A Research On Nitration Of Toluene Catalyzed By Solid Superacid SO₄～(2-)/TiO₂-La～(3+)

p-nitrotoluene is an important intermediate and material for the chemical, medication and pesticide industry. Though the supply of 0-nitrotoluene quite exceeds its demand in the market, the supply of p-nitrotoluene is relatively insufficient. Toluene is widely used as raw material in industries to produce p-nitrotoluene, with the mixed acid made of strong sulfuric acid and thick nitric acid as the catalyst for the nitration reaction. But the produce by this method is mainly 0-nitrotoluene and the use of strong sulfuric acid and thick nitric acid will undoubtedly cause severe erosion of instruments and environmental pollution; besides, it is quite hard to deal with the waste acid after the reaction.In the research experiment described in this paper, the author produces by herself rare earth solid Superacid SO₄^2-/TiO₂-La³⁺ and uses it as the catalyst for the nitration reaction of toluene, and gets satisfactory result.1. Make at first the catalyst of SO₄^2-/TiO₂-La³⁺in this way: first make metallic oxide of TiO₂ by precipitator method, then drying it in the oven at 100℃, then get TiO₂ powder by sifting it through a 100 mesh sift. After that, dissolve a specified amount of La2O3 powder in the dilute solution of 1.0 mol.L-1 diluted sulfuric acid; then put a specified amount of TiO₂ powder into this mixed solution and filtrate it 3 hours later. Put it in a muffle after drying it under room temperature and bake it for 3 hours at 500℃, the solid super acid of SO₄^2-/TiO₂-La³⁺ can be made in this way.2. The acidity measured by the Hammet method is -16.02