Ru-Based Catalysts For Ammonia Decomposition: A Mini-Review

Ammonia with a hydrogen content of 17.6 wt % is viewed as a promising hydrogen carrier because the infrastructures for its production, storage, and transportation have been well established. The challenge is that currently the straight production of H-2 from NH3 only works at high temperatures. To date, various metal-based catalysts have been developed for NH3 decomposition, among which the Ru-based ones are the most superior due to the suitable Ru-N binding energy. In the past decade, efforts have been put in to improve the performance of Ru-based catalysts, and the target is to lower Ru loading and reaction temperature. A large variety of support and promoter materials were studied, and advanced techniques were employed to disclose the relationship between catalytic performance and catalyst structure. In this paper, we conduct a review on the materials that are used as supports and/or promoters, focusing specifically on the carbon (CNTs, CNFs, and graphene) and metal oxide (Al2O3, MgO, SiO2, and others) materials. Moreover, the reaction mechanism for ammonia decomposition over Ru-based catalysts is described, and future works on designing novel catalysts and unravelling the catalyst structure-activity relationship are proposed.