| Acid-base catalysis is an important part of catalysis fields. Solid superacid and solid superbase, which are developed in resent years, attract close attention of many researchers, because of high acidic and basic strength, high catalysis efficiency, no pollution to environment, and no corrosion to equipments, reusable and renewable property. SO42-/MxOy solid superacid andγ-Al2O3-NaOH-Na solid superbase are most representative and industrial valuable ones of acid-base catalysts. In this paper application of these two catalysts in organic synthesis was studied.The first part of this paper provides an overview of the development of solid superacid in resent years. The catalyst, which is involved in Chinese patent 'A granular solid superacid catalyst and the method of preparation', was characterized by the method of indicator, SEM, FT-IR and BET. The decomposition product of sulfate radical on the surface of catalyst was analyzed in order to determine the surface structure of solid superacid catalyst. The result of experiments shows that the acid strength H0≤-16.04, 10000 times of 100% H2SO4 (H0=-11.99), specific surface of powdery catalyst 198m2/g and average pore radii 36℃, specific surface of granule catalyst 224m2/g and average pore radii 82℃which is smaller than the carrier Al2O 3. The catalyst, which has high, microcrystalline structure, large and specific pore volume, has high catalytic activity. There are two kinds of structures in SO42-/MxOy solid superacid: the bridge type double co-ordinating structure and the chelate type double co-ordinating structure, the bridge type double co-ordinating structure giving SO3, the chelate type double co-ordinating structure giving SO2. The chelate type double co-ordinating structure plays more important part in catalytic activity.For the synthesis reaction of polylol ketal,1,4-dioxane, pentaerythritol fatty acid ester, SO42-/MxOy solid superacid has a satisfactory catalytic activity. With the catalyst amount wt% of raw material, after 3 hour, the yields of all can be over 90%, and the side reaction is dehydratio of polyol. Four polylol ketal cyclohexanone pentaerythritol ketal, acetophenone 1,2-propanediol ketal, cylohexanone ethylene ketal, acetophenone ethylene ketal were synthesized in this paper. With diglycol as raw material, reaction temperature 260 ?, feed ratio 0.4ml/min, 1,4-dioxane was synthesized in fixed bed reactor, and the yield can be up to 76.14%. With pentaerythritol and fatty acid as raw materia, mole ratio of fatty acid and pentaerythritol 5.6:1, catalyst amount 0.90% wt% of totle material, catalysis temperature 180?, after four hours, yield of pentaerythritol fatty acid ester can be up to 99.88%. Because of high catalytic activity, no corrosion to equipments, no pollution to environment, reusable and renewable catalyst, the methodology of solid superacid is the optimal choice of acidic catalytic reaction.In the second part of this paper, the development of solid superbase was summerized. Based on traditional solid superbaseγ-Al2O3-NaOH-Na,γ-Al2O3 carrier with large specific surface and specific pore volume was introduced in order to improve traditional preparation methodology, which uses carbonate and hydroxide as precusor. The catalyst, which has high catalytic activity, was obtained and characterized by the method of BET, FT-IR, SEM, XRD and so on. The result shows that the catalyst has higher catalytic activity than traditional solid superbaseγ-Al2O3-NaOH-Na, H0≥37, specific surface 142.52m2.g-1, specific pore volume 0.4ml/g. For the synthesis reaction of chalcone, cyclohexanone aldolization and biodiesel,γ-Al2O3-NaOH-Na solid superacid has a satisfactory catalytic activity. With hypnone and phenylaldehyde as raw material, amount of catalyst 7.5% wt% of material, mole ratio of hypnone and phenylaldehyde 1:1.1, reaction temperature 40℃, after 3 hours, the yield of chalcone can be up to 96.88%. With cyclohexanone as raw material, amount of catalyst 10% wt% of material, reaction temperature 190℃, after 3 hours, dimmer of cyclohexanone can be up to 85.66%. With animal oil and mathanol as raw material, mole ratio of mathanol and oil 9:1, amount of catalyst 2% wt% of oil, reaction temperature 70℃, after 3 hours, the yield of biodiesel can be up to 91.8%. The methodology of solid superbase has some industrial prospects, because of high catalytic activity, no corrosion to equipments, and no pollution to environment. |
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