Abstract Transesterification of propylene carbonate (PC) and ethanol is a potent non-phosgene route for the synthesis of diethyl carbonate (DEC). In the present study, hydroxyapatite was synthesized and modified using Zn and Mg (Zn/HAP and Mg/HAP). Modified hydroxyapatite was used as catalyst for the synthesis of DEC. The thermal analysis of the catalytic precursor was studied using thermogravimetric-differential thermal analysis. The structural analysis, surface morphology, and nature of active sites over the catalyst surface were studied using techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and CO2 temperature-programmed desorption. Effects of reaction conditions like reaction temperature, reaction time and ethanol/PC molar ratio on DEC yield were also studied. The effects of Mg and Zn on HAP were found to be promotional for the synthesis of DEC using PC and ethanol. Mg/HAP was found to be the best among the three catalysts studied owing to its high basicity. Maximum DEC yield of 52.1 % was obtained in 5 h at 433 K using Mg/HAP catalyst.

中文翻译：

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镁、锌促进羟基磷灰石酯交换反应高效合成碳酸二乙酯

摘要 碳酸亚丙酯 (PC) 和乙醇的酯交换是合成碳酸二乙酯 (DEC) 的一种有效的非光气途径。在本研究中，使用 Zn 和 Mg（Zn/HAP 和 Mg/HAP）合成和改性羟基磷灰石。改性羟基磷灰石用作合成DEC的催化剂。使用热重-差热分析来研究催化前体的热分析。使用傅里叶变换红外光谱、X 射线衍射、N2 吸附-解吸、扫描电子显微镜和 CO2 程序升温解吸等技术研究了催化剂表面活性位点的结构分析、表面形态和性质。还研究了反应温度、反应时间和乙醇/PC摩尔比等反应条件对DEC产率的影响。发现 Mg 和 Zn 对 HAP 的影响可促进使用 PC 和乙醇合成 DEC。由于其高碱度，Mg/HAP 被发现是所研究的三种催化剂中最好的。在 433 K 下使用 Mg/HAP 催化剂在 5 小时内获得了 52.1% 的最大 DEC 产率。