Synthesis, Structural and Electrochemical Characterization of Honeycomb Supported Pt-Pd-Rh Composite Catalyst for the Decomposition of Gaseous Ammonia to Nitrogen

Abstract

The behavior of the ammonia (NH3) oxidation was by selective catalytic oxidation (SCO) over a honeycomb supported Pt-Pd-Rh composite catalyst in a tubular fixed-bed flow quartz reactor (TFBR) at 673 K. A honeycomb Pt-Pd-Rh composite catalyst was prepared by incipient wetness impregnation with aqueous solutions of H2PtCl6, Pd(NO3)3 and Rh(NO3)3 that were coated on cordierite cellular ceramic materials. The catalysts surface properties were characterized using OM. The experimental results show that contaminants crystal aggregation phases and washcoat loss from high initial concentration of NH3 may be responsible for the deactivation of the catalysts. In addition, the catalytic redox behavior was determined by cyclic voltammetric (CV), which showed that the catalytic behavior is related to the metal oxide properties of the catalyst.