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• The generation of sulfates promoted the formation of a large number of Brønsted acid sites. • Generation of Brønsted acid sites enhanced the activation of NH 3 -adsorption. • The generation of NO 2 led to "fast SCR" reaction over Ce-Ti-S-HT. • NH 3 -SCR reaction over Ce-Ti-S-HT involved E-R and L-H mechanisms. Acid modification played an effective role in modifying Ce-Ti catalysts. Exploring the influence of the preparation method on catalytic activity in NH 3 -SCR was examined. Ce-Ti modified by sulfuric acid was prepared by different methods (co-precipitation, hydrothermal and sol-gel methods). Ce-Ti modified by sulfuric acid was prepared by different methods (co-precipitation, hydrothermal and sol-gel methods) and used to the selective catalytic reduction of NO with NH 3. Results displayed that the Ce-Ti-S-HT catalyst exhibited NO x conversion rates exceeding 90 % at 225–400 °C. The existence of sulfuric acid species could increase in the number of surface acidity sites, especially for the number of Brønsted acidic sites, which resulted in an enhancement of the adsorption ability and an improvement in the selectivity of N 2. Furthermore, higher ratio of Ce3+ over Ce-Ti-S-HT contributed to the superior catalytic performance. Besides, sulfuric acid modification could change the reaction pathway of the catalyst. Sulfuric acid modified Ce-Ti catalysts were investigated in the selective catalytic reduction reaction. The formation of sulfate species, the abundance of Brønsted acid sites could improve the adsorption of NH 3. The generation of NO 2 led to "fast SCR" reaction, resulting in the improvement of catalytic activity. [Display omitted] [ABSTRACT FROM AUTHOR]

The CeMo catalysts were prepared via different method and employed for the catalytic combustion of toluene. The influence of different preparation methods on CeMo samples for toluene oxidation was revealed. The toluene catalytic oxidation efficiency followed an order of CeMo-HT > CeMo-CP > CeMo-Sg. The long-term test indicated that the CeMo-HT possessed outstanding thermal stability. The excellent catalytic activity of CeMo-HT could be reasonably attributed to the smallest grain size, the highest number of low valence Ce3+ ions and O sur species. CeMo-HT catalyst prepared by the hydrothermal method possessed the richer oxygen vacancies, which promoted the deep oxidation of toluene, and effectively reduced the production of intermediates. However, CeMo-HT (aged) possessed poorer oxygen vacancies, and generated more by-products. Additionally, the two reaction pathways of the toluene were inferred. In pathway I for CeMo-HT (aged): toluene → benzyl alcohol → benzaldehyde → benzoic acid →carbonate → CO 2 and H 2 O. In pathway II for CeMo-HT: toluene → phenol → benzoquinone → maleic anhydride → CO 2 and H 2 O. [Display omitted] • CeMo-HT sample exhibited best catalytic activity and stability for toluene oxidation. • Superb activity was attributed to high Ce3+/ Ce4+ and high O Sur /O total. • The oxygen vacancies were simply modulated by the preparation method. • Benzoic acid and phenol were key intermediates in toluene catalysis by in situ infrared analysis. [ABSTRACT FROM AUTHOR]