Atomically Dispersed Y or La on Birnessite-Type MnO₂ for the Catalytic Decomposition of Low-Concentration Toluene at Room Temperature

Abstract

Room-temperature catalytic decomposition of low-concentration volatile organic compounds (VOCs) in indoor air is an exciting dream to solve their pollution. Herein, two kinds of rare-earth elements (Y and La) were separately doped into birnessitetype MnO 2 nanosheets in the form of single atoms by the hydrothermal method. As-synthesized La/MnO 2 achieved 100% removal of 10 ppm toluene at 40 °C under the gas hourly space velocity of 60 L g −1 h −1 , which was even somewhat better than the single Pt atom-doped MnO 2 . In addition, La/MnO 2 showed the good durability at room temperature for 0.5 ppm toluene removal under the GHSV of 300 L g −1 h −1 and could be effectively regenerated at 105 °C. GC/FID, online-MS and TD-GC/MS analysis demonstrated that only ignorable trace benzene (∼3.4 ppb, < one thousandth of inlet toluene) was generated in the gas phase during catalytic decomposition of 10 ppm toluene at room temperature. This research sheds light on the development of low cost and high activity catalysts for low-concentration VOC oxidation at room temperature.

Thermal-Driven Optimization of the Strong Metal–Support Interaction of a Platinum–Manganese Oxide Octahedral Molecular Sieve to Promote Toluene Oxidation: Effect of the Interface Pt2+–Ov–Mnδ+

“…30,31 The average oxidation state (AOS) of Mn was calculated according to ΔEs (the distance between the binding energy of two peaks) of the Mn 3s spectrum (Figure 3b and Table 2), which further verified the generation of more surface low-valence Mn species on Pt/OMS-2 samples compared with OMS-2. 3,32 It was worth noting that the Mn 2p spectra of Pt/ OMS-2 samples move toward higher binding energies with the increase of treatment temperature, indicating the enhancement of strong metal−support interactions. 15 Three peaks could be observed on O 1s XPS for all samples, which could be assigned to surface lattices oxygen (ca.…”

“…1,2 Toluene, as one of the typical VOCs, is widely used as a solvent in industrial processes such as those of paint, adhesive, rubber, and leather as well as an additive in petroleum and gasoline, which has wide discharge and high toxicity. 3 Therefore, toluene is usually used as a model pollutant in the study of VOC elimination technologies. Among all kinds of control technologies, catalytic oxidation has become the most promising control technology because of its low energy consumption, high treatment efficiency, and absence of secondary pollution.…”

“…Volatile organic compounds (VOCs) not only are harmful to human health but also are important precursors of PM 2.5 and O 3 , causing serious environmental problems. To realize the effective control of VOC emissions, increasingly stringent laws and regulations on VOC emissions are enforced. , Toluene, as one of the typical VOCs, is widely used as a solvent in industrial processes such as those of paint, adhesive, rubber, and leather as well as an additive in petroleum and gasoline, which has wide discharge and high toxicity . Therefore, toluene is usually used as a model pollutant in the study of VOC elimination technologies.…”

“…Therefore, toluene is usually used as a model pollutant in the study of VOC elimination technologies. Among all kinds of control technologies, catalytic oxidation has become the most promising control technology because of its low energy consumption, high treatment efficiency, and absence of secondary pollution. − …”

Noble Metal Single‐Atom Catalysts for the Catalytic Oxidation of Volatile Organic Compounds

“…Accordingly, the formed hydroxyl radicals (⋅OH) were responsible for the efficient degradation of toluene at low temperatures. Other dopants, such as rare‐earth elements (Y and La), were incorporated into birnessite‐type MnO 2 nanosheets as the form of single atoms [25b] . The La 1 /MnO 2 catalyst also showed excellent toluene removal performance at low temperature, and it completely removed 0.5 ppm of toluene at 30 °C and 300000 mL g cat −1 h −1 .…”