Inside the Laboratory is a joint series with LCGC International and Spectroscopy, profiling analytical scientists and their research groups at universities all over the world. This series spotlights the current chromatographic and spectroscopic research their groups are conducting, and the importance of their research in analytical chemistry and specific industries. In this edition of “Inside the Laboratory,” Dr. Bryan Eigenbrodt of Villanova University, in Villanova, Pennsylvania, discusses his laboratory’s work using operando spectroscopic techniques to better understand the chemistry occurring in alternative energy fuel cell devices such as solid oxide fuel cells (SOFCs). Note that operando spectroscopic techniques are used to study chemical reactions under realistic operating conditions.
Dr. Bryan Eigenbrodt is the lead investigator of the Eigenbrodt Research Laboratory. He has served as a professor in the chemistry department at Villanova University since August 2013. His research group focuses on two projects: the first project involves students investigating the chemistry occurring in solid oxide fuel cells (SOFCs) at temperatures as high as 800 °C. The second project explores effective means for generating biofuels from different microalgae specimens.
Recently, Spectroscopy sat down with Dr. Eigenbrodt about the ongoing research in his laboratory.
Can you talk about the analytical or spectroscopic techniques that your group used in your most recent research project?
The main research focus in my laboratory revolves around exploring the fundamental chemistry occurring in alternative energy fuel cell devices. My research relies heavily on utilizing advanced spectroscopic techniques for their investigations to provide Villanova University students a “creation to application” experience in these prevalent alternative energy fields.
There are many different types of fuel cell systems, but the area of interest for my group is in SOFCs. SOFCs are scalable solid-state electrochemical devices that can directly convert chemical energy stored in various fuels to electrical energy with conversion efficiencies as high as 80–90%. This is leaps and bounds over the fuel conversion of standard combustion engines that can range from 15–45%. Although SOFC technology has been targeted for small and large-scaled stationary power generation, the high energy densities of SOFCs (compared to batteries) and recent material advancements have provided potential opportunities for applications in portable devices and transportation.
A couple of standout technical hurdles have been delaying the progress of SOFC technology to take the next step as a reliable alternative energy source and have therefore also become a driving force in the research efforts of this field. The first hurdle is the lack of knowledge in electrode catalysts material chemistry and fuel chemistry during SOFC actual device operation. This is brought upon by extreme operating conditions that creates a challenge to conduct operando spectroscopic measurements. The second obstacle, which is really a new direction for SOFCs, is the deviation away from its standard hydrogen fuel source to a hydrocarbon one. This deviation is motivated mainly by challenges associated with the storage of this combustible fuel and the large generation expense. In my research group, students synthesize new electrode catalysts that have the potential of operating in these harsh hydrocarbon fuel environments.
Because of experimental challenges brought upon by fuel cell operating conditions (temperatures of 800 °C) and inaccessible device architectures, researchers are typically limited to electroanalytical measurements such as voltammetry and impedance type measurements. These techniques can provide information about the resistive elements and electrochemical efficiencies of the SOFC devices. Although these methods provide valuable information about changes in performance and operating conditions, these electrochemical techniques are intrinsically nonspecific and cannot provide detailed information about the structural and chemical changes that are leading to these observed changes in electrochemical performance.
In my research laboratory, we are coupling advanced operando spectroscopic techniques with electrochemical measurements to provide an unparalleled understanding of how these fuel cell materials and different fuels behave during SOFC device operation. The unprecedented information gained can also help guide the development of efficient SOFC assemblies for future power generation. Specifically, we have created operando SOFC systems that have been used with Raman spectroscopy and utilized at the Advanced Photon Source at Argonne National Laboratory to take advantage of their X-ray absorption spectroscopy (XAS) capability. Both instruments can explore different aspects of SOFCs. The Raman spectroscopy experiments that we employ can explore catalyst stability and fuel breakdown chemistry during device operation. The use of XAS allows us to explore the changes in oxidation state of our perovskite catalyst to understand which metals play a role in electronic and ionic conduction processes. In addition, XAS also allows us to explore the crystal structure of our material and how it can be affected during operational conditions.
Can you explain the importance of your research within the broader field
of analytical chemistry or spectroscopy, or in a specific industry/application?
Although electrochemical methods can explore the performance of the SOFC as a function of fuel exposure, these techniques cannot identify with material or molecular specificity of the species present. Optical spectroscopy, vibrational in particular, is uniquely well suited for operando observation of specific molecular and material species. Unlike traditional standalone electrochemical measurements or ex situ analyses, the optical method used in this work provides real time, materials-specific in situ information about the chemistry occurring in operating SOFCs. Such data provide the quantitative benchmarks needed to test proposed models of electrochemical fuel oxidation in these devices. More importantly, being able to differentiate mechanisms of SOFC operation as a function of fuel identity and cell polarization can help guide the development of new, more effective SOFC materials and architectures. Specifically, these operando measurements can provide an unparalleled understanding of how these fuel cell materials and different fuels behave during SOFC device operation. The unprecedented information gained can also help guide the development of efficient SOFC assemblies for future power generation. With access to this operando chamber and the Raman spectrometer, undergraduate and graduate students will be able to witness and investigate fuel cell chemistry in these extreme alternative energy environments that very few researchers in this field have had the privilege to observe.
How do you stay updated with advancements in analytical chemistry and spectroscopic techniques and technologies?
To stay updated with advancements with analytical chemistry and spectroscopic techniques in my field, I make sure that I stay up to date on the literature. The SOFC field that I am in is dominated by electroanalytical techniques because of the experimental challenges brought upon by the high operational temperatures (~800 oC) of these electrochemical devices. Even if you could open these devices while they are operating, your spectroscopic instrument would be bombarded with a significant amount of blackbody and visible radiation that would saturate most detectors. Because we are utilizing a couple of spectroscopic techniques that can handle these operational challenges, Raman and X-ray absorption spectroscopy, this provides us with a unique opportunity. When we are searching through the literature, we can now ask ourselves, “can we provide a different perspective on this published research by providing an operando spectroscopic perspective?” Another way we stay updated with spectroscopic advancements is to have an “open mind” about instruments and their capabilities. An instrument company might create certain sample holders or instrument configurations that can serve most of the scientific population and allow them to become profitable. But if you have an “open mind” you can create unique ways to test specific chemical environments by designing new sample holders or new instrumental configurations that fit your scientific needs. A good place to start with this is to talk with the technical support of that company or delve into literature and see if other researchers have similar mind sets and have already designed similar systems.
Can you discuss a recent innovation or development that you find particularly impactful or exciting?
In the field of alternative energy, the predominate technique for analyzing systems is through electroanalytical techniques. Studying voltage, current and impedance as a function of operational conditions can provide valuable information but can lack the chemical and material specific knowledge that can push these technologies into the future. What has been on the rise in this field as well as many other fields is the merger of electroanalytical techniques with concurrent spectroscopic techniques or what some people will call “spec-echem.” No matter what field it might be, the use of spec-echem can provide a “full picture” of a chemical system and its applications.