The need for de-carbonization of our society is a pressing issue raising the attention at social and political levels. The production of high value chemicals and fuels such as methanol requires hydrogen derived at the moment from hydrocarbons and resulting in large emissions of CO2. Green Hydrogen produced by water electrolysis coupled to renewable sources could be the ultimate solution to this problem. Proton exchange membrane water electrolysis (PEMWE) is the most suitable technology for this process due to its compactness and flexibility. However, the dependence on precious metal catalysts and expensive components manufactured in titanium poses a serious threat for the scale up and market penetration of this technology. PROMET-H2 project aims to develop a pressurized PEMWE with the lowest capital cost ever achieved. The main objective of PROMET-H2 project is to decrease the capital cost of the PEMWE from 1000-1500 €/kW to 500-700 €/kW without compromising its performance and durability, and replacing noble metals with others that are more benign from an environmental and economic point of view. The main ambition in PROMET-H2 is to place PEMWE as the technology of choice for production of H2 for storing renewable energy and being a competitive alternative for large scale storage, by maintaining a balance between economic/costs and environmental aspects. PROMET-H2 overall ambition will be tackled by i) developing advanced materials, including CRM-free catalysts, ii) coatings for stainless steel PTL and BPP, iii) thin membranes to reduce PEMWE cost without affecting the current KPIs performance and durability and iv) by using new stack designs to obtain more efficient PEMWE being able to reduce the system and process costs. Conclusions. PROMET-H2 has developed a PEMWE stack with a reduction in the capital costs and CRM, the significantly reduced use of critical raw materials will mitigate the limitation of material availability for the large-scale deployment of water electrolysis. CCMs with low Ir loading based on Ir on ATO have been developed achieving project target 2 Acm-² at 1.9 V with 0.2 mgIrcm-² with 1000h stable operation. Stainless steel as base material for manufacturing PTL has successfully developed. The reduction in use of CRMs is further strengthened by developing versatile and environmentally friendly recycling procedures using hydrometallurgical process, recovery rates (100% Pt, 60% Ir). In addition to the materials development, PROMET-H2 has developed a tool for testing locally the homogeneity in the current density distributions and temperatures at stack level.
