X-Ray study of metallic particle sintering in Pt-NaY zeolite catalysts

Abstract

From the behaviour of the small and wide angle X-ray intensities scattered from 2.98% Pt-NaY catalyst samples, after the latter have undergone different calcination procedures, it is shown that the calcination performed for 4 h at the temperature of 250°C yields very disperse metal particles because the ammonia is completely eliminated without decomposing into nitrogen and hydrogen. Calcining at 300°C, ammonia is eliminated in 10 min through its partial decomposition, which is responsible for metal particle sintering which, moreover, is fully accomplished for a calcination duration of 45 min.