Fig. 5: Identification of the deactivated Cu species. | Nature Catalysis

Fig. 5: Identification of the deactivated Cu species.

From: Tailoring the active sites in Cu-SSZ-13 as a catalyst for the selective catalytic reduction of NH3 to minimize HCHO and HCN emissions

Fig. 5

a,c, In situ XANES measurements at the middle position of the catalyst bed under model gas conditions of 25 ppm HCHO and 10% O2 in He (a) and 100 ppm HCN and 10% O2 in He (c) for Cu-SSZ-13 (7/1.3) (black lines) and Cu-SSZ-13 (14/1.3) (red lines) at 300 °C. Corresponding FDMNES-calculated (calc.) XANES spectra are also depicted. b, XES spectra of Cu-SSZ-13 (7/1.3) during steady-state SCR conditions in the presence (red line) and absence (black line) of formaldehyde at 300 °C. The gas composition was 350 ppm NO, 350 ppm NH3, 0–100 ppm HCHO, 0.5% H2O and 10% O2 in He. d, FDMNES-calculated XES spectra based on the the structures shown in a and c. e, Predicted structures of formate, cyanide and possible Cu–CN/NH3 species determined by DFT calculations (green, grey, red, yellow, cyan, dark blue and white represent Al, C, O, Si, Cu, N and H, respectively).

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