A review on the experimental development and numerical modelling of foam-based catalytic reactors: case of hydrogen applications

Hydrogen (H 2 ) is an advanced renewable energy carrier with the potential to decarbonise multiple sectors. In turn, metal foam and reticulated porous structures are a promising catalyst support material due to their high surface area, efficient mass and heat transfer, and good mechanical stability. This review summarises recent developments and considerations in metal-foam based catalytic reactors for process intensification in various H 2 applications. First, an overview of metal foam manufacturing methods provides an insight into the origin of their unique geometric features, mechanical stability and suitability for catalytic processes. Second, the methods of catalytic metal deposition, including slurry coating, sol-gel method, washcoating, wet impregnation, direct coating and surface treatment, are described. Third, the different types and configurations of foam-based reactors, such as fixed-bed, packed-foam, membrane, microreactors and tank reactors are explored, and their performance is compared. Finally, numerical modelling methods are briefly discussed in order to understand the different approaches used in the simulation and optimisation of processes occurring in the porous medium and metal-foam based reactors. This work addresses the strong potential of metal-foam based catalytic technologies in various aspects of the green H 2 value chain.