H2-selective catalytic reduction of NOx activity and microstructural analysis of new BaTi0.95Pd0.05O3 catalyst

Abstract

This work describes the preparation and characterization of a new type of NOx-reduction catalyst where the Pd-ions were incorporated into the BaTiO3 perovskite lattice by the co-precipitation method. Pd-ions were expected to be stabilized at the B-site of the perovskite structure. The purpose of this study was to observe the influence of the newly created active sites on the catalyst’s performance in comparison with those of the conventionally supported Pd-catalysts. The analysis showed that most of the Pd-ions do not replace Ti-sites at the co-precipitated BaTi0.95Pd0.05O3 nominal composition. Despite this fact, the BaTi0.95Pd0.05O3 catalyst displayed a very good performance during H2-SCR of NOx tests. The results displayed peak NOx-conversions of 90% and N2 selectivities between 65 and 85%. The presence of water and carbon dioxide hardly affected the performance of the catalysts, while carbon monoxide competed at the same active sites with NO during the reduction process, thus, negatively affecting the catalyst performance. Under the given H2-SCR conditions, only NO was reduced, but not N2O or NO2 when applied instead of NO.