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Mechanism of SO 2 effect on Cu 1-x Fe x CeZr catalysts for simultaneous removal of NO and toluene. [Display omitted] • The correlativity between the the reaction process and sulfur poisoning was studied. • The mechanism effect of SO 2 on the reaction process was studied. • A mechanism for simultaneous removal of NO and toluene was proposed. • The introduction of Fe enhanced oxygen vacancies formation and oxygen mobility. Developing non-vanadium-based SCR catalysts with high performances for simultaneous removal of NO and toluene at low-medium temperatures remains a challenge in addressing SO 2 poisoning. Herein, porous Fe-modified CuCeZr catalysts prepared via KIT-6 hard-templating method was conducted to investigate the simultaneous removal of NO and toluene at low-medium temperatures. A suite of experiments and characterizations was systematically used to probe into the effect of SO 2 on the reaction process. The results indicated that porous Fe-modified CuCeZr displayed excellent performance for simultaneous removal of NO and toluene. The introduction of Fe into CuCeZr enhances both acid sites and redox properties via the redox cycle between Cu2++Ce3+↔Cu++Ce4+ and Fe3++Ce3+↔Fe2++Ce4+ redox cycle. Importantly, Fe incorporation leads to the formation of lattice defects and oxygen vacancies, generating abundant active sites that mitigate the detrimental effects of SO 2 poisoning, and promote the efficient removal of NO and toluene simultaneously. Besides, a mechanism influence of SO 2 on the reaction process for simultaneous removal of NO and toluene at low-medium temperatures was proposed. This mechanism has the potential to provide an effective solution for developing non-vanadium-based SCR catalysts with sulfur resistance. [ABSTRACT FROM AUTHOR]

Mechanism of SO 2 effect on mesoporous CuFeAlZrO x catalyst for simultaneous removal of Hg0 and NO. [Display omitted] • Amorphous CuFeAlZrO x catalysts with mesoporous structure were synthesized via a simple co-precipitation method. • The Cu 1 FeAlZrO x exhibited high catalytic activity and good SO 2 resistance at 275–390 ℃. • The synergistic effect of Cu and Fe tune the redox and acidity property with appropriate balance. • A possible mechanism for SO 2 effect on simultaneous removal of NO and Hg0 at wide temperature was proposed. Mesoporous CuFeAlZrO x catalyst is a promising substitute of V-based catalysts for potential candidate for simultaneous removal of Hg0 and NO due to its excellent performance at a broad temperature range. SO 2 poisoning effects remain a challenge in development of efficient SCR catalysts for applications. In this paper, the effect of SO 2 on mesoporous CuFeAlZrO x catalyst for simultaneous removal of Hg0 and NO at wide temperature range was studied. Relevant characterization techniques of H 2 -TPR, NH 3 -TPD, TG, SO 2 -TPD, XPS, Hg-TPD and in situ DRIFTS were used to reveal the correlativity between the physicochemical properties and SO 2 resistance of CuFeAlZrO x catalysts. SO 2 exhibited an inhibitory effect at low temperature (<300 °C) but a facilitative effect at high temperature(≥300 °C) for NH 3 -SCR reaction. At the same time, a promoting effect on Hg0 removal was observed during the whole temperature range. The deposition of NH 4 HSO 4 and the decrease of redox capacity caused the loss of SCR activity at low temperatures, while the formed iron sulfate provided more Lewis acid sites facilitate the high-temperature SCR performance due to the strong electron withdrawing effect of the S O double bonds. In addition, the generation of iron sulfates and NH 4 HSO 4 on mesoporous Cu 1 FeAlZrO x were alleviated because of the sacrifice of copper sites and promoted NH 4 HSO 4 decomposition in mesopore channels. SO 2 reacted with Hg0 to form HgSO 4 and Hg 2 SO 4 , which contributed to Hg0 removal performance. [ABSTRACT FROM AUTHOR]