Co3O4 supported on ZSM-5 (Co3O4/ZSM-5) catalysts were prepared by impregnation (IM), deposition precipitation (DP), and hydrothermal (HT) methods. Their catalytic performances for the total oxidation of propane were tested, and their physicochemical properties were investigated by low-temperature N2 adsorption, XRD, FT-IR absorption spectroscopy, XPS, H2-TPR, TEM, and CO chemisorption. The results show that the catalytic activity of Co3O4/ZSM-5 for propane oxidation is higher than that of 1.5 wt % Pd/ZSM-5, and the preparation methods remarkably affect the catalytic activity of Co3O4/ZSM-5. Among four Co3O4/ZSM-5 catalysts prepared by different methods, the catalyst prepared by the HT method possesses the highest catalytic activity for propane oxidation, and their catalytic activities are varied in the order of HT > DP > IM. For the Co3O4/ZSM-5 (DP) catalysts, the precipitant has an evident influence on their catalytic activities. For instance, the DP catalyst prepared with ammonium bicarbonate precipitant has a higher catalytic activity than the catalyst prepared with sodium hydroxide precipitant. The excellent catalytic activity of Co3O4/ZSM-5 (HT) may be attributed to the better reducibility of Co3+, higher Co3+ content, higher surface concentration, and fast migration of the lattice oxygen of Co3O4 on this catalyst. Furthermore, the Co3O4/ZSM-5 catalyst prepared by the HT method exhibits a high stability after being used at 500 °C for 40 h.

Tungsten‐modified 1.5 wt. % platinum supported on ZSM‐5 catalysts were prepared, and their performances for the total oxidation of propane and the role of tungsten in the catalysts were investigated. The results show that the addition of tungsten can improve the catalytic activity of Pt/ZSM‐5. When the tungsten loading is 5 wt. %, the Pt‐5W/ZSM‐5 catalyst demonstrates excellent catalytic activity and its turnover frequency is more than 1 order of magnitude higher than that of the Pt/ZSM‐5 catalyst. Analyses of the surface properties of catalysts reveal that metallic platinum is scarcely found on the Pt/ZSM‐5 catalyst without tungsten; the addition of tungsten can modify the nature of platinum species, which results in the presence of metallic platinum in the Pt‐W/ZSM‐5 catalyst. The amount of metallic platinum in the Pt‐W/ZSM‐5 catalyst depends on the tungsten loading and can correlate directly with its catalytic activity. Therefore, the oxidation resistance of platinum in the Pt‐W/ZSM‐5 catalyst seems to be responsible for the improved catalytic activity in propane oxidation. In addition, the Pt‐5W/ZSM‐5 catalyst demonstrates higher stability; no deactivation of the Pt‐W/ZSM‐5 catalyst is observed after the online test for 50 h, with the temperature alternating between 200 °C for 10 h and 500 °C for 10 h. Therefore, the Pt‐5W/ZSM‐5 catalyst demonstrates better catalytic activity for propane oxidation than the Pt/ZSM‐5 catalyst after online aging at 700 °C for 30 h.

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In this study, the de-NOx performance of Cu-based zeolite catalysts supported on topological structure (SSZ-13, BEA, ZSM-5) and loaded with different doses of copper (from 2 to 6 wt.%) was investigated. The preparation of copper-based catalysts adopted the incipient wetness impregnation method. To analyze the physicochemical properties of the catalysts, advanced techniques like BET, XRD, NH3-TPD, H2-TPR, and DRS UV-Vis were used. The performance tests suggested the 4Cu/SSZ-13 catalyst exhibited higher low-temperature activity and wider temperature window. Furthermore, compared with Mn-Cu/SSZ-13, the Ce-Cu/SSZ-13 catalysts exhibited better de-NOx performance.

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