Nitrogen isotope exchange on the catalyst of ammonia synthesis

To gain more information on the mechanism of ammonia synthesis on a commercial iron catalyst (Fe promoted with Al2O3 and K2O), a study has been made into the isotopic exchange of nitrogen chemisorbed on the catalyst with gaseous nitrogen-heteroexchange, and the homomolecular exchange in gaseous nitrogen (14N)2+(15N)2=214N15N on the catalyst surface containing chemisorbed nitrogen. The nitrogen adsorption and isotopic exchange were conducted at 350 to 500 deg C. The exchange follows an adsorption-desorption mechanism, the total speeds of heteroexchange and homomolecular exchange are equal, and addition of hydrogen does not affect the exchange rate. The surface nitrogen migration is much faster than the isotopic exchange