N-doped Ce0.2Zr0.8O2 catalysts for NO oxidation were successfully fabricated via NH3 treatment at high temperature, and the N doping amount could be controlled via adjusting the conditions of various NH3 concentrations and treatment times. The optimal 10N700-5 catalyst revealed the sensational oxidation efficiency at low temperature, which surpassed 50% at 180 °C and reached up to 82.82% at 270 °C. The excellent activity was ascribed to the numerous generations of O2 – and the accompanied vast formation of Cr6+, caused by N doping. N atoms were doped in Ce0.2Zr0.8O2 in the structure of Ce–O–N–O–Zr via the O–N–O bond between N and O. The analysis of affecting factors elucidated that cation ratios played a more significant role than the Brunauer–Emmett–Teller surface area, and Cr6+ ratios acted mostly. Additionally, the conceivable promotion mechanism by N doping for NO oxidation was examined via in situ DRIFTS. This work propelled denitration with the selective catalytic oxidation technique for industrial application and lent a novel perspective for the design of catalysts with satisfied oxidation efficiency at low temperature.

CO 2 hydrogenation is the most efficient way to achieve the goal of "Carbon Neutral," and the transition metals (Mn, Co, Ni, Cu)embedded faveolate ZnFe 2 O 4 were fabricated and then evaluated with a CO 2 hydrogenation test. The systematic investigation of the effect of the introduced transition metals on the catalytic performance revealed that the activity was influenced by the surface structure, especially by the surface FeÀ C percentages. The introduction of Zn could increase CO 2 adsorption, thus promoting the reverse water gas shift (RWGS) reaction, which is considered the first step during CO 2 hydro-genation. The surface FeÀ C species played a significant role during the Fischer-Tropsch (FÀ T) synthesis, specific to the carbon chain growth process. Among all catalysts, Co-doped ZnFe 2 O 4 exhibited the highest surface FeÀ C percentage; therefore, it exhibited the optimal CO 2 conversion, C 2 + selectivity, C 2 -C 4 space-time yield, and olefin/paraffin ratio, which were 42.12 %, 81.26 %, 34.64 %, and 40.25 %, respectively. Furthermore, the introduced Co species can also act as active sites to enhance the activation and dissociation of CO 2 , as confirmed by theoretical adsorption calculations.

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