Nitrogen oxides (NOx) in fluid catalytic cracking (FCC) units, which are major atmospheric pollutants, are hazardous to the human body and environment. In this work, the CuO–CeO2catalyst prepared by the co-precipitation method (CuCe–CPM) is applied in the CO-selective catalytic reduction (CO-SCR) reaction. NO and CO can be completely converted to exhaust gas, CO2and N2, in the temperature range of 600–700 °C. Subsequently, we propose a new method of application of the generated exhaust gas, where the exhaust gas is employed to enhance shale gas recovery and achieve sequestration within the shale reservoir. A series of comparisons of CH4displacement efficiency and sequestration capacity of reaction gas (CO + NO) and generated waste gas (CO2+ N2) in kerogen slit nanopores were performed. It is found that the displacement efficiency of CO2+ N2as the driving gas is higher than that of CO + NO within the formation depth from 0.33 to 3 km. The displacement efficiency of CO2+ N2reached 70 and 76% when the reservoir depths reached 1 and 3 km, respectively, with a pressure increase of 30 MPa and a temperature increase of 54.6 °C during this period. The displacement process is dominated by the interaction between kerogen and driving gas. The sequestration capacity of CO2+ N2is slightly weaker than that of CO + NO, but direct CO2+ N2sequestration has the advantages of being harmless and less corrosive and with fewer operational safety hazards. The proposed scheme may provide a feasible guide to the NOxtreatment process and the application of the generated exhaust gas from FCC units.