Bastian Rutjens


Tin oxide nanoparticles for CO2-reduction towards formate in aqueous electrolytes

Schematic illustration for the setup of CO2- electrolysis towards formate. Copyright: B.Rutjens Schematic illustration for the setup of CO2- electrolysis towards formate.

Climate change is currently one of the most discussed topics in Germany. Greenhouse gases such as carbon dioxide (CO2) are increasing the temperatures worldwide. This has serious consequences for the Earth, including extreme weather events. Therefore, the reduction of carbon dioxide emissions is an important goal for the Federal Republic of Germany. In this context, researchers and industry are interested in using CO2 exhaust gases as feedstock to produce value-added chemicals. One consideration is to convert CO2 by electrochemical reduction into base chemicals such as formic acid, carbon monoxide or ethanol, which can be used directly in industry to save fossil-based chemicals [1].

In CO2 electrolysis, the catalyst plays an important role and has an influence on the resulting product. Lead (Pb), mercury (Hg), indium (In) and tin (Sn) are particularly suitable for the selective production of formate in aqueous electrolyte. Likewise, tin oxide nanoparticles (SnO2) show a high selectivity towards formate. SnO2 nanoparticles and their syntheses offer various possibilities for the optimization of the CO2 electrolysis [2, 3].

The aim of this master thesis is the analysis and optimization of SnO2 nanoparticles produced by different synthesis routes, e.g. solvothermal synthesis, and the investigation with respect to the reduction of CO2 towards formate. For the electrochemical analysis the Rotating Disc Electrode (RDE) method will be used (see figure). This method is suitable as a tool for rapid catalyst screening. Furthermore, analytical methods such as ion chromatography (IC), scanning electron microscopy (SEM) and laser scanning microscopy (LSM) are used to study the ongoing reaction processes.

[1] J. M. Spurgeon, B. Kumar, Energy and Environmental Science 2018, 11, 1536–1551.
[2] D. Mohanta, M. Ahmaruzzaman, RSC Advances 2016, 6, 110996–111015.
[3] S. Zhang, P. Kang, T. J. Meyer, Journal of the American Chemical Society 2014, 136, 1734-1737.