Abstract
Hydrogen storage into multi-walled carbon nanotubes obtained by the decomposition of hydrocarbons using Ni–Li/SiO2 was investigated. The optimized reaction conditions for the synthesis of carbon nanotubes were 873K and W/F = 40 g-cat.h/mol, and carbon nanotubes obtained by C2H6 decomposition were found to exhibit fairly large H2 storage capacity of 1 wt% at room temperature. The storage capacity increased with decreasing temperature and a capacity of 5 wt% was achieved at 77K, with 66% of adsorbed hydrogen being desorbable. Hydrogen adsorption by π orbital in C–C bond coordination is proposed, observing both weakened Raman adsorption C–C peaks and the thermal release of CH4 after H2 storage.