NEW MECHANISM FOR LENGTHENING THE LIFETIME OF HYDROGENATION CATALYSTS

Intermetallic compounds with d-transition metals have been used as catalysts. XPS and AES studies and the magnetic properties of LaNi5 and FeTi show that surface segregation occurs and that superparamagnetic Ni and Fe precipitates are formed at the surface, catalyzing the dissociation of molecular hydrogen. The catalytic activity of many intermetallic compounds can be explained by surface segregation and the formation of d-transition metal precipitates. Contaminants often drive the segregation, hereby prolonging the lifetime of the catalyst. We predict that FeTi can replace Fe-catalysts being more resistant to contaminants. © 1979.