PROMOTED IRON CATALYST FOR AMMONIA-SYNTHESIS CONTAINING ADDITIONAL PROMOTORS

Effect of various metals (Mo, W, Ce, Co) on catalytic properties of ir on catalysts has been studied. Additional promoters were introduced by impregnation of previously reduced and passivated catalysts with appr opriate solutions. Fused, doubly promoted potassium-free catalyst (K) Al2O3, CaO), as well as a triply promoted commercial one (A) were used as precursors. Activity measurements, carried out in a flow gradientl ess reactor pointed out a positive effect of small quantities of cobal t and tungsten introduced together with potassium into the doubly prom oted catalyst (K). Molybdenum did not effect significantly catalytical activity. Presence of cerium on the iron surface led to the drop in t he reaction rate. Tungsten blaring catalysts were found to be highly r esistant towards overheating.