Co-production of hydrogen and multi-wall carbon nanotubes from ethanol decomposition over Fe/Al2O3 catalysts

The co-production of hydrogen and carbon nanotubes (CNTs) from the decomposition of ethanol over Fe/Al₂O₃ at different temperatures and feeding rates of ethanol was investigated systematically. The results indicated that Fe/Al₂O₃ was a quite active catalyst for the co-production of hydrogen and CNTs and that its activity and stability depended strongly on the Fe loading. Among all catalysts tested, 10 mol% Fe/Al₂O₃ was the most effective catalyst based on the ratio of hydrogen production, the total H₂ yield, and the quality of the CNTs formed. The efficiency of hydrogen production from ethanol decomposition over 10 mol% Fe/Al₂O₃ reached a maximum of ∼80% at 800 °C and the yield of CNTs with well-oriented growth and uniform diameter was 141%. In addition, the reaction of hydrogen and CNTs co-produced from ethanol decomposition was proposed.