Wang Songlin, Niu Hongying, Wang Jianji, Chen Tong, Wang Gongying, Zhang Jiamin
School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology Xinxiang 453003 P. R. China
Postdoctoral Programs, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University Xinxiang 453007 P. R. China
RSC Adv. 2019 Jul 1;9(35):20415-20423. doi: 10.1039/c9ra03931g. eCollection 2019 Jun 25.
Diphenyl carbonate (DPC) is a type of versatile industrial chemical, and the disproportionation of methyl phenyl carbonate (MPC) is a key step to produce DPC. However, the design and formulation of a catalyst for the efficient synthesis of DPC is a major challenge due to its small equilibrium constant. The support material is a critical factor influencing the performance of Pb nanocatalysts. Thus, a series of Pb-based catalysts over MgO, ZrO, SiO, TiO and AlO were prepared to investigate the effect of the support materials on the physicochemical properties and catalytic performances for the conversion of MPC to effectively synthesize DPC. The catalysts were well characterized by XRD, BET, TEM, XPS, ICP-OES, H-TPR, Py-IR and NH-TPD. The results showed that the nature of the support obviously affected the structural properties and catalytic performances, and Pb was dispersed better on SiO, TiO, ZrO and MgO than on AlO, and showed stronger metal-support interaction over MgO and ZrO. The activity results revealed that PbO/MgO and PbO/ZrO exhibited higher catalytic activities because they contained higher Pb dispersion and more Lewis acid sites, and the catalytic activities followed the order PbO/MgO > PbO/ZrO > PbO/SiO > PbO/AlO > PbO/TiO. On the contrary, PbO/MgO and PbO/ZrO exhibited better reusability due to strong interaction between the highly dispersed Pb and the supports, and the activity decrease in the case of PbO/SiO, PbO/AlO and PbO/TiO mainly resulted from the Pb leaching loss. This work would contribute to exploiting novel catalytic materials in a wide range of applications for the efficient synthesis of organic carbonates.
碳酸二苯酯（DPC）是一种用途广泛的工业化学品，碳酸苯甲酯（MPC）的歧化反应是生产DPC的关键步骤。然而，由于其平衡常数较小，设计和制备用于高效合成DPC的催化剂是一项重大挑战。载体材料是影响Pb纳米催化剂性能的关键因素。因此，制备了一系列负载在MgO、ZrO、SiO、TiO和AlO上的Pb基催化剂，以研究载体材料对MPC转化为DPC的物理化学性质和催化性能的影响。通过XRD、BET、TEM、XPS、ICP-OES、H-TPR、Py-IR和NH-TPD对催化剂进行了充分表征。结果表明，载体的性质明显影响结构性能和催化性能，Pb在SiO、TiO、ZrO和MgO上的分散性优于在AlO上，并且在MgO和ZrO上表现出更强的金属-载体相互作用。活性结果表明，PbO/MgO和PbO/ZrO表现出较高的催化活性，因为它们具有较高的Pb分散度和更多的Lewis酸位点，催化活性顺序为PbO/MgO > PbO/ZrO > PbO/SiO > PbO/AlO > PbO/TiO。相反，PbO/MgO和PbO/ZrO由于高度分散的Pb与载体之间的强相互作用而表现出更好的可重复使用性，而PbO/SiO、PbO/AlO和PbO/TiO活性的降低主要是由于Pb的浸出损失。这项工作将有助于开发新型催化材料，广泛应用于有机碳酸酯的高效合成。
