Ultralow Loading of Silver Nanoparticles on Mn₂O₃ Nanowires Derived with Molten Salts: A High-Efficiency Catalyst for the Oxidative Removal of Toluene

Abstract

Using a mixture of NaNO3 and NaF as molten salt and MnSO4 and AgNO3 as metal precursors, 0.13 wt % Ag/Mn2O3 nanowires (0.13Ag/Mn2O3-ms) were fabricated after calcination at 420 °C for 2 h. Compared to the counterparts derived via the impregnation and poly(vinyl alcohol)-protected reduction routes as well as the bulk Mn2O3-supported silver catalyst, 0.13Ag/Mn2O3-ms exhibited a much higher catalytic activity for toluene oxidation. At a toluene/oxygen molar ratio of 1/400 and a space velocity of 40,000 mL/(g h), toluene could be completely oxidized into CO2 and H2O at 220 °C over the 0.13Ag/Mn2O3-ms catalyst. Furthermore, the toluene consumption rate per gram of noble metal over 0.13Ag/Mn2O3-ms was dozens of times as high as that over the supported Au or AuPd alloy catalysts reported in our previous works. It is concluded that the excellent catalytic activity of 0.13Ag/Mn2O3-ms was associated with its high dispersion of silver nanoparticles on the surface of Mn2O3 nanowires and good low-temperature reducibility. Due to high efficiency, good stability, low cost, and convenient preparation, 0.13Ag/Mn2O3-ms is a promising catalyst for the practical removal of volatile organic compounds.

Self-Templating Synthesis of 3D Hierarchical NiCo2O4@NiO Nanocage from Hydrotalcites for Toluene Oxidation

“…Volatile organic compounds (VOCs), collectively composed by a lot of hazardous organics, not only directly affect environment and human health, but also cause photochemical ozone/smog pollution as precursors [1]. Benzene, toluene, ethylbenzene, and xylenes (BTEX), which are environmentally detrimental VOCs but indispensable chemicals, can corrode skin and irritate the respiratory system, and even affect the nervous system with prolonged exposures [2].…”

Mn Ion substituted CeO2Nano spheres for Low Temperature CO Oxidation: The Promoting Effect of Mn Ions

“…In H 2 ‐TPR profile for pure CeO 2 , there is only a single peak centered at ∼ 480 °C due to the reduction of surface oxygen. Generally, the peaks for the reduction of Mn 4+ → Mn 3+ and Mn 3+ →Mn 2+ are observed at ∼ 385 °C and 505 °C in manganese oxides respectively . But, Mn ion substituted CeO 2 showed the reduction peaks at lower temperature than that obtained from MnO 2 , Mn 3 O 4 and Mn 2 O 3 .…”

Carbon Nanotubes–MnOx Nanocomposite as Support for Iron‐Based Catalysts for the Fischer–Tropsch Synthesis of Liquid Fuels

“…MnO 2 is the dominant crystal phase (JCPDS card no. 80‐1098) in CNTs‐K‐110 and CNTs‐KU‐110; however, the crystal phase of the Mn 2 O 3 phase (JCPDS card no.41‐1442) is observed in the other samples synthesized at 190 °C . A valence shift from MnO 2 (Mn 4+ ) to Mn 2 O 3 (Mn 3+ ) with increasing hydrothermal temperature is of concern, and higher temperature could lead to the reduction of MnO 2 (Mn 4+ ) to Mn 2 O 3 (Mn 3+ ).…”

“…[11] MnO 2 is the dominant crystal phase (JCPDS card no.8 0-1098) in CNTs-K-110 and CNTs-KU-110; [12] however, the crystal phase of the Mn 2 O 3 phase (JCPDS card no.41-1442) is observed in the other samples synthesized at 190 8C. [13] Av alence shift from MnO 2 (Mn 4 + ) to Mn 2 O 3 (Mn 3 + )w ith increasing hydrothermal temperature is of concern, and higher temperature could lead to the re-ductiono fM nO 2 (Mn 4 + )t oM n 2 O 3 (Mn 3 + ). As mentioned above,t he MnO x incorporatedi nto the CNTs framework follows the redox reaction between the aqueouss olution of KMnO 4 and the CNTs surface.…”