Author: Diwakar Kashyap (Dutch Institute for Fundamental Energy Research) - Proton exchange membranes water electrolysis (PEMWE) has drawn considerable attention for hydrogen production using intermittent electricity obtained from wind and solar due to compact size, high efficiency, quick response time, and high purity of hydrogen. However, the acidic environment in the PEM creates a harsh operating environment which entails the use of scarce noble metals (Pt and Ir) which account for 38% of the cost of a membrane electrode assembly (MEA). Moreover, the conventional method of MEA manufacturing is a ink-based time consuming multi-step process. To alleviate high raw material cost and improved Ir utilization, herein we proposed a vapor-based single step alternative route to produce catalyst-coated membranes (CCMs) and catalyst coated substrate (CCSs) with low Ir loadings, without compromising in activity or durability. In this work, we examined low loading catalyst coated membrane (CCMs) and catalyst coated substrate (CCSs) fabricated using one-step spark ablation technique. The prepared electrodes were characterized using RBS, ICP, SEM, HR-TEM, XRD, and XPS. The electrodes were employed in a single-cell PEM water electrolyzer and complete performance assessment was performed at 60 °C, focusing both on activity and durability. Our results show that both CCMs and CCSs prepared with spark ablation outperform the commercial CCM despite using considerably less Ir. The experimental findings suggest that spark ablation can considerably reduce the cost of CCMs and CCSs for PEM electrolysis at two levels. First, it allows significant reduction in the amounts of expensive and scarce electrocatalysts (which account for 38% of the CCM cost). Taking into account the simplicity of the process, this technology has also the potential to relieve the high CCM manufacturing costs of conventional approaches, which currently account for 42% of the total CCM cost.
