Preperation of 2,4-Dinitrotoluene with NO_2

Dinitration of toluene by NO2/O2 in autoclave was studied. Effects of reaction conditions on the conversion of toluene,the yield of dinitrotoluene(DNT)and the ratio of 2,4-DNT to 2,6-DNT were investigated. The results show that Hβ presents good catalytic activity and regioselectivity in dinitration of toluene. The optimized temperature,pressure,time (for toluene dinitration) were 40 ℃,1.0 MPa,10 h respectively,and the molar ratio of NO2 to toluene was 3.5 in the presence of Hβ-CH3SO3H. Thus the conversion of toluene is 99.3%,the yield of DNT is 89.4% and the ratio of 2,4-DNT to 2,6-DNT is 33. Hβ is recovered by simple phase separation and has almost same catalytic activity after being reused for 4 times.