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Cerium samarium oxides catalysts with K+ doping on the wall surface of cordierite honeycomb ceramics were preparation by sol–gel and dipping processes. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform-infrared spectroscopy were used to characterize the structural morphology and phase compositions. Through XPS analysis and H2-TPR measurement of monolithic catalyst, it is found that potassium ions improve the oxygen mobility in CeO2 lattice and form surface active oxygen, increase the amount of oxygen adsorbed on the surface and improve the oxidation–reduction capacity. The catalytic combustion research demonstrates that T10, T50 and Tm in samples (Ce/Sm-0 K, Ce/Sm-0.3 K, Ce/Sm-0.5 K and Ce/Sm-0.7 K) decrease significantly compared with the blank reference (Cordierite). And the optimized sample Ce/Sm-0.5 K possess the lowest T10 (389.6 °C), the lowest T50 (425.5 °C), and the lowest Tm (419 °C) in comparison with other samples. The cycle stability investigation reveals that sample Ce/Sm-0.5 K has excellent structural stability and stable catalytic performance, which has potential application in soot catalytic combustion field. [ABSTRACT FROM AUTHOR]

Na 4 Mn 9 O 18 whiskers were prepared on the wall of cordierite honeycomb ceramics using the molten salt synthesis, and Na 4 Mn 9 O 18 whiskers were grew on channel surface of cordierite honeycomb ceramics to form hierarchical microstructure for catalytic combustion of soot. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used to characterize the structural morphology and phase compositions. Na 4 Mn 9 O 18 whiskers with aspect ratio of 24.4 measured by statistics. It was found that the loading rate of the monolithic catalyst reaches 3.588% while the binding rate after sonication almost no change. Whiskers are tightly combined with the cordierite ceramic substrate by the binding strength experiments and EDS analysis. The oxygen temperature-programmed desorption (O 2 -TPD) measurements were performed to investigate the O 2 adsorption property. The catalytic performance of the samples were examined by semi-quantitative thermal gravimetric analysis (TG-DTG) and temperature-programmed oxidation (TPO). The catalyst performance study demonstrates that Na 4 Mn 9 O 18 whiskers decrease the soot combustion temperature apparently. Experiments show the characteristic temperature could be reduced by increasing the catalyst loading. The Na 4 Mn 9 O 18 decreased the ignition temperature of soot particles oxidation, and the cycle stability experiment confirmed that the sample (0h-m-k) has good structural stability and stable catalytic performance. The coarseness of the interface increased because Na 4 Mn 9 O 18 whiskers grew on the cordierite substrate, and the trapping ability improved. Na 4 Mn 9 O 18 is an important type of catalyst which is rarely studied in catalytic oxidation of soot. This catalyst displays good activity and stability in the soot catalytic oxidation. This unique microstructure has potential application in the DPF field. [ABSTRACT FROM AUTHOR]

Mullite whiskers were prepared on the wall of cordierite honeycomb ceramics using the gas-phase growth method. Subsequently, Co/Ce 0.75 Zr 0.25 O 2 catalyst was loaded on the mullite whiskers to form hierarchical microstructure by the sol-gel technology for catalytic combustion of soot. Scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform-infrared spectroscopy, X-ray diffraction and Transmission electron microscopy were used to characterize the structural morphology and phase compositions. The filtration capability can be improved by mullite whiskers growth on the wall of cordierite honeycomb ceramics, and the microstructural feature is similar to the pseudostratified ciliated epithelium on the tracheal cavity surface (one section of human respiratory system). The Co/Ce 0.75 Zr 0.25 O 2 catalyst decreased the ignition temperature of soot particles oxidation, and the cycle stability experiment confirmed that Co/CZ@M/C sample has good structural stability and stable catalytic performance. The high-efficiency filtration and the low-temperature catalytic oxidation of soot particles are combined with the hierarchical microstructure of Co/CZ@M/C, which has potential application in the diesel particulate filter (DPF) field. [ABSTRACT FROM AUTHOR]

In this paper, potassium titanate whiskers was prepared via the Molten salt synthesis on the surface of cordierite ceramics for the regeneration of diesel particulate filters (DPFs). SEM, EDS, XRD, FT-IR, TG-DSC and TPO were carried out to characterize the morphology, microstructure, growth mechanism and catalytic performance of the samples. Potassium titanate whiskers with diameter (100–500 nm) and length (about 3 μm) is tightly combined with the cordierite ceramic substrate. The catalyst performance investigation demonstrates that potassium titanate whiskers decrease the soot combustion temperature apparently. The soot combustion process was studied by thermal analysis tests, and the activation energy of the combustion reaction can be calculated using Freeman-Carroll method. The carbon oxidation activation energy is 14.009 kcal/mol, and the activation energy for the catalytic reaction with potassium titanate whiskers is 6.287 kcal/mol, it can be illustrated that potassium titanate whiskers/cordierite catalyst possess excellence performance for carbon catalytic combustion. The coarseness of the interface increased because potassium titanate whiskers grew on the cordierite substrate, and the trapping ability could improve. This unique microstructure has potential application in the DPF field. [Display omitted] [ABSTRACT FROM AUTHOR]