Poisoning Resistance for Metal Hydride Hydrogen Storage Materials: Mechanism, Strategies, and Challenges

The safe and stable storage and transportation of hydrogen is a bottleneck problem for hydrogen energy development. Metal hydrides (MHs), hydrogen storage materials, have been widely applied due to their excellent hydrogen storage performance. However, hydrogen storage alloys are susceptible to surface contamination by impurity gases (such as O 2 , H 2 S, CO, CO 2 , CH 4 , N 2 , and so on.) in practical applications, which can drastically destroy the hydrogenation performance. Therefore, understanding the poisoning mechanisms of MH hydrogen storage materials and developing effective poisoning mitigation strategies has become an important topic. This review summarizes the microscopic mechanisms and poisoning factors of hydrogen storage alloys and systematically introduces major poisoning mitigation strategies, including surface modification, composition optimization, and nanomaterial modification, etc. Finally, a detailed analysis of these challenges is provided for guiding future research and development efforts. By addressing the poisoning challenge, we can pave the way for the widespread adoption of MH materials in hydrogen energy technologies.