Enamine Ltd., Chervonotkatska Street 78, 02094 Kyiv, Ukraine.
L.V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Prosp. Nauky 31, 03028 Kyiv, Ukraine.
Molecules. 2023 Jan 26;28(3):1201. doi: 10.3390/molecules28031201.
A series of seven palladium-containing composites, i.e., four Pd/C and three Pd(OH)/C (Pearlman's catalysts), was prepared using modified common approaches to deposition of Pd or hydrated PdO on charcoal. All the composites were tested in the catalytic hydrogenation of diene carboxylates with the isolated-ring scaffold, e.g., 5,6-dihydropyridine-1(2)-carboxylates with 2-(alkoxycarbonyl)cyclopent-1-en-1-yl and hex-1-en-1-yl substituents at the C(4)-position. The performance of the composites was also studied via the hydrogenation of quinoline as a model reaction. The composites were characterized by transmission and scanning electron microscopy (TEM and SEM), powder X-ray diffraction, and low-temperature N adsorption. It was found that the composites containing Pd nanoparticles (NPs) of 5-40 nm size were the most efficient catalysts for the hydrogenation of dienes, providing the reduced products with up to 90% yields at p(H) = 100 atm, T = 30 °C for 24 h. The method of Pd NPs formation had more effect on the catalyst performance than the size of the NPs. The catalytic performance of Pearlman's catalysts (Pd(OH)/C) in the hydrogenation of dienes was comparable to or lower than the performance of the Pd/C systems, though the Pearlman's catalysts were more efficient in the hydrogenation of quinoline.
采用改良的常用方法，制备了一系列七种含钯复合材料，即四种 Pd/C 和三种 Pd(OH)/C（Pearlman 催化剂）。所有复合材料均在催化氢化具有孤立环支架的二烯羧酸酯中进行了测试，例如，在 C(4)-位具有 2-(烷氧基羰基)环戊-1-烯-1-基和己-1-烯-1-基取代基的 5,6-二氢吡啶-1(2)-羧酸酯。还通过氢化喹啉作为模型反应研究了复合材料的性能。通过透射电子显微镜 (TEM) 和扫描电子显微镜 (SEM)、粉末 X 射线衍射和低温 N 吸附对复合材料进行了表征。发现含有 5-40nm 尺寸的钯纳米颗粒 (NPs) 的复合材料是二烯氢化最有效的催化剂，在 p(H) = 100atm、T = 30°C 下反应 24 小时，可提供高达 90%收率的还原产物。Pd NPs 形成方法对催化剂性能的影响大于 NPs 尺寸的影响。尽管 Pearlman 催化剂（Pd(OH)/C）在氢化喹啉中的效率更高，但在二烯的氢化中，其催化性能与 Pd/C 体系相当或更低。
