%0 Journal Article
%T Catalytic Soot Oxidation Activity of NiO每CeO2 Catalysts Prepared by a Coprecipitation Method: Influence of the Preparation pH on the Catalytic Performance
%J Materials | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/ma12203436
%X A series of NiO每CeO 2 mixed oxide catalysts have been synthesized by a modified coprecipitation method at three different pH values (pH = 8, 9, and 10). The NiO每CeO 2 mixed oxide samples were characterized by TGA, XRD, inductively coupled plasma atomic emission spectroscopy (ICP-AES), FTIR, Brunauer每Emmett每Teller (BET) surface area, H 2 temperature-programmed reduction (H 2-TPR), and electron microscopy (high-angle annular dark-field transmission electron microscopy/energy-dispersive X-ray spectroscopy (HAADF-TEM/EDS)). The catalytic activities of the samples for soot oxidation were investigated under loose and tight contact conditions. The catalysts exhibited a high BET surface area with average crystal sizes that varied with the pH values. Electron microscopy results showed the formation of small crystallites (~5 nm) of CeO 2 supported on large plate-shaped particles of NiO (~20 nm thick). XRD showed that a proportion of the Ni 2+ was incorporated into the ceria network, and it appeared that the amount on Ni 2+ that replaced Ce 4+ was higher when the synthesis of the mixed oxides was carried out at a lower pH. Among the synthesized catalysts, Ni-Ce-8 (pH = 8) exhibited the best catalytic performance. View Full-Tex
%U https://www.mdpi.com/1996-1944/12/20/3436