Rj. Kalenczuk, THE EFFECT OF COBALT ON THE ACTIVATION OF FUSED IRON CATALYST FOR AMMONIA-SYNTHESIS, Journal of chemical technology and biotechnology, 64(4), 1995, pp. 398-406
BET, scanning electron microscopy, X-ray diffraction, Mossbauer spectr
oscopy, X-ray fluorescence spectroscopy and McBain thermobalance were
used to investigate the effect of cobalt on the reduction behaviour an
d activity of fused iron catalyst for ammonia synthesis. Activity test
s were carried out under 10 MPa in the 350-450 degrees C temperature r
ange. Studies were performed on the traditional multipromoted iron cat
alyst and on the series of catalysts prepared with addition of cobalt.
Addition of cobalt promoted the iron catalyst for ammonia synthesis.
The most active sample was that containing approx. 5.5% wt Co. Cobalt
changed the reduction behaviour of the catalyst. The rate of the surfa
ce change during reduction was higher for the case of the 'cobalt cata
lyst'; however the rate of mass change was higher for a typical iron c
atalyst. The process of reduction was probably followed by the formati
on of an Fe3Co compound and by the surface faceting, with the exposure
of an Fe(111) plane.