FTIR characterization of Ru/SiO2 catalyst for ammonia synthesis

Carbon monoxide adsorption on a Ru/SiO(2)catalyst was followed by IR spectr oscopy to investigate the active sites. Using this catalyst, ammonia synthe sis was achieved at 350 degrees C in an N-2/H-2 gas mixture (N-2/H-2 approx imate to 3 : 1) for different reaction times. In addition to NH3 other NH, (x = 1,2) species were also observed. CO adsorption after NH3 production wa s also performed to investigate the change in nature of the active sites. B ased on the experimental evidence participation of Ru-0 sites in ammonia sy nthesis was confirmed and a partial oxidation of the reduced Ru sites durin g the synthesis was observed. (C) 1999 Elsevier Science B.V. All rights res erved.