Ru-based catalysts for hydrogenation of N-ethylcarbazole: Progress and prospects.

• This review systematically summarizes the up-to-date advances of Ru based catalysts from typical structures, main synthesis methods and hydrogenation applications of NEC. • The NEC hydrogen storage mechanism of Ru-based catalysts, and relationship between structures and catalytic performance are deeply discussed. • This review paves the way for future research and applications of Ru-based catalysts for hydrogen storage. N-ethylcarbazole (NEC) hydrogen storage is a very effective strategy to realize large-scale safe storage of hydrogen. Therefore, the development of high-efficiency catalysts is crucial to promote NEC hydrogen uptake reaction. Among numerous catalysts, precious metal ruthenium (Ru) has been demonstrated to be a promising catalyst for NEC hydrogenation reduction because of its excellent catalytic activity and good stability. Therefore, this review first summarizes typical structures and synthesis methods of Ru-based catalysts. Then, their latest progress and the catalytic mechanism in NEC hydrogenation is discussed in detail. At last, a few optimistic outlooks and potential challenges are highlighted to guide future research and practical applications of Ru-based catalysts in catalytic NEC hydrogenation. [ABSTRACT FROM AUTHOR]