Karla Schall Colle

Nickel-catalysed carbon gasification: Crystallographic and magnetic studies☆

Abstract Nickel possesses high catalytic activity for steam gasification of carbon at 810K but shows rapid deactivation at 30–50% carbon conversion. In an attempt to understand the mode of deactivation, the crystallographic and magnetic properties of finely divided nickel particles on carbon were determined as a function of gasification conditions. X-ray analyses showed that nickel particles increased in crystallite size with carbon gasification. Magnetic studies related the observed ferromagnetic moment to crystallite size and the degree of metal reduction. Catalyst deactivation was shown to be partially due to crystallite growth and loss of nickel-carbon contact. Furthermore, catalyst activity was shown to be related to the presence of oxidized nickel species. Catalyst deactivation due to nickel oxide formation or carbon dissolution has been ruled out.