Micropores enriched ultra-high specific surface area activated carbon derived from waste peanut shells boosting performance of hydrogen storage

Abstract

This research effectively synthesized peanut shell-derived carbon materials (PWAC-X) with outstanding high specific surface area (SSA) and significant number of microporous structures. As a consequence of optimizing ratio of precursors and KOH, an ultra-high SSA of 3728.06 m2 g−1 and total volume of 2.21 cm3 g−1 for PWAC-4 was achieved, resulting in a remarkable hydrogen storage capacity of 6.36 wt% at 77 K and 40 bar. DFT simulations were further utilized to demonstrate interactions between N/O-containing functional groups (N-5, N-6, –OH, C–O–C) and hydrogen molecules. The hydrogen adsorption process on activated carbon was shown to be an exothermic reaction, and carbon containing N/O functional groups were more suitable for hydrogen adsorption than pure carbon materials. In brief, this study has provided an easy-to-scale-up method for obtaining ultra-high SSA carbon materials to storage hydrogen and addresses an intractable utilization of waste products.