Exploring heterogeneous rate constants, lanthanide separation, catalysis, and baseline correction with graphical methods
Creators: name: Dadallagei, Kasun Saweendra Rathnatunga
Publisher: name: University of Iowa
Year: 2026
Subjects: Electrochmistry
Lanthanide mixtures
public abstract

description: Electrochemical experimentation plays a pivotal role in the analysis of catalysis and provides valuable insights into rate constants and electrochemical processes. This study aims to enhance the understanding of electrochemical data analysis by employing both classical and graphical methods. By delving into the intricacies of electrochemical analysis, the study seeks to refine the approach to experimentation, ultimately advancing knowledge and capabilities in the field of electrochemistry.
description: Electrochemical impedance spectroscopy (EIS) analysis of iron (III) perchlorate: Electrochemical impedance spectroscopy (EIS) is employed to investigate the effects of magnetic fields on iron(III) perchlorate electrochemical systems. Previous studies have shown that the introduction of magnetic micro particles into ion exchange polymers on electrode surfaces can significantly enhance the catalytic activity of metal tris bipyridine complexes. This enhancement is attributed to improved kinetics in both heterogeneous exchange rate and self exchange rate processes. In this research, the focus is on quantifying the impact of magnetic fields on heterogeneous rates by comparing magnetically modified electrodes with the demagnetized magnetic counterparts using EIS analysis.
description: Lanthanide separation an application of the optimized waveforms: The increasing utilization of lanthanides in various applications, including catalysis and electronics, has led to a growing accumulation of lanthanide waste materials. Developing an efficient and precise method for lanthanide separation is essential to address this issue. Electrochemical separation methods offer advantages such as precision, lower maintenance requirements, and simplified production line setup compared to alternative approaches. However, conventional thermodynamic limitations pose challenges to achieving a 99% separation of certain lanthanides. This work explores the application of optimized waveforms, as developed by Dr. Daniel Parr IV, to overcome the thermodynamic limitations associated with lanthanide separation. By leveraging kinetic parameters, these optimized waveforms aim to achieve separations in cases where conventional thermodynamics fall short. Experimental results obtained through the application of these waveform approximations suggest the effectiveness in lanthanide separation, offering a promising solution to address the increasing accumulation of lanthanide waste materials.
description: Lanthanide mixtures in oxygen reduction reaction: This thesis chapter delves into the exploration of lanthanide mixtures as potential catalysts for the oxygen reduction reaction (ORR), a key process in fuel cells and other electrochemical applications. The primary objective is to identify cost effective alternatives to platinum based catalysts, which, despite the platinum based catalysts efficiency, platinum based catalysts are economically prohibitive as the end goal of the study is to create a cost effective ethanol fuel cell. This research focuses on utilizing lanthanide based catalysts, specifically combinations of ytterbium and lanthanum, to enhance ORR. The experimental approach involves electrochemical testing using glassy carbon electrodes modified with a lanthanide mixture. Various electrochemical techniques, including chronocoulometry (CC) and linear sweep voltammetry (LSV), are employed to assess the catalytic activity and efficiency of these lanthanide mixtures. The results indicate notable improvements in current density and inconsistent improvements of onset potentials when lanthanides are used, suggesting lanthanides mixtures potential as effective ORR catalysts. The findings present an initial step towards more sustainable and cost effective solutions for ORR catalysis, with lanthanide mixtures offering a promising avenue for future research in energy conversion technologies.
description: Development of polymer electrodes for 3D printing and molding: The field of electrochemistry continually seeks cost effective electrode materials tailored to diverse applications requiring versatile shapes and forms. Polymer electrodes emerge as promising solutions to address these varied requirements, with a primary focus on two polymers, ABS (acrylonitrile butadiene styrene) and PLA (polylactic acid). These polymers offer affordability and versatility and can be readily modified with carbon or graphene to provide conductivity. This research presents preliminary research on the behavior and potential applications of ABS and PLA polymer electrodes. The study explores suitability for use in electrochemical systems, with a particular emphasis on adaptability to 3D printing and molding processes, providing insights into practicality and feasibility in various electrochemical applications.
description: New perspectives from classical transition state theory: The hydrogen evolution reaction on metal electrodes: A fresh perspective on hydrogen evolution reactions (HER) emerges when classical transition state theory is applied to this field. Trasatti's groundbreaking work revealed that the exchange current density, denoted as j_{0}, exhibits an exponential increase in relation to the metal electrode work function, represented as \Phi. This observation is rooted in the description of the elementary electron transfer step: M(e)+H_{ads}^{+}\rightleftarrows M(0)+H_{ads}^{\bullet} which highlights the crucial role of the metal in the transition state. Leads to the formulation of rate equations that explicitly incorporate the material specific physiochemical property \Phi. One striking finding is the linear correlation between the logarithm of j_{0} and \Phi, a quantifiable relationship that sheds light on the influence of \Phi on j_{0}. Specifically, \Phi elevates j_{0} by reducing the activation energy required for electrocatalysis. These rate expressions, enriched with material specific physiochemical properties, open up exciting opportunities for a priori electrocatalyst design and offer profound insights into the intricate realm of electron transfer kinetics. By revisiting established HER data through the lens of classical transition state theory, this research presents novel perspectives that enrich our understanding of this critical electrochemical process.
description: Graphical method to correct for baselines distorted by subsequent electrochemical processes using the cyclic voltammetric origami method: In a typical cyclic voltammetric (CV) experiment aimed at determining peak currents, it is crucial to establish a baseline. Traditionally, this baseline is derived from the forward direction of the potential sweep. However, scenarios may arise where determining the baseline becomes challenging or even impossible. In cases where voltammograms exhibit significant symmetry, a clever approach can be employed: flipping the voltammograms to deduce the forward baseline from the reverse baseline. This operation relies on fundamental mathematical transformations. To apply this method successfully it is essential that the peak symmetry is symmetric, which is typically the case for reversible to quasireversible electron transfer processes. For highly irreversible transfer processes, the effectiveness of this correction method diminishes. This correction technique is demonstrated through digital simulations for both single (E) and sequential (EE) electron transfer reactions. The practical utility of using flipped axes as a valuable tool becomes evident in situations where establishing the baseline poses challenges for example, where the voltammogram is recorded on approach to the solvent window.