The current industrial production of hydrogen mainly relies on reforming processes based on fossil fuels, which produce harmful gases like CO and CO2. The best alternative for CO2-free (green) hydrogen production is water electrolysis, ideally coupled with renewable energy sources such as solar and wind. Currently, the highest TRL (Technology Readiness Level) for water splitting is represented by alkaline water electrolyzers (AELs), which allows to produce green hydrogen at current densities lower than 500 mA/cm2, therefore achieving modest productivity. This project aims to develop an efficient and robust cathode and anode combination (i.e. catalytic technology) for water splitting in AEL, enabling higher productivity rates and improved energy efficiency. Thanks to the development of novel Hydrogen Evolution Reaction (HER) catalysts, our AEL reaches current densities as high as 1 A/cm2 and 3.6 A/cm2 at high energy efficiency of 86.9 % and 73.4 % (based on the hydrogen higher heating value-HHV), respectively. To the best of our knowledge, these performances overcome the current state of the art in AELs. The durability test indicates our AEL can work stably at 1 A/cm2 for over 500 h, under industrially relevant conditions (30 wt% KOH as the electrolyte, 80 oC) and atmosphere pressure (ca. 1 bar). Moreover, according to an internal techno-economic analysis, the final production cost for an ideal 1 MW AEL plant based on our catalytic technology is expected to be US$2.26/KgH2 hitting the target set by the European Commission for the next decade (