumed to be the active site for the epoxidation in this work. The formed oxygen-donating intermediate Ti−OOH transferred oxygen free radicals to (PO 4 [WO 2 (O 2)] 4) 3in the catalytic process, accelerating the transfer of oxygen free radicals. Therefore, high catalytic activity of HPW/Zn-Ti LDHs is related to the potential synergistic interactions of Ti−OOH and PW anions.

Controllable Acid/Base Propriety of Sulfate Modified Mixed Metal Oxide Derived from Hydrotalcite for Synthesis of Propylene Carbonate

“…Encouraged by the preceding achievements, herein, we report the synthesis of PC from 1,2-propylene glycol (PG) and urea by constructing the mixed metal oxide derived from hydrotalcite catalysts with controllable acid/base properties [23][24][25][26]. The catalysts were prepared from the ammonium persulfate modification of MgAl-hydrotalcites [27].…”