Talgatov Eldar T, Naizabayev Akzhol A, Bukharbayeva Farida U, Kenzheyeva Alima M, Yersaiyn Raiymbek, Auyezkhanova Assemgul S, Akhmetova Sandugash N, Zhizhin Evgeniy V, Brodskiy Alexandr R
D.V. Sokolskiy Institute of Fuel, Catalysis and Electrochemistry, Almaty 050010, Kazakhstan.
Department of Physics and Technology, Al Farabi Kazakh National University, Almaty 050040, Kazakhstan.
Nanomaterials (Basel). 2024 Aug 26;14(17):1392. doi: 10.3390/nano14171392.
Recently, Pd catalysts supported on magnetic nanoparticles (MNPs) have attracted a great attention due to their ability of easy separation with an external magnet. Modification of MNPs is successfully used to obtain Pd magnetic catalysts with enhanced catalytic activity. In this work, we discussed the effect of titania content in TiO/MNPs support materials on catalytic properties of Pd@TiO/MNPs catalysts in phenylacetylene hydrogenation. TiO/MNPs composites were prepared by simple ultrasound-assisted mixing of TiO and MNPs, synthesized by co-precipitation method. This was followed by deposition of palladium ions on the mixed metal oxides using NaOH as precipitant. The supports and catalysts were characterized using XRD, BET, STEM, EDX, XPS, and a SQUID magnetometer. Pd nanoparticles (5-6 nm) formed were found to be homogeneously distributed on support materials representing the well-mixed metal oxides with TiO content of 10, 30, 50, or 70%wt. Testing of the catalysts in phenylacetylene hydrogenation showed that their activity increased with increasing TiO content, and the process was faster in alkali medium (pH = 10). The hydrogenation rates of triple and double C-C bonds on Pd@70TiO/MNPs achieved 9.3 × 10 mol/s and 23.1 × 10 mol/s, respectively, and selectivity to styrene was 96%. The catalyst can be easily recovered with an external magnet and reused for 12 runs without significant degradation in the catalytic activity. The improved catalytic properties of Pd@70TiO/MNPs can be explained by the fact that the surface of the support is mainly composed of TiO particles, affecting the state and size of Pd species.
最近，负载在磁性纳米颗粒（MNPs）上的钯催化剂因其能够通过外部磁铁轻松分离而备受关注。对MNPs进行改性已成功用于获得具有增强催化活性的钯磁性催化剂。在这项工作中，我们讨论了TiO/MNPs载体材料中二氧化钛含量对Pd@TiO/MNPs催化剂在苯乙炔加氢反应中催化性能的影响。通过简单的超声辅助混合TiO和通过共沉淀法合成的MNPs制备了TiO/MNPs复合材料。随后使用NaOH作为沉淀剂将钯离子沉积在混合金属氧化物上。使用XRD、BET、STEM、EDX、XPS和超导量子干涉仪对载体和催化剂进行了表征。发现形成的钯纳米颗粒（5-6纳米）均匀分布在载体材料上，这些载体材料代表了TiO含量为10%、30%、50%或70%wt的充分混合的金属氧化物。在苯乙炔加氢反应中对催化剂进行测试表明，它们的活性随着TiO含量的增加而提高，并且在碱性介质（pH = 10）中反应更快。Pd@70TiO/MNPs上三键和双键C-C的加氢速率分别达到9.3×10⁻³mol/s和23.1×10⁻³mol/s，对苯乙烯的选择性为96%。该催化剂可以通过外部磁铁轻松回收，并重复使用12次，催化活性没有明显下降。Pd@70TiO/MNPs催化性能的提高可以通过载体表面主要由TiO颗粒组成这一事实来解释，这影响了钯物种的状态和尺寸。
