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Abstract Removal of NO and Hg0 simultaneously was achieved on Nb-modified MnTiO x catalyst. Experimental results revealed that high NO conversion (>95%) and Hg0 oxidation (>95%) in 200–300 °C were available on Mn 0.15 Nb 0.02 TiO x catalyst with a GHSV of 108,000 h−1. The excellent catalytic performance of Mn 0.15 Nb 0.02 TiO x catalyst should be originated from its high reducibility and massive surface chemisorbed oxygen species. Moreover, the introduction of Nb into MnTiO x catalyst greatly enhanced its resistance to SO 2 and H 2 O. Neither gaseous Hg0 nor HgO formed on catalyst surface could affect the NH 3 -SCR reaction. NO had a promotion effect on Hg0 oxidation, while NH 3 was detrimental to Hg0 oxidation owing to the inhibited adsorption of Hg0 by NH 3. Under SCR reaction conditions, an inhibition impact on Hg0 oxidation could be detected, but this negative effect could be avoided by using more catalyst sample. Highlights • Over 95% NO conversion and Hg0 oxidation is available over Mn 0.15 Nb 0.02 TiO x catalyst. • The presence of Nb in Mn 0.15 Nb 0.02 TiO x catalyst could improve is resistance to SO 2 /H 2 O. • The reaction mechanism of simultaneous removal of NO and Hg0 is proposed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • NH 3 treatment could enhance the SCR activity and stability of CeO 2 catalyst. • NH 3 treatment could promote the adsorption of reactant species on CeO 2 catalyst. • The reactivity of ad-NH 3 species on CeO 2 catalyst is improved after NH 3 treatment. Abstract In this study, NH 3 treatment of CeO 2 was found to significantly enhance its NH 3 -SCR performance. The NH 3 -treated CeO 2 was characterized by BET, XRD, TPR and XPS. The obtained results revealed the excellent SCR activity and stability of CeO 2 catalyst treated by NH 3 should be originated from the dropped crystallinity, better reducibility, along with the production of more Ce3+ and surface adsorbed oxygen. Furthermore, in situ DRIFT study has been carried out and the results indicated that the Langmuir-Hinshelwood (L-H) mechanism could be applied for explaining the SCR reaction route over CeO 2 -N. [ABSTRACT FROM AUTHOR]

• NO is removed by using persulfate/limestone slurry. • NO removal process is optimized by RSM. • The maximum value of NO removal efficiency was 85.7%. • Reaction temperature is the most significant factor for NO removal. In this work, NO removal process by using sodium persulfate/limestone slurry was investigated. Based on the response surface methodology, the effects of operation parameters, including reaction temperature, sodium persulfate concentration, initial concentration of NO and the concentration of transition metal ions, on NO removal efficiency were investigated. It was found that reaction temperature was the determining factor in NO removal process among all the variables studied, another significant parameter was the persulfate concentration in the mixed slurry. Moreover, the interaction of the reaction temperature with the persulfate concentration also played an important role for their double activation on the removal process. The proposed model equation using response surface methodology had shown good agreement with the experimental data, with a correlation coefficient (R2) of 0.9511. Through the analysis, it was found that the maximum value of NO removal efficiency (85.7%) could be obtained at the specific reaction temperature (58.3 °C) and sodium persulfate concentration (0.066 mol/L), respectively. Therefore, persulfate/limestone slurry is suitable for efficient NO removal. [ABSTRACT FROM AUTHOR]