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The import of hydrogen and derivatives forms part of many national strategies and is fundamental to achieving climate protection targets. This paper provides an overview and technical comparison of import pathways for hydrogen and derivatives in terms of efficiency, technological maturity and development and construction times with a focus on the period up to 2030. The import of hydrogen via pipeline has the highest system efficiency at 57–67 % and the highest technological maturity with a technology readiness level (TRL) of 8–9. The import of ammonia and methanol via ship and of SNG via pipeline shows efficiencies in the range of 39–64 % and a technological maturity of TRL 7 to 9 when using point sources. Liquid hydrogen, LOHC and Fischer-Tropsch products have the lowest efficiency and TRL in comparison. The use of direct air capture (DAC) reduces efficiency and TRL considerably. Reconversion of the derivatives to hydrogen is also associated with high losses and is not achievable for all technologies on an industrial scale up to 2030. In the short to medium term, import routes for derivatives that can utilise existing infrastructures and mature technologies are the most promising for imports. In the long term, the most promising option is hydrogen via pipelines. [Display omitted] • Comparison of 19 import routes for hydrogen and its derivatives. • Comparative overview of technical key performance indicators such as efficiencies, technology readiness level and time constraints of each pathway. • Identification of the most promising import options via pipeline and ship up to 2030. • Identification of remaining research questions for upscaling import technologies. [ABSTRACT FROM AUTHOR]

In this study, we have investigated the stability of antimony-doped tin oxide (ATO) supported IrRu nanoparticles, as catalyst for the oxygen evolution reaction (OER). Conventional stability tests using a rotating disc electrode (RDE) are demonstrated to lead to distorted results, a fact typically addressed to the massive formation of O 2 gas bubbles which block the catalytic active sites. In agreement with previous results, our investigations suggest that the observed decay in current density is not to be confused with catalyst degradation. To mitigate the limitations of the RDE approach, a gas diffusion electrode (GDE) setup was used instead for the stability measurements. Using a carbon gas diffusion layer (GDL) as substrate for the catalyst film, similar beginning-of-life (BoL) and end-of-life (EoL) activities were observed in the low current density region; however, large disparities were found at larger current densities. For meaningful degradation studies, the carbon GDL had to be replaced by a titanium-based substrate. This way a more accurate assessment of the catalyst stability is demonstrated. Although at steady-state conditions the tested IrRu/ATO catalyst exhibited a slight decrease in current densities with time, the BoL and EoL activities are nearly identical. [ABSTRACT FROM AUTHOR]