Carl S, Will J, Madubuko N, Götz A, Przybilla T, Wu M, Raman N, Wirth J, Taccardi N, Zubiri B Apeleo, Haumann M, Wasserscheid P, Spiecker E
Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM), Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Cauerstraße 3, 91058 Erlangen, Germany.
Lehrstuhl für Chemische Reaktionstechnik (CRT), Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
J Phys Chem Lett. 2024 May 2;15(17):4711-4720. doi: 10.1021/acs.jpclett.3c03494. Epub 2024 Apr 24.
We present a comprehensive scale-bridging characterization approach for supported catalytically active liquid metal solutions (SCALMS) which combines lab-based X-ray microscopy, nano X-ray computed tomography (nano-CT), and correlative analytical transmission electron microscopy. SCALMS catalysts consist of low-melting alloy particles and have demonstrated high catalytic activity, selectivity, and long-term stability in propane dehydrogenation (PDH). We established an identical-location nano-CT workflow which allows us to reveal site-specific changes of Ga-Pt SCALMS before and after PDH. These observations are complemented by analytical transmission electron microscopy investigations providing information on the structure, chemical composition, and phase distribution of individual SCALMS particles. Key findings of this combined microscopic approach include (i) structural evolution of the SCALMS particles' GaO shell, (ii) Pt segregation toward the oxide shell leading to the formation of Ga-Pt intermetallic phases, and (iii) cracking of the oxide shell accompanied by the release of liquid Ga-Pt toward the porous support.
我们提出了一种用于负载型催化活性液态金属溶液（SCALMS）的全面的跨尺度表征方法，该方法结合了基于实验室的X射线显微镜、纳米X射线计算机断层扫描（nano-CT）和相关分析透射电子显微镜。SCALMS催化剂由低熔点合金颗粒组成，并已在丙烷脱氢（PDH）中表现出高催化活性、选择性和长期稳定性。我们建立了一个同位置纳米CT工作流程，这使我们能够揭示PDH前后Ga-Pt SCALMS的位点特异性变化。这些观察结果通过分析透射电子显微镜研究得到补充，该研究提供了有关单个SCALMS颗粒的结构、化学成分和相分布的信息。这种联合显微镜方法的关键发现包括：（i）SCALMS颗粒GaO壳的结构演变；（ii）Pt向氧化物壳的偏析导致形成Ga-Pt金属间相；（iii）氧化物壳的开裂伴随着液态Ga-Pt向多孔载体的释放。
