Component synergistic catalysis of Ce-Sn-W-Ba-Ox/TiO2 in selective catalytic reduction of NO with ammonia

Discovering Surface Structure and the Mechanism of Graphene Oxide-Triggered CeO2–WO3/TiO2 Catalysts for NO Abatement with NH3

“…Nitrogen oxides (NO x ) emitted from diesel engines are major air pollutants, which result in ozone depletion, photochemical smog, and acid rain, causing adverse effects on anthropic and ecological environment health. , To prevent and control tailpipe pollutions of NO x , governments have formulated policies and regulations, such as China VI or Euro VI, to strictly limit the emissions of diesel vehicles. Selective catalytic reduction of NO by NH 3 (NH 3 -SCR) has been proved to be a state-of-art technology for NO x removal. , Much effort has been made to synthesize efficient NH 3 -SCR catalysts, such as Cu-exchanged SSZ-13 or SSZ-39 and various metal oxides catalysts. , Although V 2 O 5 /TiO 2 promoted by WO 3 or MoO 3 has been widely commercialized in NH 3 -SCR, there are still critical drawbacks of a narrow operating temperature window, the toxicity of V 2 O 5 , and low N 2 selectivity. , For these reasons, the development of a vanadium-free and environment-friendly SCR catalyst with excellent efficiency at low temperatures is highly desirable.…”

Rationally Tailored Redox Properties of a Mesoporous Mn–Fe Spinel Nanostructure for Boosting Low-Temperature Selective Catalytic Reduction of NOx with NH3

“…Previous studies have confirmed that the three H 2 consumption peaks (300, 550, and 650 °C) of γ-Fe 2 O 3 are ascribed to the sequential stepwise reduction of Fe 2 O 3 → Fe 3 O 4 → FeO → Fe. , Some reports also illustrated that the two reduction peaks of MnO x (315 and 460 °C) were attributed to the two-step reduction of MnO 2 → Mn 2 O 3 /Mn 3 O 4 → MnO. , The Mn 0.5 Fe 2.5 O 4 -P catalyst also exhibits three reduction peaks but all shift to a low temperature with about 50 °C. Besides, the initial reduction temperature of Mn 0.5 Fe 2.5 O 4 -S is 100 °C higher than that of Mn 0.5 Fe 2.5 O 4 -P, illustrating the lower redox properties of Mn 0.5 Fe 2.5 O 4 -S. ,, It is noteworthy that the α area (Figure S5) of the Mn 0.5 Fe 2.5 O 4 -P catalyst is almost twice that of the Mn 0.5 Fe 2.5 O 4 -S sample, which plays the most significant role in the redox properties of catalysts. , The total amount of H 2 consumption (18.6 mmol H 2 ·g –1 ) of Mn 0.5 Fe 2.5 O 4 -P is obviously higher than that (17.3 mmol H 2 ·g –1 ) of Mn 0.5 Fe 2.5 O 4 -S (Table S2), demonstrating the stronger redox ability of Mn 0.5 Fe 2.5 O 4 -P once again. Compared with the particle catalyst, the higher reduction temperature of Mn 0.5 Fe 2.5 O 4 -S is likely to result from the special mesoporous nanostructure.…”

“…Besides, the initial reduction temperature of Mn 0.5 Fe 2.5 O 4 -S is 100 °C higher than that of Mn 0.5 Fe 2.5 O 4 -P, illustrating the lower redox properties of Mn 0.5 Fe 2.5 O 4 -S. 22,31,43 It is noteworthy that the α area (Figure S5) of the Mn 0.5 Fe 2.5 O 4 -P catalyst is almost twice that of the Mn 0.5 Fe 2.5 O 4 -S sample, which plays the most significant role in the redox properties of catalysts. 44,45 The total amount of H 2 consumption (18.6 mmol H 2 •g −1 ) of Mn 0.5 Fe 2.5 O 4 -P is obviously higher than that (17.3 mmol H 2 •g −1 ) of Mn 0.5 Fe 2.5 O 4 -S (Table S2), demonstrating the stronger redox ability of Mn 0.5 Fe 2.5 O 4 -P once again. Compared with the particle catalyst, the higher reduction temperature of Mn 0.5 Fe 2.5 O 4 -S is likely to result from the special mesoporous nanostructure.…”

Selective catalytic reduction of NO over W–Zr-Ox/TiO2: performance study of hierarchical pore structure

“…9(b), the O 1s could be divided into chemisorbed oxygen (O a , 531.2 eV) and lattice oxygen (O b , 529.6 eV). [42][43][44] Similar to the change of the Ti 2p, the addition of citric acid monohydrate caused the shi of the O 1s. Compared with WZ/ T, the chemisorbed oxygen concentrations of 5C-WZ/T, 10C-WZ/ T and 15C-WZ/T decreased obviously.…”