3-Hydroxypropanal (3-HPA) is formed by the cross-aldol reaction of formaldehyde (HCHO) with acetaldehyde (CH₃CHO), which further converts to 1,3-propanediol (1,3-PDO). Mg/SiO₂ and X-5Mg/SiO₂ (X = Mn, Fe, Co, Ni) catalysts were prepared using the sol–gel method and characterized with XRD, BET, TEM, and NH₃- and CO₂-TPD methods. The 5Mg/SiO₂ showed higher activity in terms of the yield and selectivity due to its suitable basic and acidic density. The addition of Mn to the 5Mg/SiO₂ catalyst caused dispelling of weak basic sites but maintained strong basic sites, and the high CH₃CHO conversion was maintained. The increase of weak acidic sites contributed to the increase of 3-HPA selectivity for the 1Mn-5Mg/SiO₂ catalyst. The cross-aldol reaction of HCHO with CH₃CHO to produce 3-HPA more easily proceeded than the self-aldol reaction of CH₃CHO according to the reaction kinetic analysis. Furthermore, Raney nickel was successfully applied to the hydrogenation process of 3-HPA to 1,3-PDO with over 90% HPA conversion and 1,3-PDO selectivity.

中文翻译：

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交叉羟醛反应和甲醛与乙醛加氢合成1,3-丙二醇

3-羟基丙醛 (3-HPA) 由甲醛 (HCHO) 与乙醛 (CH ₃ CHO) 的交叉羟醛反应形成，乙醛进一步转化为 1,3-丙二醇 (1,3-PDO)。采用溶胶-凝胶法制备了Mg/SiO ₂和 X-5Mg/SiO ₂ (X = Mn, Fe, Co, Ni) 催化剂，并通过 XRD、BET、TEM 和 NH ₃ - 和 CO ₂ -TPD 方法对其进行了表征. 5Mg/SiO ₂由于其合适的碱性和酸性密度，在产率和选择性方面表现出更高的活性。在 5Mg/SiO ₂催化剂中添加 Mn 导致弱碱性位点的消除，但保持强碱性位点，高 CH ₃维持CHO转化。弱酸性位点的增加有助于提高 3-HPA 对 1Mn-5Mg/SiO ₂催化剂的选择性。根据反应动力学分析，HCHO与CH ₃ CHO的交叉醛醇反应生成3-HPA比CH 3 CHO的自身醛醇反应更容易进行_。此外，雷尼镍成功应用于3-HPA加氢制1,3-PDO，HPA转化率超过90%，1,3-PDO选择性高。