Developing electrochemical methodologies towards addressing challenges in flow energy conversion technologies

Electrolyzer technologies for sustainable fuel production face critical catalyst optimization challenges, particularly in developing energy-efficient alternatives to the oxygen evolution reaction that dominates electrolyzer energy consumption. This dissertation presents electrochemical methodologies developed to systematically address catalyst discovery and optimization for glycerol electrooxidation as a promising anodic reaction that can significantly reduce electrolyzer energy requirements while producing valuable chemicals from biomass waste. Beginning with fundamental interfacial characterization, an SECM-based spot analysis methodology was established that quantifies heterogeneous electron transfer kinetics and identifies deviations from ideal electrochemical behavior at carbon electrode interfaces. Building on these diagnostic capabilities, a modified flooded microwell SECCM approach was developed that overcame meniscus instability issues in alkaline media to enable screening of bimetallic catalyst arrays, demonstrating superior performance of Au-Pd systems over other bimetallic combinations for glycerol electrooxidation. However, the inherent limitations of scanning probe techniques—particularly restricted scalability, limited automation potential, and low experimental throughput—necessitated the development of more versatile screening architectures. To address these fundamental bottlenecks, an individually addressable electrode array methodology was implemented, which integrated with semi–automated synthesis and characterization protocols, enabled the successful screening of unique Au electrodeposition conditions and the identification of optimal parameters that correlate specific surface facets with electrocatalytic performance. This automated platform was extended to systematically evaluate 77 Au-Pd bimetallic compositions, revealing that ~45% Pd loading represents the optimal catalyst formulation that combines high activity, favorable kinetics, and great stability across multiple performance metrics. Validation through scaled-up flow electrolyzer experiments confirmed enhanced C-C bond cleavage activity and stable long-term operation, demonstrating successful translation from microscale screening to practical electrochemical systems. By systematically addressing the methodological bottlenecks that have constrained electrocatalyst discovery, this work provides scalable approaches for rational catalyst design that enable efficient biomass valorization in electrolyzer systems, contributing essential capabilities for sustainable chemical production and industrial decarbonization.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Gaddam, Raghuram

Contributors dc:contributor

• Rodríguez-López, Joaquín
• Shoemaker,, Daniel
• Perry, Nicola H.
• Zhang, Yingjie

• Electrochemistry, Electrocatalysis, High-throughput screening, Energy storage, Redox-flow batteries, Scanning electrochemical microscopy, Electrodeposition, Flow-cell, Interfaces.

Statement dc:rights

• Contents of this thesis are pending publication.

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132752

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132752