Hydrogen flux improvement through palladium and its alloy membranes: Investigating influential parameters-A review

Today, the world faces two critical challenges: air pollution and the depletion of fossil fuel supplies. In this condition, hydrogen is an energy carrier with zero pollution and high energy utilization. Thus, the production and purification of hydrogen have been appreciated. The Pd-based membrane separation technology has attracted more attention in the continuous separation and purification of hydrogen in the last decade. Pd-based membranes have significant permeability and exclusive perm-selectivity toward hydrogen. To actual industrialization, Pd membranes must meet numerous performance targets, including rendering high H2 permeance, resistance to hydrogen embrittlement, high chemical/thermal/mechanical stability, and low cost. Studies have shown that various parameters such as alloying, fabrication of supported membranes, performing surface modification on the support, and type of fabrication method can be effective in achieving these targets. This review has covered recent developments concentrating on the most influential parameters to fabricate membranes with high performance for actual industrialization. It can be concluded that by applying Pd alloys using the ELP technique, can be possible to achieve a cost-effective membrane with high hydrogen permeance and hydrogen perm-selectivity on a large scale. In addition, ceramics are the best materials for support and surface modification.