Magnesium–aluminum hydrotalcite (HT) supported gold catalyst (1 wt% Au/HT) was prepared by the colloid-deposition method and characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Hammett indicator method. The effects of calcination temperature of catalyst and support on the catalytic performance of aerobic oxidative esterification of 1,3-propanediol with methanol to methyl 3-hydroxypropionate (3-HPM) under base-free condition were studied. The results showed that the conversion of 1,3-propanediol and the selectivity of 3-HPM increased first and then decreased with the increase of calcination temperature of catalyst and support. The optimal calcination temperature of catalyst and support is 150 °C. Under the optimum preparation conditions, the conversion of 1,3-propanediol and the selectivity to 3-HPM are 96.2% and 94.9%, respectively. In addition, the 1 wt% Au/HT catalyst could be effectively recovered by calcining at 150 °C in air atmosphere, and the performance of the catalyst does not decrease significantly. The performance of the catalyst is higher than that reported previously. The structure of magnesium–aluminum hydrotalcite with appropriate density and medium strength base sites and small metallic Au particles are favorable for the selective oxidative esterification of 1,3-propanediol to 3-HPM.

Graphic abstract

A 1 wt% magnesium–aluminum hydrotalcite supported gold catalyst (1 wt% Au/HT) was prepared by the colloid-deposition method. The calcination temperature plays an important role for the catalytic performance and the higher catalytic activity and product selectivity is due to the synergistic effect between the support structure with appropriate density and medium strength base sites and the smaller metallic gold particles.

中文翻译：

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煅烧温度对碱位和金纳米粒子协同催化水滑石负载金材料1, 3-丙二醇与甲醇无碱氧化酯化制备3-羟基丙酸甲酯的影响

通过胶体沉积法制备镁铝水滑石 (HT) 负载的金催化剂 (1 wt% Au/HT)，并通过电感耦合等离子体原子发射光谱 (ICP-AES)、X 射线衍射 (XRD)、氮吸附、透射电子显微镜 (TEM)、X 射线光电子能谱 (XPS) 和哈米特指示剂法。研究了催化剂和载体的煅烧温度对1,3-丙二醇与甲醇在无碱条件下好氧氧化酯化制3-羟基丙酸甲酯(3-HPM)催化性能的影响。结果表明，随着催化剂和载体煅烧温度的升高，1,3-丙二醇的转化率和3-HPM的选择性先升高后降低。催化剂和载体的最佳煅烧温度为 150 °C。在最佳制备条件下，1,3-丙二醇的转化率和3-HPM的选择性分别为96.2%和94.9%。此外，在空气气氛中在150℃下煅烧可以有效回收1wt%的Au/HT催化剂，催化剂的性能没有明显下降。该催化剂的性能高于先前报道的性能。镁铝水滑石的结构具有适当的密度和中等强度的碱位和小的金属金颗粒，有利于 1,3-丙二醇选择性氧化酯化为 3-HPM。在空气气氛中在 150 ℃下煅烧可以有效回收 1 wt% Au/HT 催化剂，并且催化剂的性能没有显着下降。该催化剂的性能高于先前报道的性能。镁铝水滑石的结构具有适当的密度和中等强度的碱位和小的金属金颗粒，有利于 1,3-丙二醇选择性氧化酯化为 3-HPM。在空气气氛中在 150 ℃下煅烧可以有效回收 1 wt% Au/HT 催化剂，并且催化剂的性能没有显着下降。该催化剂的性能高于先前报道的性能。镁铝水滑石的结构具有适当的密度和中等强度的碱位和小的金属金颗粒，有利于 1,3-丙二醇选择性氧化酯化为 3-HPM。

图形摘要

通过胶体沉积法制备了 1 wt% 镁铝水滑石负载的金催化剂 (1 wt% Au/HT)。煅烧温度对催化性能起着重要作用，较高的催化活性和产物选择性是由于具有适当密度和中等强度基点的载体结构与较小的金属金颗粒之间的协同作用。