Jump to main content
Jump to site search

Issue 8, 2013
Previous Article Next Article

Effects of support pre-calcination on the NOx storage and reduction performance of Pt–BaO/Al2O3 catalysts

Author affiliations

Abstract

Effects of the crystalline structure and surface property of the Al2O3 support on the NOx storage and reduction (NSR) performance of Pt–BaO/Al2O3 catalysts were studied using catalysts prepared from a series of Al2O3 samples obtained by varying the calcination temperature of an Al(OH)3 hydrogel in the range of 450–1000 °C (referred to as the pre-calcination temperature, PCT). The texture, crystalline structure and surface acidity of the Al2O3(PCT) supports were measured employing nitrogen adsorption–desorption, XRD, NH3-TPD and IR spectroscopy of adsorbed pyridine, respectively. The Al2O3(PCT) samples showed a gradual ordering of the γ-Al2O3 phase when increasing the PCT from 450 to 800 °C, and a phase transition from the γ- to θ-Al2O3 phase upon further increasing the PCT to 1000 °C. The surface density of Lewis acid sites of the Al2O3(PCT) samples exhibited a maximum at PCT in the range of 800–900 °C. The NSR performance of Pt–BaO/Al2O3 catalysts derived from the Al2O3(PCT) samples was studied under cyclic lean/rich conditions. The numbers of NOx stored and reduced on the Pt–BaO/Al2O3(PCT) catalysts showed similar volcano-type dependencies on PCT, peaking at PCT = 800 °C. The origins of the support PCT effect were discussed in the light of Pt particle size, the nature of BaO sites and Pt–BaO synergy. It was found that the increase in the crystallinity of the γ-Al2O3 phase and the surface acid site density of the supporting Al2O3 samples would result in improved proximity and synergy between Pt and BaO sites, leading to much more efficient NSR Pt–BaO/Al2O3 catalysts.

Graphical abstract: Effects of support pre-calcination on the NOx storage and reduction performance of Pt–BaO/Al2O3 catalysts

Back to tab navigation

Publication details

The article was received on 28 Sep 2012, accepted on 09 Apr 2013 and first published on 10 Apr 2013


Article type: Paper
DOI: 10.1039/C3CY00228D
Citation: Catal. Sci. Technol., 2013,3, 2062-2071
  •   Request permissions

    Effects of support pre-calcination on the NOx storage and reduction performance of Pt–BaO/Al2O3 catalysts

    Z. Hu, W. Li, K. Sun and B. Xu, Catal. Sci. Technol., 2013, 3, 2062
    DOI: 10.1039/C3CY00228D

Search articles by author

Spotlight

Advertisements