Oxidation of ammonia to nitrogen over Pt/Fe/ZSM5 catalyst: Influence of catalyst support on the low temperature activity

Abstract

In this study. Pt/Fe/ZSM5 catalysts were applied to oxidation of ammonia, where the catalysts showed good low-temperature activity (<= 200 degrees C) for converting ammonia into nitrogen. With 1.5% Pt/0.5% Fe/ZSM5 catalyst, we could obtain 81% NH3 conversion and 93% N-2 selectivity at 175 degrees C at the short contact-time of w/f = 0.00012 g min/mL Through the characterization studies using high-resolution transmission electron microscopy (HRTEM) and X-ray spectroscopies (XRD. XPS), we could find that the active species was collaborating Pt/Fe species, which structure and activity were largely influenced by support material - in a positive way by ZSM5, rather than by Al2O3 and SiO2. When using ZSM5 as the support material, Pt was highly dispersed exclusively on the Fe oxide, and the valence state and dispersion of Pt changed according to Fe loading amount. (C) 2012 Elsevier B.V. All rights reserved.