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In this work, a series of mesoporous Ni x Mn 6- x Ce ternary oxides were prepared to investigate their NO catalytic oxidation ability. The sample Ni 2 Mn 4 Ce 4 showed a 95% NO conversion at 210 °C (GHSV, ∼80 000 h -1 ). Characterization results showed the good catalytic performance of Ni 2 Mn 4 Ce 4 was due to its high specific surface area, more surface oxygen and high valance manganese species, which can be ascribed to the incorporation of three elements. Based on the results of XRD, H 2 -TPR, O 2 -TPD and XPS, we confirmed the existence of Ni 3+ + Mn 3+ → Ni 2+ + Mn 4+ , Ce 4+ + Ni 2+ → Ce 3+ + Ni 3+ in Ni 2 Mn 4 Ce 4 , and the oxidation-reduction cycles were proved to be helpful for NO oxidation. The results from an in situ DRIFTS study indicated the presence of bidentate nitrate and monodentate nitrate species on the catalyst's surface. The nitrate species were proved to be intermediates for NO oxidation to NO 2 . A nitrogen circle mechanism was proposed to explain the possible route for NO oxidation. Nickel introduction was also helpful to improve the SO 2 resistance of the NO oxidation reaction. The activity drop of Ni 2 Mn 4 Ce 4 was 13.15% in the presence of SO 2 , better than Mn 6 Ce 4 (25.29%)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this study, different preparation methods including an oxalate route, a nano-casting strategy and a traditional co-precipitation route were applied to obtain MnOx-CeO 2 mixed oxides for selective catalytic reduction (SCR) of NO with NH 3 . The catalyst prepared from the oxalate route showed improved performance for NOx conversion and SO 2 + H 2 O durability. To further improve the SO 2 and H 2 O resistance of catalysts, ternary oxides were prepared from the oxalate route. The catalysts were studied by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), NH 3 temperature-programmed desorption (NH 3 -TPD), SO 2 temperature-programmed desorption (SO 2 -TPD), and in situ diffuse reflectance infrared fourier transform spectroscopy ( in situ DRIFTS). The nickel-manganese-cerium ternary oxide showed the best SO 2 and H 2 O durability. The reason can be ascribed to its smaller pores, amorphous structure, and moderate amount of surface Mn 3+ /oxygen species, which could decrease chemical adsorption of SO 2 ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this paper, ZnS one-dimensional (1D) nanostructures including tetrapods, nanorods, nanobelts, and nanoslices were selectively synthesized by using RF thermal plasma in a wall-free way. The feeding rate and the cooling flow rate were the critical experimental parameters for defining the morphology of the final products. The detailed structures of synthesized ZnS nanostructures were studied through transmission electron microscope, X-ray diffraction, and high-resolution transmission electron microscope. A collision-controlled growth mechanism was proposed to explain the growth process that occurred exclusively in the gas current by a flowing way, and the whole process was completed in several seconds. In conclusion, the present synthetic route provides a facile way to synthesize ZnS and other hexagonal-structured 1D nanostructures in a rapid and scalable way.