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The selective catalytic reduction (SCR) of NOxwith ammonia is an effective method to remove NOxfrom stationary and mobile sources. Cerium oxides (CeOx) have been studied extensively as low-temperature SCR catalysts since they manifest prominent oxygen storage capacity in catalysis. This paper reviews the recent progress on the Ce-based catalysts for low-temperature SCR de-NOxwith NH3, including three categories, single CeOx, Ce-based multimetal oxide, and Ce-based multimetal oxides with support. In the section on single CeOx, the reasons for the significant catalytic activity and the function of CeOxin the catalytic reactions are systematically reviewed. For multimetal oxide catalysts, the various roles played by the components of catalysts are summarized from several aspects. In the introduction of supported metal oxide catalysts, according to the type of support, the function of each support in the reaction is analyzed methodically. Additionally, we investigated the reaction mechanism of low-temperature SCR of NOx, including Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms. Finally, the development outlook and direction of the application of cerium oxide-based catalysts in the field of low-temperature SCR of NOxis prospected.

In this study, novel Schottky-junction photocatalysts Bi-metal-deposited g-C3N4were constructed via a one-step solvothermal process for photocatalytic CO2reduction under simulated irradiation. The photocatalytic performance illustrated that the nanohybrid catalysts have extreme activity and excellent stability. The maximum CO yield of 3.78 μmol h–1g–1was reached on the BiCN-0.6 hybrid, which was about 3 times as much as that of pure g-C3N4. The phase, microstructure, and optical and photoelectrochemical properties were demonstrated by related characterization methods. The improvement mechanism could be ascribed to the enhanced photon absorption capacity and the decreased recombination rate of photoinduced carriers arising from the Schottky barrier in the system. This work may provide a meaningful approach to enhance the photocatalytic activity through a simple and green strategy.