Clean Synthesis of Benzoic Acid by Catalytic Oxidation of Benzaldehyde

Using hydrogen peroxide as an oxidant, and Na2WO4 · 2H2O as catalyst to catalyze the oxidation of benzaldehyde to benzoic acid, NaHSO4· H2O( n (Na2WO4 · 2H2O): n ( NaHSO4 ·H2O ) = 1:1) as the promoter was chosen, and the effect of reaction time and catalyst dosage on the yield of benzoic acid were studied. The product is determined by melting point and infrared spectrometry. The best reaction conditions is: the mole ratio of n (benzaldehyde)/n (Na2WO4 ·2H2O)/n (additive)/n(hydrogen peroxide) = 100:1 : 1 :250, refluxing 5 h. Furthermore, the best additive is p - toluenesulfonic acid through the observation of 23 kinds of additives. Under the best reaction reaction conditions, the yield of benzoic acid can get 84.05% .