Mn(CeZr)Ox chelation-induced synthesis and its hydrothermal aging characteristics for catalytic abatement of toluene

In this work, Mn(CeZr)O_x was synthesized by using chelation-induced synergistic self-assembly strategy for the combustion of toluene. The physicochemical properties of the synthesized catalysts were characterized by XRD, ICP-MS, SEM, TEM, XPS and N₂ sorption. The Mn(CeZr)O_x catalyst with T₉₀ = 225 °C exhibited improved catalytic performance than the original MnO_x catalyst (T₉₀ = 260 °C) and had significant low-temperature activity. The relationship between catalyst activity and structure was analyzed. By substituting Ce and Zr elements into the hollow microspheres of MnO₂, oxygen vacancies were produced. The main factors affecting the catalytic activity of the catalyst and the reason why it remained high catalytic activity after a long period of hydrothermal treatment were discussed. After hydrothermal aging, the original pore structure of Mn(CeZr)O_x catalyst collapsed and the specific surface area decreased, but the overall crystallinity of the catalyst increased and the content of oxygen species in the lattice increased. The distribution of Mn and oxygen species on the catalyst surface changed significantly after hydrothermal treatment. The appropriate ratio of Mn⁴⁺ to Mn³⁺ and the ratio of lattice oxygen to adsorbed oxygen species are beneficial to the redox reaction cycle.

Reductive C-N Coupling of Nitroarenes: Heterogenization of MoO3 Catalyst by Confinement in Silica

The construction of C-N bonds with nitroaromatics and boronic acids using highly efficient and recyclable catalysts remains a challenge. In this study, nanoporous MoO₃ confined in silica serves as an efficient heterogeneous catalyst for C-N cross-coupling of nitroaromatics with aryl or alkyl boronic acids to deliver N-arylamines and with desirable multiple reusability. Experimental results suggest that silica not only heterogenizes the Mo species in the confined mesoporous microenvironment but also significantly reduces the reaction induction period and regulates the chemical efficiency of the targeted product. The well-shaped MoO₃ @m-SiO₂ catalyst exhibits improved catalytic performance both in yield and turnover number, in contrast with homogeneous Mo catalysts, commercial Pd/C, or MoO₃ nanoparticles. This approach offers a new avenue for the heterogeneous catalytic synthesis of valuable bioactive molecules.

Visible-Light-Responsive Nanofibrous α-Fe2O3 Integrated FeOx Cluster-Templated Siliceous Microsheets for Rapid Catalytic Phenol Removal and Enhanced Antibacterial Activity

Visible-light-driven environmental contaminants control using 2D photocatalytic nanomaterials with an unconfined reaction-diffusion path is advantageous for public health. Here, cost-effective siliceous composite microsheets (FeSiO-MS) combined with two distinct refined α-Fe₂O₃ nanospecies as photofunctional catalysts were constructed via a one-pot synthesis approach. Through precise control of Fe²⁺ precursor addition, specially configured α-Fe₂O₃ nanofibers combined with FeOx cluster-functionalized siliceous microsheets of ∼15 nm gradually evolved from the iron oxide-bearing molecular sieve, endowing a superior light-response characteristic of the formed nanocomposite. The catalytic experiment along with the ESR study demonstrated that the produced FeSiO-MS showed reinforced photo-Fenton reactivity, which was effective for rapid phenol degradation under visible light radiation. Moreover, the phenol removal process was found to be regulated by the specially configured types and concentrations of iron oxides. Notably, the obtained composites exhibited a considerable visible-light-induced bactericidal effect against E. coli. The constructed FeSiO-MS nanocomposites as integrated and eco-friendly photocatalysts exhibit enormous potentials for environmental and hygienic application.

A review of confined-structure catalysts in the catalytic oxidation of VOCs: synthesis, characterization, and applications

This picture depicts the process of the catalytic oxidation of VOCs on confined-structure catalysts, which possess excellent activity and can effectively protect the active phase from aggregation and poisoning.

Record-high capture of volatile benzene and toluene enabled by activator implant-optimized banana peel-derived engineering carbonaceous adsorbents

This work developed a super-high performance of engineering carbonaceous adsorbents from waste banana-peel via an optimized KOH-impregnated approach, which affords outstanding structural property (S_BET = 3746.5 m² g^-1, V_total = 2.50 cm³ g^-1), far outperforming KOH-grinding method-induced counterpart and other known banana peel-derived those. Thereby, this triggers a record-high capture value of volatile organic compounds (VOCs) specific to benzene (27.55 mmol g^-1) and toluene (23.82 mmol g^-1) in the all known results. The structural expression characters were accurately correlated with excellent adsorption efficiency of VOCs by investigating the synthetic factor-controlling comparative samples. Ulteriorly, the adsorption selectivity prediction at different relative humidity was demonstrated through the DIH (difference of the isosteric heats), highlighting the good superiority in selective adsorption of toluene compared to benzene even under humid atmosphere. Our findings provide the possibility for the practical application and fabrication of waste biomass (banana peel)-derived functional biochar adsorbent in the environmental treatment of threatening VOCs pollutants.