Dehydrogenation of dodecahydro-N-ethylcarbazole over spinel supporting catalyst in a continuous flow fixed bed reactor

Dodecahydro-N-ethylcarbazole (12H-NECZ) is considered as one of the most promising liquid organic hydrogen carriers (LOHCs) in terms of hydrogen storage and delivery. Developing dehydrogenation catalysts with high efficiency is of significance for its application on a large scale. Herein, we reported a work on the dehydrogenation of 12H-NECZ over supported spinel catalysts in a continuous flow fixed bed reactor. The influence of active metal of Pt, Pd and Ru was firstly investigated. Then four kinds of spinel (MgAl2O4, NiAl2O4, CoAl2O4 and ZnAl2O4) supporting Pd catalysts were well studied. Pd/MgAl2O4 showed the best performance with a conversion of 98.3% at 180 °C. The characterizations of catalysts evidenced that the good performance was attributed to the strong interaction between Pd and MgAl2O4, which resulted in the smaller Pd particles and more positively charged Pd species. These Pd species were believed to be beneficial for dehydrogenation via weakening the adsorbed strength between Pd and dehydrogenated products. This work provides theoretical guidance for the design of efficient dehydrogenation catalysts.