Wolf Moritz, Raman Narayanan, Taccardi Nicola, Horn Raimund, Haumann Marco, Wasserscheid Peter
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Lehrstuhl für Chemische Reaktionstechnik (CRT), Egerlandstr. 3, 91058 Erlangen, Germany.
Technische Universität Hamburg (TUHH), Institut für Chemische Reaktionstechnik, V-2, Eißendorfer Str. 38, 21073 Hamburg, Germany.
Faraday Discuss. 2021 May 1;229:359-377. doi: 10.1039/d0fd00010h. Epub 2021 Mar 5.
Supported liquid phase catalysis has great potential to unify the advantages from both homogeneous and heterogeneous catalysis. Recently, we reported supported catalytically active liquid metal solutions (SCALMS) as a new class of liquid phase catalysts. SCALMS enable high temperature application due to the high thermal stability of liquid metals when compared to supported molten salts or ionic liquids. The highly dynamic liquid metal/gas interface of SCALMS allows for catalysis over single atoms of an active metal atom within a matrix of liquid gallium. In the present study, kinetic data is acquired along the catalyst bed in a compact profile reactor during propane dehydrogenation (PDH) over gallium-platinum SCALMS. The reactor design allows for the analysis of the temperature and gas phase composition along the catalyst bed with a high spatial resolution using a sampling capillary inside the reactor. The concentration profiles suggest enhanced deactivation of the catalyst at the end of the bed with a deactivation front moving from the end to the beginning of the catalyst bed over time on stream. Only minor amounts of side products, formed via cracking of propane, were identified, supporting previously reported high selectivity of SCALMS during alkane dehydrogenation. The acquired data is supported by in situ high-resolution thermogravimetry coupled with mass spectrometry to monitor the activity and coking behaviour of SCALMS during PDH. The results strongly suggest an enhanced formation of coke over AlO-supported SCALMS when compared to using SiO as the support material.
负载型液相催化具有整合均相催化和多相催化优势的巨大潜力。最近，我们报道了负载型催化活性液态金属溶液（SCALMS）作为一类新型的液相催化剂。与负载型熔盐或离子液体相比，由于液态金属具有高热稳定性，SCALMS能够在高温下应用。SCALMS高度动态的液态金属/气体界面允许在液态镓基质中的活性金属原子的单个原子上进行催化。在本研究中，在紧凑型反应器的催化剂床层上，以镓-铂SCALMS进行丙烷脱氢（PDH）过程中，沿催化剂床层获取动力学数据。该反应器设计允许使用反应器内部的采样毛细管以高空间分辨率分析沿催化剂床层的温度和气相组成。浓度分布表明，随着反应时间的延长，催化剂床层末端的失活增强，失活前沿从催化剂床层末端向起始端移动。仅鉴定出少量通过丙烷裂解形成的副产物，这支持了先前报道的SCALMS在烷烃脱氢过程中的高选择性。所获取的数据得到原位高分辨率热重分析与质谱联用的支持，以监测PDH过程中SCALMS的活性和结焦行为。结果强烈表明，与使用SiO作为载体材料相比，AlO负载的SCALMS上焦炭的形成有所增加。
