(2f) Tracking the Dynamics of Metal Nanomaterial to Improve Catalyst Design for Sustainable Fuel Production

The challenges posed by climate change have increased global interest in sustainable fuel production. Technologies like water electrolyzers and hydrogen fuel cells offer unique opportunities for generating sustainable energy. However, the slow kinetics of the oxygen reactions in these systems necessitate the optimization of catalyst materials. Currently, expensive precious metals such as platinum (Pt) and Iridium (Ir) are commonly employed as catalysts for the oxygen evolution and oxygen reduction reaction, respectively. To promote the widespread adoption of these technologies and reduce costs, two strategies can be pursued to develop novel and improved catalysts: A) enhancing the utility and durability of the precious metal, or B) replacing precious metals with non-Pt-group metals. To effectively implement these strategies and generate improved catalysts, a comprehensive understanding of the dynamic nature of catalyst materials during electrocatalytic conditions is crucial. Therefore, I am interested in tracking various factors such as catalyst redox behavior, surface reconstruction, and catalyst degradation to gain insights into the dynamics of the catalysts under operation. These insights are invaluable for optimizing catalysts and advancing the cost-effective production of sustainable fuels.

Doctoral Research:

During my time as a PhD student at the University of Bremen (Germany) and the University of Bern (Switzerland), my research covered a wide range of areas, from synthesis to performance evaluation under realistic reaction conditions of Pt and Ir electrocatalysts for hydrogen fuel cells and water electrolyzers, following strategy A). As part of my work, I have developed innovative electrochemical cells, specifically gas diffusion electrode setups. These setups enable high throughput screening of electrocatalysts as reached by conventional rotating disk electrode setups, while also allowing the study of catalyst behavior in a device-like environment, eliminating the need to construct an entire application device. Using these gas diffusion electrode setups, I have conducted degradation studies on Pt catalysts for oxygen reduction, as well as performance testing of Ir catalysts for oxygen evolution, both under realistic reaction conditions. Additionally, I have performed various in-situ degradation studies to monitor changes in Pt nanoparticle size via small-angle X-ray scattering with a focus on distinguishing between electrochemical and classical Ostwald ripening as degradation mechanism.

Postdoctoral Research:

As a Postdoctoral Researcher at Stanford University and SLAC National Accelerator Laboratory, my research focuses on the development and investigation of low or non-precious metal nanomaterials for water electrolyzers and hydrogen fuel cells. Following strategy B), my work encompasses two key aspects: (1) Investigating multi-metal Fe-based catalysts for the oxygen evolution reaction: To gain insights into the catalyst performance and dynamics techniques such as inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy are employed to identify metal dissolution and oxidation state changes, respectively. This aspect of my work is currently in progress. (2) Tracking dynamic oxidation state changes of a Ag/MnO_x thin film oxygen reduction catalyst using in-situ/operando X-ray absorption spectroscopy: This research has already been published and provides valuable insights into the behavior of the catalyst depending on the applied potential, microenvironment, and occurrence of catalysis. All my research is driven by the motivation to gain a comprehensive understanding of catalyst dynamics under operational conditions, with the ultimate goal of developing improved catalyst materials.

Teaching Interests:

I believe that teaching and mentoring are essential responsibilities within the academic system. Since the early stage of my bachelor studies, I have been actively involved in academic teaching. Nowadays, mentoring early-career scientists has become an integral part of my daily work. Along this journey, I have had the privilege of encountering remarkable role models, exceptional mentors who not only possess a deep passion for imparting knowledge but also demonstrate extraordinary empathy and enthusiasm in supporting and witnessing the growth of their mentees. Their profound influence has left an indelible mark on me, serving as a constant inspiration to continuously enhance my skills and become a more effective mentor each day.