Nikhil Govindarajan

Advisor: Prof. Meilin Liu (MSE) 

will propose a doctoral thesis entitled,

Development and Operando Characterization of Catalysts for Reversible Protonic Ceramic Electrochemical Cells

On

Thursday, November 20th  at 10:00 a.m.

Molecular Sciences and Engineering (MoSE) Room 3201A

Or

Virtually via Teams Link

Committee

            Prof. Meilin Liu - School of Materials Science and Engineering (Advisor)

            Prof. Hamid Garmestani - School of Materials Science and Engineering

            Prof. Preet Singh - School of Materials Science and Engineering

            Prof. Faisal Alamgir - School of Materials Science and Engineering

            Prof. David Flaherty - School of Chemical and Biomolecular Engineering

Abstract

Reversible proton conducting electrochemical cells (r-PCECs) have emerged as promising devices capable of converting electricity into useful chemical fuels via CO2 electrolysis, and vice versa via fuel oxidation. The commercialization of r-PCECs, however, is limited by the sluggish reaction kinetics and long-term durability of the air and fuel electrode materials

To address these issues, in the first study of this dissertation proposal, we will develop catalyst materials to improve performance by enhancing the ORR/OER kinetics in the air electrode. Electrochemical impedance spectroscopy (EIS) will be used to evaluate catalyst performance. A combination of Impedance analysis and operando Surface Enhanced Raman Spectroscopy (SERS) will be employed to elucidate the mechanistic details behind performance enhancement due to the catalyst. With that information, we will computationally search the material space to identify better catalysts and experimentally validate the screened catalysts to establish guidelines for the rational design of catalyst materials for air electrodes

In the second study, we will employ in-operando SERS to characterize the complex mass and charge transfer processes occurring at the cermet fuel electrodes during CO2 electrolysis. With specially designed model cells, we will utilize operando SERS to gain insight into how the degradation of fuel electrodes proceeds in CO2containing atmospheres. With this baseline established, we will perform a comparative operando SERS study of bare and catalyst-modified fuel electrodes to identify key features of the catalyst material that enhance the stability of fuel electrodes in CO2 containing atmospheres. This knowledge will enable the rational development of materials and catalysts for next generation r-PCECs for long-term, cost-effective energy storage and conversion.