Alloy Solutions for Ammonia Cracking: A Review

Abstract

Hydrogen is a key factor in energy storage and transportation, which will inevitably lead to a substantial increase in demand. Ammonia has emerged as a promising carrier molecule due to its high hydrogen density and the possibility to use existing infrastructures to import hydrogen/ammonia produced from renewable sources (green hydrogen). However, utilizing catalytic ammonia cracking to recover hydrogen from ammonia requires better process understanding and new material solutions as current Ni-catalyst–based reactors are too inefficient and unsuitable for the dynamic requirements of future energy systems. To improve the knowledge base, this work provides a literature overview of the nitridation and degradation of structural materials under ammonia cracking conditions. The dependence of the corrosion rate on a wide range of parameters and the missing database for conditions beyond those similar to the Haber–Bosch process are discussed. Closing these critical knowledge gaps will enable scalable green hydrogen production, supporting the global energy transition and addressing the challenges of climate change.