In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 10, No. 13 ( 2022), p. 7122-7129
Abstract:
Sodium borohydride (NaBH 4 ) has been widely regarded as a potential hydrogen storage material due to its high gravimetric and volumetric capacity. Its practical application, however, is hindered by the high operating temperature of over 500 °C and extremely poor reversibility. Herein, thermodynamically favored reversible hydrogen storage performance of NaBH 4 is developed inside of bimetallic (NiCo) nanoporous carbon nanosheets. Benefiting from the synergetic effect of nanoconfinement and the catalytic role of NiCo alloys, the apparent activation energy for H 2 desorption from NaBH 4 @NiCo-NC is reduced to 36.8 kJ mol −1 with the complete H 2 desorption at only 400 °C, resulting in the simultaneous formation of NiB and CoB as the dehydrogenation products. More interestingly, the reversible transformation between NiB/CoB and Ni 2 B/Co 2 B that are in situ formed during the subsequent re-/dehydrogenation process acts as a B reservoir, leading to a significant decrease of Gibbs free energy change for the reversibility of NaBH 4 to 1.41 eV, 0.62 eV lower than that of pure NaBH 4 . As a result, coupled with the catalytic role of in situ formed Co 2 B/Ni 2 B in promoting the H 2 desorption performance of NaBH 4 , a stable reversible capacity of 9.0 wt% is realized for NaBH 4 at a temperature as low as 400 °C for 5 cycles.
Type of Medium:
Online Resource
ISSN:
2050-7488
,
2050-7496
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
2702232-8
Permalink