Shao Dongyun, Li Youxin
Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University Room C412-8, Building 24, 92 Weijin Road, Nankai District Tianjin 300072 China
RSC Adv. 2018 Jun 5;8(36):20379-20393. doi: 10.1039/c8ra01828f. eCollection 2018 May 30.
A series of novel immobilized platinum catalysts was prepared by loading Pt onto silica particles modified with polycarboxylic acid groups such as diethylenetriaminepentaacetic acid (DTPA), nitrolotriacetic acid (NTA) and succinic acid (SA). The three modified heterogeneous Pt catalysts were characterized using infrared spectroscopy (IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and atomic absorption spectroscopy (AAS). The residual HPtCl solutions were characterized using ultraviolet spectroscopy (UV). The polycarboxylic acid-functionalized silica supported Pt catalysts were used to catalyze alkene hydrosilylation and 1-hexene was chosen as a model alkene. The data indicated that the catalytic performance was strongly dependent on the properties of the polycarboxylic acid group bonded to the silica particles. Among them, DTPA-functionalized silica supported Pt (SiO-DTPA-Pt) showed the best catalytic activity and reusability. Furthermore, some hydrosilylation reactions between other linear alkenes (1-heptene, 1-octene, 1-decene, 1-do-decene, 1-tetra-decene, 1-hexa-decene, 1-octa-decene, styrene or -hex-2-ene), or ring type alkenes (norbornene) with methyldichlorosilane could be catalyzed in the presence of these three Pt catalysts. Their high activities were more than 90%, and their selectivities were more than 99%, which were apparently better than homogeneous Pt catalysts. In addition, reactions with cyclohexene were also successfully catalyzed by the Pt catalysts. These results indicate that the polycarboxylic acid-functionalized silica gel supported Pt catalysts have potential value in industrial hydrosilylation reactions.
通过将铂负载到用二亚乙基三胺五乙酸（DTPA）、次氮基三乙酸（NTA）和琥珀酸（SA）等多元羧酸基团改性的二氧化硅颗粒上，制备了一系列新型固定化铂催化剂。使用红外光谱（IR）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）、能量色散X射线光谱（EDS）和原子吸收光谱（AAS）对这三种改性多相铂催化剂进行了表征。使用紫外光谱（UV）对残留的HPtCl溶液进行了表征。将多元羧酸官能化的二氧化硅负载铂催化剂用于催化烯烃硅氢化反应，并选择1-己烯作为模型烯烃。数据表明，催化性能强烈依赖于键合到二氧化硅颗粒上的多元羧酸基团的性质。其中，DTPA官能化的二氧化硅负载铂（SiO-DTPA-Pt）表现出最佳的催化活性和可重复使用性。此外，在这三种铂催化剂存在下，可以催化其他线性烯烃（1-庚烯、1-辛烯、1-癸烯、1-十二碳烯、1-十四碳烯、1-十六碳烯、1-十八碳烯、苯乙烯或2-己烯）或环型烯烃（降冰片烯）与甲基二氯硅烷之间的一些硅氢化反应。它们的高活性超过90%，选择性超过99%，明显优于均相铂催化剂。此外，铂催化剂也成功催化了与环己烯的反应。这些结果表明，多元羧酸官能化的硅胶负载铂催化剂在工业硅氢化反应中具有潜在价值。
