In the etzoldlab
In the etzoldlab the challenges arising with the needed global energy change and future sustainable feedstock supply for chemical industry are the major research guideline. From the perspective of applied chemistry, a multidisciplinary approach is employed to provide scientific solutions for these challenges, especially for the complex interplay of catalytic materials within a full process or device. In the scientific approach, generic experiments play a dominant role. They allow controlling process conditions from highly idealized towards technically realistic and are combined with diagnostics providing in-situ information. Chemical reaction engineering simulations complement the experiments, giving especially insights into complex mass transfer phenomena and, therefore making a more holistic picture possible. As a future sustainable energy and chemical industry will need a concerted interaction of electrochemical and classical heterogeneous catalyzed processes both are studied. Based on this strategy, the research of the etzoldlab can be divided in three strongly interacting sub-groups: Advanced Catalytic Materials – Electrochemical Energy Conversion Processes – Heterogeneous Catalysis and Processes. More details on the research of these subgroups can be found in the sections below.
With our research we are part of the following huger or collaborative research activities:
In electrochemical energy conversion processes the complex interplay of activity/selectivity and mass transfer of catalytic materials and carbonaceous electrodes in multiphase (gas/liquid) systems is studied. Processes are the polymer electrolyte fuel cell and electrolysis as also the CO2 reduction. In this sense catalysts for the ORR, HER, OER and CO2RR are studied. For boosting activity, selectivity and stability in these reactions an innovative approach, complementary to tuning nanoparticle properties, is employed. In this approach tiny amounts of Ionic Liquid (IL) are employed to modify the active site microenvironment. This SCILL approach (Solid Catalyst with Ionic Liquid Layer) was pioneered by us for heterogeneous catalysis in 2007 and is studied intensively, to leverage its full potential in electrocatalysis. As classical rotating disc electrode (RDE) studies are strongly limited in the achievable current density and cannot reach potentials where technical systems operate and furthermore show no true triple-phase-boundary, further efforts are needed to study catalysts under technical relevant conditions. For this purpose, in the etzoldlab on the one hand half cells based on gas-diffusion-electrodes are employed, which allows to study a triple-phase-boundary on a single half cell side without interference from either the counter reaction or polymer electrolyte membrane. On the other hand full membrane electrode assembly (MEA) testing is carried out on fuel cell testing stations. Important cornerstone for both techniques is the highly accurate and reproducible deposition of catalyst layers, which is carried out by robot assisted ultrasound spraying.
- G.-R. Zhang, T. Wolker, D.J.S. Sandbeck, M. Munoz, K.J.J. Mayrhofer, S.Cherevko and B.J.M. Etzold, “Tuning the Electrocatalytic Performance of Ionic Liquid Modified Pt Catalysts for Oxygen Reduction Reaction via Cationic Chain Engineering”. ACS Catal. 90, (2018) 8244.
- I. Martinaiou, T. Wolker, A. Shahraeia, G.-R. Zhang, A. Janßen, S. Wagner, N. Weidler, R.W. Stark, B.J.M. Etzold and U.I. Kramm, “Improved electrochemical performance of Fe-N-C catalysts through ionic liquid modification in alkaline media”.J. Power Sources 375, (2018) 222.
- T. Ariyanto, A. Kern, B.J.M. Etzold and G.-R. Zhang, “ Carbide-derived carbon with hollow core structure and its performance as catalyst support for methanol electro-oxidation”. Electrochem. Commun. 82, (2017) 12.
- G.-R. Zhang, and B.J.M. Etzold, “Ionic liquids in electrocatalysis”. J. Energ. Chem. 25, (2016) 199.
- G.-R. Zhang, M. Munoz, and B.J.M. Etzold, “Accelerating Oxygen Reduction Catalysts through Preventing Poisoning with Non-Reactive Species by Using Hydrophobic Ionic Liquids”. Angew. Chem. Int. Ed. 55, (2016) 2257.
A) Boosting effect of imidazolium based cations with different alkyl chain length and [NTf2] as anions for platinum catalyst in ORR@0.9V; B) Schematic of half cell based on a gas-diffusion-electrode for achieving high current densities and technical relevant potentials.