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Developing efficient and stable catalysts for synergistic removal of NOx and dioxin has always been key for controlling air pollution. For this, the hydrotalcite-like structured Cr(x)/LDO catalysts were successfully synthesized for synergistic removal of NOx and o-DCB using a co-precipitation method. The performance test results show that the Cr(0.25)/LDO catalyst has the best catalytic performance, and the NOx and o-DCB conversions are 89% and 82% at 250 °C, respectively. In addition, the reaction mechanism of NH3-SCR and o-DCB catalytic oxidation on the surface of the Cr(0.25)/LDO catalyst, and the interaction between the two reactions were investigated by designing in- situ DRIFTS experiments. The results indicate that the NH3-SCR reaction follows both E–R and L–H reaction mechanisms. The reaction pathway for the o-DCB oxidation process is proposed: o-DCB → chlorinated phenolate → benzoquinone → maleic acid, formic acid, acetic acid, etc. → H2O, CO2, HCl. Moreover, there are interactions between NH3-SCR and catalytic oxidation of o-DCB. At low temperature, there is obvious competitive adsorption between NH3/NO and o-DCB. The competitive adsorption between NH3/NO and o-DCB leads to the decrease of the o-DCB conversion. At high temperature, NH3-SCR and o-DCB oxidation exhibit a synergistic effect, NO2in situ-generated from the oxidation of NO can further participate in the o-DCB oxidation and reduce the accumulation of o-DCB oxidation intermediates on the catalyst surface. The research results contribute to understanding the reaction processes of Cr(x)/LDO catalysts and provide support for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prussian blue analogue derived CeCoO x -PVP@TiO 2 catalyst is prepared for synergistic elimination of NO x and o -DCB. • The addition of PVP enhances the low-temperature redox properties of the catalysts. • TiO 2 coating enhances the acidity of the catalysts and protects the CeCoO x core. • 90% of NO x conversion and 92% of o -DCB conversion are obtained at 300 ℃. Achieving efficient selective catalytic reduction (SCR) of NO x and catalytic oxidation of dioxins (o-dichlorobenzene as a model) on one catalyst is still a big challenge. In order to balance the N 2 selectivity of SCR and the catalytic oxidation of dioxins, the catalysts with suitable redox properties and acidity need to be designed. Herein, we synthesized Prussian blue analogue (PBA)-derived CeCoO x oxides for the simultaneous removal of NO x and o -DCB by a co-precipitation method. The crystallization rate of PBA was slowed down by the addition of Polyvinylpyrrolidone (PVP), which increased the oxides size, enhanced the crystallinity of oxides and the uniformity of the surface elements distribution. These structural effects enhanced the low-temperature redox performance of the catalysts, and thus improved o -DCB conversion and CO 2 selectivity. Furthermore, the PBA structure was coated by introducing TiO 2 , which improved the amounts of medium-acids and the mobility of oxygen species, thus increasing the mid-and high-temperature SCR performance and N 2 selectivity. In addition, the H 2 O resistance and stability of the catalysts were enhanced due to the protective effect of the TiO 2 coating on the PBA core. The optimized CeCoO x -PVP@TiO 2 catalyst exhibited stable bifunctional removal efficiencies for NO x and o -DCB, with 90% NO x conversion and 92% o -DCB conversion at 300 ℃. The possible reaction mechanisms for NH 3 -SCR and the catalytic oxidation of o -DCB over the CeCoO x -PVP@TiO 2 catalyst were proposed based on in situ DRIFTS experiments. This work provides an efficient strategy to design advanced catalysts for the elimination of dioxins and NO x. [ABSTRACT FROM AUTHOR]

• The research progress of manganese based oxide catalysts is reviewed. • How to improve the catalytic performance of VOCs was analyzed. Previous studies have confirmed that catalytic oxidation is a promising and effective technology for treating volatile organic compounds (VOCs). Manganese-based catalysts are characterized by high catalytic activity, relatively low cost, long durability, structural diversity. And as an environmentally friendly material, they are therefore one of the most competitive materials in the field of catalytic oxidation of volatile organic compounds. Despite the potential for a wide range of applications, the use of manganese-based catalysts is limited by deactivation and sintering sensitivity, which may affect their long-term performance thus limiting their use in industry. In this paper, we summarize the relevant progress of the current research from four aspects: single manganese oxides, composite manganese-based oxides, acid-treated manganese catalyst surfaces, and Mn-based perovskite catalysts. Compared to single manganese oxides, manganese-based composite catalysts exhibit enhanced activity and stability due to synergistic interactions between the metals. And adjusting the carrier can obtain a larger specific surface area, better dispersion of metal active sites, and enhance the synergistic interaction between the active sites and the carrier, thus obtaining better catalytic performance. Acid treatment, on the other hand, can change the catalyst surface chemistry such as metal oxidation state, reactive oxygen species and structural defects, and Mn-based perovskite are widely used due to their flexible composition, good redox properties, good thermal stability, and relatively low price. Finally, the problems and prospects of Mn-based oxide catalysts for catalyzing the combustion of VOCs are presented to provide ideas for further design of new and efficient low-temperature catalysts. [ABSTRACT FROM AUTHOR]