Production of Hydrogen and Nanocarbon from Catalytic Decomposition of Methane over a Ni–Fe/Al2O3 Catalyst

• Published in: Energy & fuels 2013-08, Vol.27 (8), p.4448-4456
• Main Authors: Wang, Gaowei, Jin, Yi, Liu, Guojuan, Li, Yongdan
• Format: Article
• Language: English
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef3019707

A Ni–Fe–Al catalyst derived from a hydrotalcite-like structured precursor prepared with a co-precipitation technique is employed in the methane catalytic decomposition reaction producing carbon nanofibers (CNFs) and CO x -free hydrogen. The effect of doping with iron on the activity and stability is investigated. The performance of the catalyst is evaluated with a temperature-programmed reaction and a constant temperature reaction. The catalyst with a Ni/Fe/Al mole ratio of 2:1:1 shows an extremely stable activity and is still active after 210 h of reaction. The carbon yield on this catalyst reaches 562 g of C/g of catalyst. The post-reaction characterization results indicate that the Ni–Fe alloy is formed in the Ni–Fe–Al catalyst and is proposed to be the active phase for the CNF growth. The addition of an appropriate amount of Fe may enhance the carbon diffusion rate and decrease the carbon formation rate. Thus, the balance among the carbon atom formation, diffusion, and precipitation rates is maintained, and the stability of the catalyst is enhanced.