Studies On The Nanometer Solid Superacid And Its Catalytic Esterification Reaction

In this dissertation ,we stated the recent development of nanometer solid superacids and their appliance in organic synthesis. The preparation of borneolacetate catalyzed by nanometer solid superacid and its reaction kinetics were studied. The synthesis of eight compounds ( borneol ester and isoborneol ester) and other esters catalyzed by nanometer solid superacids were also researched. In addition, we still analyzed the distinction of esterification yield of borneol ester and isoborneol ester. The particle size, surface area, changes of profile and acidity of nanometer solid superacids were mensurated and analyzed by TEM, BET, XRD, IR and acid indicator. The structures of the main products of every esterification reaction were characterized by IR, 1^H NMR, and (13)^HNMR spectra.Firstly, the structures, particle size, surface area, changes of profile and the acidity of nanometer solid superacids were determined and analyzed by IR, TEM, BET, XRD and acid indicator. We also preliminarily studied the catalytic mechanism of nanometer solid superacids.Secondly, using nanometer solid superacids as the catalyst, the esterification reaction of acetic acid and borneol could proceed smoothly, the yield was very high and it had good reaction preference. The effects of reaction time, reaction temperature, the molar ratio of borneol to acetic acid, the mass percent of rare earth oxide in carrier, the mol concentration of dipping solution, baking temperature and the use level of catalyst on catalytic activity of nanometer solid superacid were discussed. The optimal conditions of preparation of catalyst and the optimal reaction conditions were obtained. Furthermore, we investigated its reaction kinetics, using isolated method we gained the reaction order of acetic acid and borneol. We also obtained the activation energy of the reaction through assaying the reaction rate constant of two temperatures (T₁, T₂). At last, the reaction rate equation was acquired.Thirdly, on the basis of the optimal reaction conditions of synthesis of borneolacetate, using borneol , isoborneol, acetic acid, propionate, butyrate and isobutyric acid as the starting material and nanometer solid superacid (S₂O₈)^2-/ZrO₂ or (SO₄)^2-/ZrO₂-La₂O₃ as the catalyst ,a series of compounds ( borneol ester and isoborneol ester ) which had six new compounds were prepared. The difference of esterification yield of borneol ester and isoborneol ester was analyzed.Finally, pentyl acetate and benteine could be respectively synthesized by esterification reaction in the presence of nanometer rare earth composite solid superacids (SO₄)^2-/ZrO₂-Gd₂O₃ and (SO₄)^2-/ZrO₂-Nd₂O₃. The effects of reaction time, reaction temperature, the mol ratio of acid to alcohol and the use level of catalyst on esterification yield were discussed. In the end, we obtained their optimal reaction conditions.