Ionomer-free nanoporous iridium nanosheet electrodes with boosted performance and catalyst utilization for high-efficiency water electrolyzers

• Published in: Applied catalysis. B, Environmental Vol. 341
• Main Authors: Xie, Zhiqiang, Ding, Lei, Yu, Shule, Wang, Weitian, Capuano, Christopher B., Keane, Alex, Ayers, Kathy, Cullen, David A., Meyer, Harry M., Zhang, Feng-Yuan
• Format: Journal Article
• Language: English
• Published: United States Elsevier 16.09.2023
• Subjects: Green hydrogen production; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Low catalyst loading; Nanoporous iridium nanosheets; PEM water electrolysis; Thin titanium liquid/gas diffusion layers
• ISSN: 0926-3373

Increasing the catalyst utilization efficiency and simplifying electrode fabrication processes are crucial to accelerate development of low-cost proton exchange membrane electrolyzer cells (PEMECs). Here, we develop a facile route to fabricate ionomer-free iridium nanosheet integrated electrodes, in which nanoporous iridium nanosheets (IrNS) with abundant exposed edges and nanopores are deposited on thin titanium liquid/gas diffusion layers (TT-LGDLs) via a low-temperature chemical synthesis strategy. Further, benefiting from high catalytic activity, good electrode conductivity and excellent liquid/gas transport properties, such nanoporous IrNS electrodes with low catalyst loadings require low cell voltages of 1.65 V and 1.78 V at 3000 and 6000 mA/cm2, respectively. More impressively, a stable performance can be well maintained under extremely high current density tests of 5000 mA/cm2, demonstrating the potential of low-loading nanoporous IrNS electrodes in solid-electrolyte based electrochemical conversion cells that require high current density operation.