Rj. Kalenczuk, THE EFFECT OF COBALT ON THE REACTANTS ADSORPTION AND ACTIVITY OF FUSED IRON CATALYST FOR AMMONIA-SYNTHESIS, Catalysis letters, 33(3-4), 1995, pp. 255-268
Modern adsorption study facilities as well as scanning electron micros
copy, X-ray diffraction, Mossbauer spectroscopy and X-ray fluorescence
spectroscopy were used to investigate the effect of cobalt on the ads
orption of nitrogen, hydrogen and ammonia on the surface of cobalt mod
ified iron fused catalysts. Adsorption studies were carried out at the
temperature range specific for ammonia synthesis (385 degrees C). Act
ivity tests were carried out under 10 MPa in the 350-450 degrees C tem
perature range. Investigations were performed on the traditional multi
promoted iron catalyst and on the series of catalysts prepared with ad
dition of cobalt. Introduction of cobalt changed considerably the samp
le behaviour during activation and ammonia synthesis. Addition of coba
lt promoted the iron catalyst for ammonia synthesis. The most active s
ample was that containing approximately 5.5 wt% Co. Cobalt changed the
adsorption behaviour of the catalyst. Chemisorption of nitrogen is mu
ch higher for ''cobalt'' catalysts. Growth of nitrogen chemisorption a
nd decrease of ammonia adsorption resulted in the growth of catalytic
activity of ''cobalt'' catalysts in ammonia synthesis.