New Greener Method for the Preparation of Heteropolyacid Compounds (HPW) Modified with Metallic Tin and Application in the Lactic Acid Esterification Reaction

The main objective of this work was to design an innovative method prepare heterogeneous heteropolyacid catalysts. H3PW12O40 (HPW) modified with tin(II) by two methodologies: a conventional aqueous ion-exchange (CS) and redox solid-state (SS). In both cases, Fourier transform infrared spectroscopy (FTIR) X-ray diffraction (XRD) measurements evidenced that Keggin structure preserved. All materials were active in the esterification lactic acid several alcohols mechanism proposed. best results obtained for octanol benzyl alcohol, where higher conversion values obtained. catalytic activity (turnover frequency, TON) showed efficient performance prepared 4 h calcination (CS4h SS4h). However, catalyst SS accordance development environmentally friendly processes.