“…All the catalysts had diffraction peaks at 35.5, 38.9, 48.8, and 61.5°, which were assigned to the CuO phase. 14,26,27 Moreover, the peaks (2θ = 6.8, 15.5, 18.5, 20.2, 23.4, 26.8, and 30.5°) belonged to the structure of zeolite X were observed on Cu(N)X and Cu(N)X−S catalysts, 25,28,29 and the peak intensity of the Cu(N)X catalyst was higher, while there were only two peaks appeared on Cu(S)X and Cu(C)X catalysts, indicating that the structure of zeolite X in Cu(S)X and Cu(C)X catalysts might be destroyed during the ion-exchanged process, but the Cu(N)X catalyst still remained the zeolite X structure, which might be one of the reasons for the excellent SCR activity performance for the Cu(N)X catalyst. The microtopography of Cu(S)X, Cu(N)X, Cu(C)X, and Cu(N)X−S catalysts is described in Figure 3.…”