磷钨酸铯改性介孔分子筛催化剂的合成及催化应用

用溶胶-凝胶方法合成并表征了磷钨酸铯改性的SBA-15介孔分子筛催化剂Cs2.5-TPA—SBA-15。XRD表征结果表明，当催化剂中磷的摩尔分数为0．88％时，Cs2.5-TPA—SBA-15仍保持介孔分子筛SBA-15的晶体结构；BET表征结果验证了介孔结构的存在；FTIR表征结果表明了Keggin结构的存在以及Cs2.5—TPA与分子筛之间化学作用的存在；TGA-DTA表征结果表明，Cs^＋的引入增加了催化剂的热稳定性。将Cs2.5-TPA-SBA-15应用于丙烯酸与叔丁醇的酯化反应，实验结果表明，与其它铯化学计量比催化剂相比，Cs2.5-TPA—SBA-15的酸催化活性最好。

SYNTHESIS AND CATALYTIC APPLICATION OF SBA-15 MODIFIED BY CESIUM PHOSPHOTUNGSTATE

Mesoporous molecular sieve SBA-15 containing cesium substituted tungstophosphoric acid (Cs_(2.5)-TPA-SBA-15)was synthesized by sol-gel method and characterized by XRD,BET,FT-IR and TGA-DTA techniques.It was validated by XRD and BET data that the initial well-ordered 2D hexagonal structure of SBA-15 crystal and mesoporous pore structure were preserved in the catalyst having a phosphorus mol percentage of 0.88%.The existence of Keggin anions and the chemical interaction between Cs_(2.5)-TPA and SBA-15 were confirmed by FT-IR spectrums.TGA-DTA results showed that the thermal stability of the catalyst was enhanced by the incorporation of cesium cations.The best result for esterification of acrylic acid and butyl alcohol was obtained over the catalyst having a molar ratio of cesium to phosphorus of 2.5.