Hydrogen Storage of Multi-Walled Carbon Nanotubes Obtained by Decomposition of Hydrocarbon over Ni–Li/SiO₂

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.

Keywords:

• Hydrogen storage
• Carbon nanotube
• Decomposition of C₂H₆
• Ni–Li/SiO₂