MOx/ABO3 is a promising catalyst for the high-efficiency removal of volatile organic compounds. However, this catalyst is limited on practical applications due to its complex synthesis procedure and high cost. In this work, the MnO2/LaMnO3 catalyst was prepared in situ using a facile one-step method for the first time, in which partial La cations were selectively removed from three dimensionally chain-like ordered macroporous (3DOM) LaMnO3 material. After selective removal, the obtained MnO2/LaMnO3 sample expressed an excellent catalytic performance on toluene oxidation. Toluene could be completely oxidized into CO2 and H2O at 290 °C over the MnO2/LaMnO3 catalyst with a toluene/oxygen molar ratio of 1/100 and a space velocity of 120 000 mL/(g h). In addition, the apparent activation energy value of MnO2/LaMnO3 was 57 kJ/mol, which was lower than those of other metal oxides catalysts. According to O2-TPD and XPS results, it is concluded that the high catalytic performance of MnO2/LaMnO3 was mainly associated with the large amount of oxygen species and the excellent lattice oxygen mobility. MnO2/LaMnO3 is a promising catalyst for the practical removal of volatile organic compounds due to its high efficiency, good stability, low cost, and convenient preparation.

No abstract

The high-efficiency catalyst is the key factor of volatile organic compounds (VOCs) catalytic combustion. Herein, hierarchical core–shell Al2O3@Pd-CoAlO (Pd-CoAlO-Al) microspheres have been successfully prepared and used for toluene combustion. The experimental results reveal that the core–shell Pd-CoAlO-Al exhibits outstanding catalytic efficiency due to the homogeneous distribution of Pd-CoAlO nanosheets on Al2O3 supports and the strong interaction between the catalytically active Pd-CoAlO nanosheets and the Al2O3 supports. In particular, the catalytically active PdO contributes to the excellent catalytic efficiency. In addition, the in situ DRIFTS results indicate that the benzoate species are the main intermediate species in toluene combustion.

No abstract

The controlled functionalization of single-walled carbon nanotubes with luminescent sp3-defects has created the potential to employ them as quantum-light sources in the near-infrared. For that, it is crucial to control their spectral diversity. The emission wavelength is determined by the binding configuration of the defects rather than the molecular structure of the attached groups. However, current functionalization methods produce a variety of binding configurations and thus emission wavelengths. We introduce a simple reaction protocol for the creation of only one type of luminescent defect in polymer-sorted (6,5) nanotubes, which is more red-shifted and exhibits longer photoluminescence lifetimes than the commonly obtained binding configurations. We demonstrate single-photon emission at room temperature and expand this functionalization to other polymer-wrapped nanotubes with emission further in the near-infrared. As the selectivity of the reaction with various aniline derivatives depends on the presence of an organic base we propose nucleophilic addition as the reaction mechanism.

Highly efficient, deep desulfurization of model oil containing dibenzothiophene (DBT), benzothiophene (BT), or 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved under mild conditions by using an extraction and catalytic oxidative desulfurization system (ECODS) in which a lanthanide-containing polyoxometalate Na(7)H(2)LnW(10)O(36)⋅32 H(2)O (LnW(10); Ln = Eu, La) acts as catalyst, [bmim]BF(4) (bmim = 1-butyl-3-methylimidazolium) as extractant, and H(2)O(2) as oxidant. Sulfur removal follows the order DBT>4,6-DMDBT>BT at 30 °C. DBT can be completely oxidized to the corresponding sulfone in 25 min under mild conditions, and the LaW(10)/[bmim]BF(4) system could be recycled for ten times with only slight decrease in activity. Thus, LaW(10) in [bmim]BF(4) is one of the most efficient systems for desulfurization using ionic liquids as extractant reported so far.

A B S T R A C TThe polyoxometalate (POM) cluster of [PW 11 O 39 ] 7-(PW 11 ) has been successfully covalent combined with the three dimensionally ordered macroporous graphitic carbon nitride (3DOM g-C 3 N 4 ) through the organic linker strategy. The characterization such as solid-state NMR and XPS results confirm the organosilicon agent of (triethoxysilyl)-propyl isocyanate can act as the linker to covalent combine the PW 11 cluster with 3DOM g-C 3 N 4 . The hybrid catalyst of 3DOM g-C 3 N 4 -PW 11 exhibits efficient catalytic performance (2.4 μmol h −1 ) for lightdriven H 2 O 2 production from H 2 O and O 2 in the absence of organic electron donors. The ESR results suggest that one-electron reduction of O 2 to •OOH is indeed suppressed over 3DOM g-C 3 N 4 -PW 11 . Furthermore, the Koutecky-Levich plot obtained from electrochemical rotating disk electrode (RDE) analysis of oxygen reduction reaction (ORR) for 3DOM g-C 3 N 4 -PW 11 reveals the value of electron transfer during the ORR process is 2.30, indicating the covalent combination can promote the two-electron O 2 reduction. In addition, the recycle experiment results reveal that the heterogeneous 3DOM g-C 3 N 4 -PW 11 is catalytic stable.

No abstract