Promotion of catalytic performance by adding W into Pt/ZrO2 catalyst for selective catalytic oxidation of ammonia

Pt-WO3/ZrO2 catalyst was prepared by co-impregnation method to improve the ammonia oxidation performance of Pt/ZrO2. Differences in textural, structural, surface chemical states, redox properties and acid properties, together with the catalytic performance of Pt/ZrO2 and Pt-WO3/ZrO2 catalysts were investigated systematically. The results of H-2-TPR revealed that higher reduction ability was possessed by Pt-WO3/ZrO2 than that of Pt/ZrO2 due to the influence of tungsten on platinum. The XPS results showed that electron transfer from tungsten to platinum species made higher electron density around platinum. The TEM results revealed that the active lattice plane Pt[111]was obtained by modification of W species. Consequently, Pt-WO3/ZrO2 exhibited obviously better ammonia oxidation performance compared with Pt/ZrO2, the light-off temperature of NH3 shifted from 284 degrees C to 249 degrees C, the activation energy decreased from 113.4 kJ mol(-1) to 96.2 kJ mol(-1). (C) 2017 Elsevier B.V. All rights reserved.