PhD Defense in Chemistry
- Thursday, January 13, 2022 at 9:30am
- Chemistry & Biochemistry Bldg, Byker Auditorium - view map
Mr. Elias Pomeroy will defend his PhD in Chemistry beginning with a seminar titled “Operando Optical and Quantitative Electrochemical Studies of Solid Oxide Fuel Cell Anode Degradation and Regeneration.”
Abstract: Solid Oxide Fuel Cells (SOFCs) are high temperature (600-1000 °C) devices which can generate electricity from a wide variety of fuels at extremely high efficiencies. Unfortunately, SOFC anodes are susceptible to gas phase contaminants, especially sulfur, and graphitic carbon formation. Additionally, the extreme operating conditions of SOFCs make studying their chemistries challenging. This presentation will explore new quantitative electrochemical methodologies and operando optical to study degradation and remediation of SOFC anodes. First, since typical electrochemical techniques infer microstructural changes rather than directly measuring surface area, a traditional electrochemical technique, chronocoulometry (CC), was adapted to SOFCs for the first time to measure the electrochemically active area of the anode. This technique showed that active area is temperature dependent, that sulfur poisons SOFC anodes in a more complex manner than simply blocking active sites, and carbon monoxide decreased the number of active sites. Next, operando thermal imaging, in combination with mass spectrometry, Fourier transformed infrared emission spectroscopy, and electrochemistry explored different methodologies of carbon remediation, comparing electrochemical oxidation, molecular oxygen, and steam as methods to remove graphite accumulated on SOFC anodes. This study found that with all methods, CO2 played a key role in removing carbon, that both electrochemical oxidation and steam removed carbon more globally than oxygen, and that imaging the entire cell is key to understanding the complex chemistry occurring on SOFCs.
Advisor: Prof. Rob Walker
Byker Auditorium (masks must be worn) or WEBEX
- Department of Chemistry and Biochemistry