Effect of Co Doping on Magnetic and CO-SCR Properties of γ-Fe₂O₃

Abstract

Magnetic bayberry-like γ-xCoFe2O3 microspheres catalysts with different mole ratios (Co/Fe = 0, 1, 3, 5, 7, 9%) are synthesized by a solvothermal method followed by calcination. Then, a series of characterizations are carried out using Raman spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), H2 temperature-programmed reduction (TPR), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Also, as the results indicate that with increasing Co doping amount, the microspheres shrink first and then expand, which obviously affect the specific surface area and activity; samples’ catalytic performance is improved by doping an appropriate amount of cobalt, and 5Co–Fe shows the optimum activity with the largest surface area. Moreover, in-situ DRIFTS result shows that the introduction of Co promotes the formation of decomposable monodentate nitrates rather than chelate bidentate nitrates and improve samples’ magnetic properties, which promote more NO adsorbed on catalyst surface to form chelate nitrate species, so that enhanced the activity.

Unraveling the Enhanced Activity and Effect of H2O/O2 on the Low-Temperature NO Reduction by CO over Ag-Modified Porous Co3O4 Nanosheets

“…The adsorbed bands on the Co 3 O 4 surface are shown in Figure S14a. The bands at 1278 and 1315 cm –1 could be assigned to the monobentate nitrates species, and the bands at 1431 and 1486 cm –1 could be ascribed to the monobentate nitrites species. , The bands at 984, 1041, and 1545 (1552) cm –1 could be attributed to be bridged nitrate species. , The bands at 1203 (1186) and 1610 cm –1 could be attributed to chelate bidentate nitrates species . The species at 1448 cm –1 could be assigned to monodentate nitrite species on the 0.02AgCo surface (Figure S14b).…”

“…55,56 The bands at 1203 (1186) and 1610 cm −1 could be attributed to chelate bidentate nitrates species. 57 The species at 1448 cm −1 could be assigned to monodentate nitrite species on the 0.02AgCo surface (Figure S14b). The intensity of the bands in the both spectra decreases with the higher temperature.…”

CuCeOx/VMT powder and monolithic catalyst for CO-selective catalytic reduction of NO with CO

“…However, the vibration modes at 1391 cm À1 and 1209 cm À1 in the range of 1000-1800 cm À1 belong to the different vibration modes of monodentate carbonate v (CQO) and monodentate carbonate v as (CO 3 2À ), and the peak near 1087 cm À1 is the v (C-O) peak coordinated by reduced Ce. [50][51][52] Fig. 8(b) shows the in situ infrared spectrum of the CuCe/ VMT(M) catalyst for NO adsorption.…”

An effective selective catalytic reduction catalyst contains oxygen bridge for NO x reduction based on low concentration of C 3 H 6 at medium‐low temperatures

“…Therefore, the application research of trans-metal catalysts in low temperature CO-SCR system is very limited. 11 In addition, H 2 is also explored as a reductant of SCR de-NO x , especially on silver catalysts. 12 H 2 -SCR system shows good performance at low temperature and can remove the poisonous products.…”