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Fe@SiO2 core-shell materials exhibit all the properties of model materials to be used as magnetic support and for investigation on CO and CO2 hydrogenation. The self-developed synthesis route for these iron-based core-shell particles makes it possible to tailor the model material properties. By selective variation of the synthesis parameters, the core size and shell thickness can thus be individually adjusted. The synthesis method via a bottom-up approach is suitable to fulfill this task. Standard material characterization supports the successful synthesis and reveals the different magnetic and catalytic properties. The possibility of using the magnetic properties in practice was demonstrated for application in wastewater treatment, with the core-shell particles acting as a magnetic support. Recovery and recycling of the particles was possible even by use of permanent magnets, which highlights the excellent separation performance from aqueous media. Testing of the accessibility of the core for synthesis gas is also successful and certifies the applicability as a solid catalyst. Moreover, the nanocomposite shows moderate activity in catalytic synthesis gas conversion such as CO and CO2 hydrogenation with high selectivity towards methanation or RWGS, respectively. Encapsulation of the active core results in significant stabilization, along with prevention of sintering and limitation of carbon deposition, as shown by post-reaction material characterization by TEM and TPH. Hence, these materials are excellent for studying structural changes of the active material, since deactivating effects, such as sintering or loss of active surface area by coke deposition, are excluded. Furthermore, the stoichiometric analysis of the experimental data with respect to the key components allowed, especially for CO hydrogenation, to support the conjectures of the structure-activity correlation. |
