Multi-criteria optimization of electrode materials for anion exchange membrane water electrolysis regarding energy demand and material criticality

Anion exchange membrane water electrolysis is a novel technology that is expected to produce hydrogen more efficiently than alkaline water electrolysis and without noble metals, which are required in proton exchange membrane water electrolysis. The latter aspect presents a decisive advantage in times of rising material availability concerns. However, resulting from the early stage of development, different materials are considered for use in anion exchange membrane water electrolysis. This study presents a methodology for a comparative analysis of different electrodes regarding their energy demand and material criticality. The energy demand is determined by measuring polarization curves, while the material criticality is quantified using the GeoPolRisk midpoint and SH2E methods. Based on energy demand and material criticality, a multi-criteria optimization was performed to identify the materials that present the best compromise. The results show that the multi-criteria optimization of different electrodes in terms of energy demand and material criticality provides valuable insights for the evaluation of catalysts and can be used to guide sustainable catalyst development. Among the considered materials, the combination of nickel-molybdenum on carbon paper for the cathode and a stainless steel mesh for the anode represent the optimum compromise when considering energy demand and material criticality equivalently essential.