However, hydrogen harvesting for energy usage is a traditionally expensive solution. Liquid alkaline electrolyzers (AELs)have been operating for over 100 years. Still, they suffer from low current density operation (meaning large systems) and some inherent safety issues from using concentrated caustic. Proton Exchange Membrane Water Electrolyzers (PEMELs) have emerged as a more compact option. Still, they require using costly and rare materials, such as platinum and iridium – and some have questioned how scalable this technology truly is. However, new research on a different method indicates these materials might not be needed after all.
New Developments in Hydrogen Production
William E. Mustain, Ph.D., a professor of Chemical Engineering at UofSC, and a team of researchers, including members of Technetics Group, conducted a series of experiments on 14 commercial and pre-commercial porous transport layers (PTLs) in the AEMEL anode. The PTLs were made from stainless steel and nickel alloys. The primary goal was to determine the properties that led to the best possible AEMEL performance – meaning low voltage operation and the production of Green H2 with low energy input. In the study, eleven of the PTLs – including the top-performing one – were custom-developed by Technetics Group.
The Technetics/USC team developed a Hastelloy PTL with a thickness of less than 300 microns (< 0.3 mm) and a density between 60-65% that would produce the best results for hydrogen separation. As such, Technetics Groups’ Feltmetal FM515 was rolled to a thickness, producing a density within the desired range. These properties allowed for low electrical resistance, low contact resistance, and more optimum water and oxygen transport while remaining a desirable surface for catalyst layer deposition. The best-performing PTL achieved an operating voltage of only 1.64 V at an operating current of 1.0 A/cm2, and the operating voltage was still
< 2 V at 3.5 A/cm2. And the cells achieved low voltage degradation rates. These are very promising results that are among the best reported to date for any electrolyzer system.