Development of effective cesium-based catalyst is important for methyl methacrylate (MMA) production via one-step aldol reaction. Herein, a kind of Cs/Zr-SiO₂ catalyst was prepared by sol–gel method and the acid-base properties and their balance could be controllably regulated. The influence of catalyst preparation conditions including Si/Zr ratio and water content on the structure and acid-base properties of Cs/Zr-SiO₂ was demonstrated, which consequentially affected catalytic performance. The formation of Si-O-Zr and Cs-O-Si structure was identified as the dominant Lewis acid and base sites and the acid site density can be enhanced by 1-fold when using sol–gel method. In addition, the MP conversion could reach 37 % with MMA selectivity of 85 % at the optimal condition. Kinetic studies revealed that the activation barrier on the modified 10Cs/Zr-SiO₂ exhibited the lowest activation energy of 110.9 kJ/mol. Besides the initial catalytic activity could still maintain after 800 h recycling, with single-pass life of 160 h.

中文翻译：

---

溶胶-凝胶法用 Zr 元素修饰 Cs/SiO2 通过一步羟醛缩合法生产甲基丙烯酸甲酯


开发有效的铯基催化剂对于通过一步羟醛反应生产甲基丙烯酸甲酯 （MMA） 非常重要。本文采用溶胶-凝胶法制备了一种 Cs/Zr-SiO₂ 催化剂，其酸碱性质及其平衡可以得到可控调节。证明了催化剂制备条件（包括 Si/Zr 比和含水量）对 Cs/Zr-SiO₂ 结构和酸碱性能的影响，进而影响催化性能。Si-O-Zr 和 Cs-O-Si 结构的形成被确定为主要的路易斯酸和碱位点，当使用溶胶-凝胶法时，酸位密度可以提高 1 倍。此外，在最佳条件下，MP 转化率可以达到 37%，MMA 选择性为 85%。动力学研究表明，改性的 10Cs/Zr-SiO₂ 上的活化势垒表现出最低的活化能，为 110.9 kJ/mol。此外，回收 800 h 后初始催化活性仍能保持，单程寿命为 160 h。