Optimization and Exploration of A New Anode Catalyst Material for Improving Green Hydrogen Production

• Anwen Underwood, Chemical Engineering, University of Delaware

• Yushan Yan, Chemical Engineering, University of Delaware

Global hydrogen production accounts for nearly 2% of global emissions each year. To reduce hydrogen-related emissions, Anion Exchange Membrane Electrolyzers (AEMELs) are emission-free hydrogen production devices that split water into its elemental components using supplied renewable electricity. However, to reach commercial viability, the total cost of producing hydrogen via this pathway will need to be lowered. Investigating alternative catalyst materials that have pre-existing large-scale supply chains is critical to lowering costs and reaching wide scale adoption. This project takes inspiration from lithium-ion batteries to explore one such material, lithium nickel manganese cobalt oxide (Li-NMC) as an oxygen evolution catalyst material. This catalyst material was first studied by preliminary single-cell AEMEL testing by fabricating Li-NMC anodes via ink spray coating and assembling in an electrolyzer with a standard cathode and ion-conducting membrane. After validating sufficient performance, single-cell testing was continued while varying catalyst loadings and binder-to-catalyst ratios at the anode to determine optimal device performance. Temperature and electrolyte concentrations of the AEMEL cell were also studied and optimized. Additionally, short-term durability tests were performed at varying anode compressions to assess the durability of this material over time. As a result, we developed an optimized Li-NMC anode that achieves a current density of 1.87 A cm-2 at a potential of 1.8 V and a degradation rate of 19.4 µV hr-1. This optimized anode has the potential to drastically lower scaled-up AEMEL costs while improving durability performance.