Enhanced Catalyst Activity of WO₃ Using Polypyrrole as Support for Acidic Esterification of Glycerol with Acetic Acid

Figure 1

FT-IR spectra of WO₃-Ppy PNCs with particle loadings of (a) pure WO₃, (b) 5, (c) 10, (d) 15, (e) 20 wt%, and (f) pure Ppy, respectively.