Influence of pretreatment on the catalytic performance of Ag/CeO2 for formaldehyde removal at low temperature

Degradation of Formaldehyde over MnO2/CeO2 Hollow Spheres: Elucidating the Influence of Carbon Sphere Self-Sacrificing Templates

“…Figure 3 illustrates the temperature dependence of the HCHO conversion at GHSV = 50,000 mL (g cat h) −1 . In MnO 2 /CeO 2 hollow spheres, the conversion of HCHO reaches 70% at 20 °C and reaches full conversion at around 47 °C, which is much lower than its performance of Ag/CeO 2 at 60 °C for T 100% , 18 Ni 0.8 Co 2.2 O 4 at 60 °C for T 100% , 19 and Au/CeO 2 at 60 °C for T 100% . 20 As for MnO 2 /CeO 2 , the conversion of HCHO is 46% at 20 °C, which is much lower than that of MnO 2 /CeO 2 hollow spheres, and reaches full conversion at around 50 °C.…”

Bifunctional zeolites-silver catalyst enabled tandem oxidation of formaldehyde at low temperatures

“…However, upon switching to O 2 at 30 °C, most of the characteristic vibrations of MF disappear, and only bands at 2962, 2846, and 1715 cm −1 for adsorbed MF 31 , 41 , 43 , 44 remain, but their intensities are significantly reduced. In addition, signals of formate species are also apparent at 2950, 2831, 1564, and 1346 cm −1 (red line) 31 , 42 , 43 , 45 – 48 . As temperature increases to 40 °C, signals of adsorbed MF are obviously reduced than that of formate species, indicating that MF is easily converted at low temperatures.…”

Ag-promoted Cr/MnO2 catalyst for catalytic oxidation of low-concentration formaldehyde at room temperature

“…4c, O 1s displays the peaks at the binding energies of 529.8 eV and 531.3 eV, corresponding to the surface lattice oxygen (O I ) and surface adsorbed oxygen (O II ), 42 which play key roles in the complete oxidation and partial oxidation, respectively. 43,44 Table 2 shows that the O II /O I ratio of the Ag/Cr/MnO 2 catalyst is smaller than that of the Cr/MnO 2 catalyst, indicating that the O I of the catalyst increases due to the incorporation of Ag. The surface lattice oxygen species are more abundant in the Ag/Cr/MnO 2 catalyst owing to the presence of Ag on the surface, and the lattice oxygen can combine with the H atom dissociated from formaldehyde, 45 which can reinforce the oxidation capacity for formaldehyde.…”

“…57 As shown in Table 3, the H 2 consumption at peak 1 for the Ag/Cr/MnO 2 catalyst (10.70 mmol g −1 ) is higher than that of the Cr/MnO 2 catalyst (8.95 mmol g −1 ), indicating that the Ag/Cr/MnO 2 catalyst has stronger reducibility at low temperature and a higher initial H 2 consumption rate. 43 Better reducibility is conducive to enhancing the catalytic reaction, and thus the Ag/Cr/MnO 2 catalyst possesses outstanding catalytic property for HCHO. 58,59…”