Synthesis,Characterization And Catalytic Properties Of Mesoporous Solid Superacid

S₂O₈2-/ZrO₂solid superacid was prepared by chemical precipitation method andprecipitated with NH₃H₂O solution of28%, reacted with Zr（NO₃）₄·5H₂O solution of10%, for0.5h,100℃of crystallization temperature,600℃of roasting temperature, dipping withS₂O₈（NH₄）₂of0.5mol/L for24h. then S₂O₈2-/ZrO₂solid superacid （SZ） was synthesized.Mesoporous phase solid superacid was synthesised respectively by cetyl three methylbrominated ammonium （CTAB） of cationic surfactants and sodium dodecyl sulfate （SDS） ofanionic surfactant for template.Cetyl three methyl brominated ammonium （CTAB） for template. under the betterconditions of n（Zr）:n（CTAB）=1.0:0.5, reaction for0.5h, crystallization at100℃, ecalcinationat600℃, dipping with S₂O₈（NH₄）2of0.5mol/L for24h. Mesoporous phase S₂O₈2-/ZrO₂solid superacid （SZ-1） was synthesizedSodium dodecyl sulfate （SDS） for template. under the better conditions of n（Zr）:n（CTAB）=1.0:0.5, reaction for0.5h, crystallization at100℃, ecalcination at600℃, dippingwith S₂O₈（NH₄）₂of0.5mol/L for24h. Mesoporous phase S₂O₈2-/ZrO₂solid superacid （SZ-2）was synthesizedThe samples were characterized by X-ray powder diffraction （XRD）, nitrogenadsorption-desorption （BET）, FT-IR spectroscopy, differential thermal analysis （TG/DTA）,Hammett acid strengh test method, X-ray spectrometry element analysis （EDS）, scanningelectron microscopy （SEM）, transmission electron microscopy （TEM） and so on.The results show that: BET specific surface area of SZ was121.20m²Â·g^-1with porevolume of0.1643cm³Â·g^-1and pore size of3.124nm，acid group content of SZ-1was19.384mmol/by Hammett; BET specific surface area of SZ-1was161.22m²Â·g^-1with porevolume of0.2344cm³Â·g^-1and pore size of3.232nm，acid group content of SZ-1was21.512mmol/by Hammett; BET specific surface area of SZ-2was155.41m²Â·g^-1with porevolume of0.2143cm³Â·g^-1and pore size of3.408nm, acid group content of SZ-2was20.837mmol/g by Hammett; and SZ-1have larger specific surface area than SZ-2, both ofsamples have characteristics of mesoporous structure, similar to worms structure, acid groupstrength （H₀） of PKa both between-13.8and-12.7. The probe of synthesis7-hydroxyl-4-methyl coumarin with m-dihydroxybenzene andethyl acetoacetate ethyl-3-oxo-butanoate, were studied to detect SZ-1and SZ-2of catalyticactivity. The results shows that SZ-1and SZ-2had the higher catalytic activity than SZ. Thenexamines the performance of repeated use of two kind catalysts. shown as follows: under thebetter conditions of m-dihydroxybenzene and ethyl acetoacetate ethyl-3-oxo-butanoate1:1, catalyst0.15g, reaction at150℃,for3h, SZ for contraste xperiment was89.22%. afterfive times the yield of SZ was69.63%. yield of SZ-1was94.26%, after five times the yield ofSZ-1was73.73%. yield of SZ-2was93.84%, after five times the yield of SZ-2was74.56%.