Review of low temperature water splitting cycles for thermochemical hydrogen production

Given its promising potential to displace fossil fuels and function as an effective energy carrier for storage applications, hydrogen has recently become a leading contender as a sustainable energy carrier. Since pure hydrogen is not commonly found in nature, it must be produced in various ways to supply energy demands. This review investigates the production of hydrogen through water splitting with a particular focus on relatively low temperature thermochemical cycles, which present innovative pathways for future large-scale hydrogen generation. This review is a comprehensive evaluation of thermochemical water splitting methods within the broader context of decarbonization efforts. By assessing various cycles, including Na–O–H, V–Cl, Fe–Cl, Cu–Cl, and Mg–Cl, methodologies are categorized to facilitate comparison and highlight research gaps. © 2024 Hydrogen Energy Publications LLC