A state-of-the-art review on indoor air pollution and strategies for indoor air pollution control.

Engineering MnO2 with rich surface active oxygen species is critical to effectively eliminate formaldehyde (HCHO) under mild conditions. Herein, we introduced a facile redox method to fabricate a series of δ-MnO2 samples by varying the concentration of K+, which efficiently modulated the layer size, morphology, crystallinity, redox properties, and thus the surface active oxygen species of the obtained δ-MnO2. The medium potassium concentration led to the optimized Mn O bond strength, the abundant surface active oxygen species, and the complete conversion of ca. 22 ppm HCHO at 30 °C under a weight hourly space velocity (WHSV) of 200,000 mL/(gcat h). Surface adsorbed oxygen species (e.g., O2− and O−) and surface hydroxyl groups, were suggested to oxidize HCHO into intermediates (i.e., DOM, formate, and carbonate species). Water was critical for further transforming the intermediates into CO2. A Langmuir-Hinshelwood (LH) mechanism was proposed involving in the whole oxidation process.

Potassium-modulated δ-MnO2 as robust catalysts for formaldehyde oxidation at room temperature

Black TiO2: A review of its properties and conflicting trends

Although manganese oxide (MnO2) exhibits excellent activity in various oxidation reactions, especially for volatile organic compound oxidation, the origin of the catalytic activity remains ambiguou...

Investigation into the Catalytic Roles of Various Oxygen Species over Different Crystal Phases of MnO2 for C6H6 and HCHO Oxidation

Catalytic oxidation of formaldehyde (HCHO) at room temperature is one of the most viable approaches to indoor HCHO pollution abatement. Herein, three-dimensional (3D) carbon foam decorated with Pt/MnO2 nanosheets (Pt/MnO2-CF) was in-situ synthesized for room-temperature catalytic oxidation of HCHO. The 3D Pt/MnO2-CF with a low platinum content of 0.3 wt% exhibited excellent catalytic activity because of its hierarchically porous structure facilitating the diffusion of reactant molecules. Moreover, an abundance of active oxygen species resulting from oxygen vacancies are favorable for HCHO oxidation. In addition, the carbon foam substrate exhibited a very good HCHO adsorption capability, which helps achieve prompt reduction in HCHO concentration in the gas-phase and subsequent complete oxidation of adsorbed HCHO. The combination of adsorption and oxidation was more favorable for oxidative decomposition of HCHO. This work demonstrates that such 3D nanocomposites with low noble metal loading have promising application for indoor HCHO removal and air purification.

Biyuan Liu

Papers

Catalytic ozonation of VOCs at low temperature: A comprehensive review

Reduced TiO2 with tunable oxygen vacancies for catalytic oxidation of formaldehyde at room temperature

Effect of K+ ions on efficient room-temperature degradation of formaldehyde over MnO2 catalysts

Efficient photocatalytic oxidation of gaseous toluene over F-doped TiO2 in a wet scrubbing process

Efficient MnOx/SiO2@AC catalyst for ozone-catalytic oxidation of gaseous benzene at ambient temperature