Study On Nitration Of Chlorobenzene With Dinitrogen Pentoxide

For nitration of chlorobenzene, industry largely relies upon early technology involving mixtures of nitric acid and sulfuric acid. However there were many disadvantages: low selectivity, cauterization to the equipment, causing pollution in mixed-acid nitration. And so using dinitrogen pentoxide as new nitric reagent and solid acid for the nitration of chlorobenzene was one of the technologies for rising green chemical synthesis.In this paper, HZSM-5 molecular sieve and heteropoly acid H₄SiW₁₂O₄₀,H₃PW₁₂O₄₀,H₃PMo₁₂O₄₀ were prepared and used as catalysts, dinitrogen pentoxide was used as nitration reagent. Various conditions to the reaction were optimized by unifactor and multifactor orthogonal experiment, such as reaction temperature, reaction time, the amounts of catalysts. And the solid acids were characterized by ways of FT-IR,XRD,NH₃-TPD,TG.. All the samples results were consistent with those in literatures. Under the optimum reaction condition that the nitration reaction time was 1 hour and the temperature was 50℃, transformation rate was 11%,the selectivity was 85.3%.While under the same conditions, transformation rate was 26% by using H₃SiW₁₂O₄₀/SiO₂, the selectivity was 80.1% by using H₃SiW₁₂O₄₀/HZSM-5.