The Knoevenagel condensation reaction is one of the most important reactions in the industry for the synthesis of organic materials, medicinal, and biological compounds. In this work, we have proposed an original and efficient solid-base catalytic system for the Knoevenagel condensation reaction. For the first time, a mixed oxide catalyst derived from hydrotalcite-like SrCaAl precursor was synthesized by co-precipitation method and subsequently calcined for 5 h at 850 °C. The catalysts were characterized by various techniques. The SrCaAl mixed oxide was also compared with the usual CaAl sample in terms of structural characteristics and catalytic activity in the Knoevenagel reaction between active methylene compounds and benzaldehyde. The findings revealed that the SrCaAl mixed oxide sample is considerably active in this reaction compared to the CaAl sample due to its stronger basicity. The kinetics of the Knoevenagel condensation reaction over the SrCaAl catalyst was investigated and indicated that it follows from the second-order model. The stability and reusability of the catalyst sample were studied and it was found that the SrCaAl catalyst has high stability and a good lifetime. The effects of reaction time, amount of catalyst, and reaction temperature on benzaldehyde conversion (%) and product selectivity (%) were assessed in this study using the Box-Behnken design. The appropriateness of the quadratic regression model was evaluated through the ANOVA method. Under optimal conditions, the conversion percentage of benzaldehyde and product selectivity reached 97% and 84%, respectively.

中文翻译：

---

由LDH前体衍生的SrCaAl混合金属氧化物作为Knoevenagel缩合反应的新型高效固体碱催化剂：多元优化研究

Knoevenagel 缩合反应是有机材料、药物和生物化合物合成工业中最重要的反应之一。在这项工作中，我们提出了一种用于克诺文格尔缩合反应的原创且高效的固体碱催化体系。首次采用共沉淀法合成了类水滑石SrCaAl前驱体衍生的混合氧化物催化剂，并在850℃下煅烧5小时。通过各种技术对催化剂进行了表征。还比较了 SrCaAl 混合氧化物与普通 CaAl 样品的结构特征以及活性亚甲基化合物与苯甲醛 Knoevenagel 反应中的催化活性。研究结果表明，与 CaAl 样品相比，SrCaAl 混合氧化物样品由于其碱性更强，因此在此反应中具有相当大的活​​性。研究了 SrCaAl 催化剂上 Knoevenagel 缩合反应的动力学，并表明它遵循二阶模型。对催化剂样品的稳定性和重复使用性进行了研究，发现SrCaAl催化剂具有较高的稳定性和良好的寿命。本研究使用 Box-Behnken 设计评估了反应时间、催化剂用量和反应温度对苯甲醛转化率 (%) 和产物选择性 (%) 的影响。通过方差分析方法评估二次回归模型的适当性。在最佳条件下，苯甲醛的转化率和产物选择性分别达到97%和84%。