Kang Min, Zhou Hai, Tang Dajiang, Chen Xiaomei, Guo Ying, Zhao Ning
Department of Chemistry and Chemical Engineering, Zunyi Normal College Zunyi 563002 China
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences Taiyuan 030001 China
RSC Adv. 2019 Dec 20;9(72):42474-42480. doi: 10.1039/c9ra09642f. eCollection 2019 Dec 18.
Methyl -phenyl carbamate (MPC) is an important intermediate for the green synthesis of methylene diphenyl diisocyanate (MDI) as well as many other important products. In the present work, Zn/Al/Ce mixed oxides derived from hydrotalcite-like precursors were employed as effective and recoverable heterogeneous catalyst for MPC synthesis DMC aminolysis. Zn/Al/Ce hydrotalcite-like precursors prepared coprecipitation method and the resulting catalysts were characterized by means of XRD, BET, SEM and XPS. Strong interactions within the Zn/Al/Ce mixed oxides were observed the addition of appropriate amount of cerium. The mixed oxides containing 2.5% cerium showed high DMC aminolysis activity giving aniline conversion of 95.8%, MPC selectivity of 81.6% and MPC yield of 78.2%. Moreover, as a heterogeneous catalyst, it also exhibited superiorities of easy recovery and recyclable stability for MPC synthesis.
氨基甲酸甲酯（MPC）是二苯基甲烷二异氰酸酯（MDI）以及许多其他重要产品绿色合成的重要中间体。在本工作中，由类水滑石前驱体制备的Zn/Al/Ce混合氧化物被用作MPC合成（碳酸二甲酯氨解）的有效且可回收的多相催化剂。通过共沉淀法制备了Zn/Al/Ce类水滑石前驱体，并采用XRD、BET、SEM和XPS对所得催化剂进行了表征。通过添加适量的铈，观察到Zn/Al/Ce混合氧化物内部存在强相互作用。含2.5%铈的混合氧化物表现出较高的碳酸二甲酯氨解活性，苯胺转化率为95.8%，MPC选择性为81.6%，MPC产率为78.2%。此外，作为一种多相催化剂，它在MPC合成中还表现出易于回收和可循环稳定性的优势。
