Poisoning resistance: challenges for hydrogen storage alloys toward engineering applications

Abstract

Due to the safety and stability of hydrogen storage alloys in the field of large-scale energy storage, it has now become a hot spot of attention for researchers. However, the surface poisoning phenomenon caused by the impurity gas (O2, H2O, CO, etc.) contained in hydrogen is an unavoidable problem in engineering applications. On the one hand, in the process of "manufacturing - storage - transportation" of hydrogen, a small amount of impurity gas is easily mixed into it. On the other hand, producing ultra-high purity hydrogen will significantly increase the cost of hydrogen. Thus, in the face of the impurity gas contained in hydrogen, the only way is to improve the poisoning resistance of the hydrogen storage alloy. Therefore, researchers have carried out a lot of work on the poisoning as well as its coping strategy of hydrogen storage alloys, and have made considerable progress. In order to overcome the influence of the poisoning effect in the engineering application, this review summarizes the interaction rules of poisoning behavior on the surface/interface of hydrogen storage alloys under impurity gases, analyzes the effects on improving anti-poisoning abilities of different modification methods carried on the bulk phase and surface/interface. Notably, the concept of constructing the “hydrogen-permeable” and “impurity gas-barrier” layers is established based on the in-depth discussion of the anti-poisoning strategies. Finally, we propose rational directions for future anti-poisoning modification, hoping to promote the solution of poisoning to some extent.