Synthesis of dibutyl oxalate catalyzed by activated carbon supported tungstosilicic acid under microwave irradiation

Dibutyl oxalate was synthesized with oxalic acid and butyl alcohol as raw materials and activated carbon supported tungstosilicic acid as catalyzer under microwave irradiation.The factors influencing the synthesis were discussed.The results by orthogonal experiments showed that activated carbon supported tungstosilicic acid was an excellent catalyst for synthesizing dibutyl oxalate.If the dosage of oxalic acid was 0.05 mol,molar ratio of butyl alcohol to oxalic acid was 2.6:1,the quantity of catalyst was equal to 8.0 %(based on the total feed stock),microwave power was 325 W,microwave irradiation time was 10 min,the use level of water-carring agent cyclohexane was 8 mL.Under these optimum experimental conditions,the esterification ratio could reach 96.8 %.Moreover,the catalyst could be easily recovered and reused,and had characteristics of low cost,high catalytic efficiency,wide availability,easy operation,and environmental friendliness.