Dietrich Christine, Chen Si, Uzunidis Georgios, Hähsler Martin, Träutlein Yannick, Behrens Silke
Institute of Catalysis Research and Technology (IKFT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1 D, 76344, Eggenstein-Leopoldshafen, Germany.
Institute of Inorganic Chemistry, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
ChemistryOpen. 2021 Feb;10(2):296-304. doi: 10.1002/open.202000298.
Multimetallic nanoparticles often enhance the catalytic performance of their monometallic counterparts by increasing reaction rates, catalyst selectivity, and/or stability. A prerequisite for understanding structure- and composition-associated properties, however, is the careful design of multimetallic nanoparticles with various structures and compositions. Here, bimetallic Pd/Sn-based nanoparticles are prepared with a tunable composition and structure exploiting ionic liquids (ILs) as reaction medium (i. e., methyltrioctylammonium bis(trifluoromethylsulfonyl)imide). The nanoparticles are obtained in a one-pot synthetic procedure by reducing the metal salt precursors with triethylborohydride in the IL. The results show that the reaction parameters, in particular the nature and ratio of the Pd /Sn precursors as well as the reaction temperature, influence NP formation and composition. X-ray diffraction with Rietveld analysis and transmission electron microscopy are employed to determine NP size and phase composition. Under optimized reaction conditions Pd Sn or PdSn nanocrystals are formed as single-phase products after introducing an additional annealing step at 200 °C. Nanocrystals with intermetallic composition reveal enhanced catalytic properties in the semihydrogenation of diphenylacetylene which was used as a model reaction.
多金属纳米粒子通常通过提高反应速率、催化剂选择性和/或稳定性来增强其单金属对应物的催化性能。然而，理解与结构和组成相关的性质的一个先决条件是精心设计具有各种结构和组成的多金属纳米粒子。在此，利用离子液体（ILs）作为反应介质（即甲基三辛基铵双（三氟甲基磺酰基）亚胺）制备了具有可调组成和结构的双金属Pd/Sn基纳米粒子。通过在IL中用三乙基硼氢化钠还原金属盐前驱体，在一锅合成过程中获得纳米粒子。结果表明，反应参数，特别是Pd/Sn前驱体的性质和比例以及反应温度，会影响纳米粒子的形成和组成。采用Rietveld分析的X射线衍射和透射电子显微镜来确定纳米粒子的尺寸和相组成。在优化的反应条件下，在200°C引入额外的退火步骤后，形成了PdSn或PdSn纳米晶体作为单相产物。具有金属间化合物组成的纳米晶体在用作模型反应的二苯乙炔半加氢反应中显示出增强的催化性能。
