Nitrogen-doped hierarchically porous carbon derived from ZIF-8 and its improved effect on the dehydrogenation of LiBH4

Nitrogen-doped hierarchically porous carbon (NHPC) materials have been synthesized by using a zeolitic imidazolate framework, ZIF-8, as self-sacrificing template. The initial derived carbon (D-carbon) contains a 3-dimensional (3D) hierarchically porous carbon framework with rich nitrogen doping (11.22%). Chemical activation by KOH, the further activated carbon (Ac-carbon) shows a specific high surface area (2477 m(2) g(-1)), but lower N content (1.99%). LiBH4-(D-carbon)/(Ac-carbon) is prepared by ball-milling method and the dehydrogenation performance of LiBH4 is significantly improved. More than 6.13 wt% H-2 can be released from either of the two mixtures within 100 min at 320 degrees C, respectively, showing better dehydrogenation performance than that of pure LiBH4. Additionally, the controlled experiments reveal that those improved dehydrogenation properties of LiBH4 might be attributed to the synergetic contributions of high N heteroatom loading, large surface area and catalysis of carbon materials. We provided a simple method to prepare solely MOF-derived nitrogen-doped carbon materials, which might be a promising catalyst for the hydrogen storage materials. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.