Synthesis and application of Ni-based membranes in hydrogen separation and purification systems: A review

Membrane technology has emerged as an attractive research orientation in hydrogen purification systems and research is focused on producing highly stable, sustainable, and hydrogen-selective membranes. The high -temperature tolerance and low cost of Ni-based membranes have led to increased interest in their application in high-temperature separation and purification systems for hydrogen production. Various studies have been devoted to investigating the solubility, diffusivity, and permeability of nickel to hydrogen. This review provides an overview of the synthesis and applications of Ni-based membranes. The information is divided into different sections including: (i) a general introduction which provides information on why nickel metal is the preferred choice in membranes for hydrogen purification and the mechanism for hydrogen diffusion through these membranes; (ii) dense and porous nickel membranes types are reviewed; (iii) we then critically analyze and evaluate different techniques that are used in fabricating nickel-based membranes; (iv) in addition, this review seeks to uncover the nature of the catalytic effects of nickel-based membranes for ultrapure hydrogen production; (v) we further review the application of these membranes in the reforming, water gas shift, and dehydrogenation reactions to highlight their use in hydrogen purification systems. The effects of membrane properties and reactor configuration are detailed in the last section. Studies devoted to the applications of nickel membranes in multi -component systems remain very limited, most researchers investigated two-component systems, and these do not mimic real life applications. Furthermore, the potential and opportunities offered by catalytic nickel-based membranes need to be further explored.