Progress of ammonia electro-oxidation catalysts for direct ammonia alkaline fuel cells

Abstract

At present, hydrogen fuel cells are one of the effective means to solve energy and environmental problems, but the problem of hydrogen storage and transportation is difficult to break through. Ammonia is a carbon-free hydrogen-rich compound, which also has the advantages of high bulk density and easy storage and transportation, and is an ideal fuel to replace hydrogen as a battery. However, at present, the preferred ammonia electro-oxidation catalyst for direct ammonia alkaline fuel cells is still platinum, and its expensive price is the main problem that hinders the wide application of direct ammonia alkaline fuel cells. Therefore, the design of low-cost and high-efficiency catalysts is a necessary task for commercializing direct ammonia fuel cells. In this paper, we firstly review the progress of researchers in ammonia electrooxidation mechanism in recent years, focus on reviewing the current research status of Pt catalysts and non-Pt catalysts for direct ammonia alkaline fuel cells, and finally suggest future research approaches to address the existing problems, aiming to provide ideas for designing more efficient, stable and cheap ammonia electrooxidation catalysts in the future.