P-Al/NaX结构和酸碱性位调控对甲苯甲醇侧链烷基化性能影响

采用水热法原位合成了P-Al/NaX催化剂，然后通过浸渍NaOH对其进行酸碱性调控，并探究了它在甲苯甲醇侧链烷基化反应中的催化性能。结合X射线衍射（XRD）、X射线光电子能谱（XPS）、N₂吸附-脱附等表征及催化活性数据发现，原位负载P、Al后，合成的磷铝硅酸盐（Na₁₃Al₂₄Si₁₃P₁₁O₉₆·H₂O）结构展现出较好的甲苯甲醇侧链烷基催化活性；随着NaOH负载量的增加，乙苯和苯乙烯的选择性呈先上升后下降的趋势，当负载质量分数为9%的NaOH时，苯乙烯选择性为45.84%，乙苯和苯乙烯的收率之和达到63.08%。这可能是由于NaOH的负载有利于催化剂表面碱性的提高和酸性的降低，而高的强碱性位和弱酸性位数量有利于甲苯甲醇侧链烷基化反应的进行。

Effect of P-Al/NaX Structure and Acid-Base Control on the Side-Chain Alkylation of Toluene with Methanol

P-Al/NaX catalyst was in-situ synthesized by hydrothermal method, and its acidity and basicity were controlled by impregnation of NaOH, and its catalytic performance for side-chain alkylation of toluene with methanol was tested. Combined with the characterizations of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N₂ adsorption-desorption, and the catalytic activity data, it was found that the structure of the synthesized Na ₁₃Al₂₄Si₁₃P₁₁O₉₆·H₂O showed good catalytic performance of side-chain alkylation of toluene with methanol after in-situ loading of P and Al. With the NaOH loading increasing, the selectivity of ethylbenzene and styrene increased first and then decreased. When the NaOH loading (mass fraction) was 9%, the selectivity of styrene was the highest (45.84%), and the total yield of ethylbenzene and styrene reached 63.08%. This may be because the loading of NaOH was conducive to the increase of the number of strong alkaline sites and weak acidic sites, and the high number of strong alkaline sites and weak acidic sites were conducive to the side chain alkylation of toluene with methanol.