Date of Award

Summer 2025

Document Type

Open Access Dissertation

Department

Chemical Engineering

First Advisor

Zhenmeng Peng

Abstract

The growing demand for sustainable energy has spurred interest in hydrogen as a clean energy carrier, yet its widespread adoption is limited by storage and transport challenges. Liquid organic hydrogen carriers (LOHCs) offer a promising solution by enabling reversible hydrogen storage through chemical redox reactions under ambient conditions. Compared to conventional thermal methods, LOHC electrochemistry provides improved energy efficiency, operational safety, and integration into electrochemical systems. However, key challenges remain, such as catalyst deactivation, limited redox reversibility, and low system-level performance that hinder broader application. Alcohols like isopropanol (IPA) and cyclohexanol (CHOL), and amines like ethylamine, have emerged as promising LOHC candidates due to their favorable redox properties and compatibility with aqueous electrolytes, expanding LOHC applications from hydrogen storage to active roles in rechargeable and flow batteries.

This work investigates the electrochemical performance of LOHCs in various energy storage configurations, including fuel cell, batteries, and flow batteries. An ethylamine-based regenerative fuel cell was developed, highlighting promising prospects for utilizing ethylamine as a regenerative LOHC under ambient conditions. Additionally, aqueous LOHC batteries using IPA and CHOL achieved high specific capacities and energy efficiencies. To address catalytic limitations, PtCu alloy electrocatalysts were designed to enhance isopropanol electro-oxidation kinetics and stability, as supported by in-situ spectroscopy and density functional theory (DFT) analysis. Furthermore, a hybrid battery design combining aqueous LOHC catholytes with non-aqueous anodes was introduced to overcome voltage and energy density constraints. These studies establish the feasibility of LOHC-based energy systems and provide mechanistic and materials-level insights for advancing next-generation electrochemical storage technologies.

Rights

© 2025, Jinyao Tang

Available for download on Monday, August 31, 2026

Share

COinS