Preparation and characterization of Cu-formate heterogeneous catalysts from ash of gelam wood (Melaleuca leucadendron) for glycerol oxidation

ABSTRACT The conversion of glycerol into high-value-added chemicals has begun to take the attention of researchers in recent years. Approximately 10% (w/w) of glycerol is produced as a by-product in the manufacture of biodiesel. Through a catalytic oxidation reaction, glycerol can be converted to formic acid. In this study, glycerol was converted to formic acid as the main product by involving a heterogeneous catalyst of Cu-formate which was embedded in the ash of gelam wood (Melaleuca leucadendron). The catalyst was made with variations in the ratio of Cu-formate to gelam wood ash (GWA) = 0.125; 0.25; 0.50; and 0.75 (w/w). The catalysts were characterized by FTIR, XRD, SEM-EDX, and SAA. The Cu-formate/GWA catalyst was then tested for its activity on glycerol oxidation with various catalyst ratios, amount of catalyst (0.5–3% (w/w)), reaction temperature (50°−90°C), and reaction time (1–11 hours). The results showed that the yield of the products increased with increase in catalyst ratio. The optimal amount of catalyst was used at a concentration of 2% (w/w), a reaction temperature of 70°C, and a reaction time of 3 hours. GRAPHICAL ABSTRACT