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Food packages have been detected carrying novel coronavirus in multi-locations since the outbreak of COVID-19, causing major concern in the field of food safety. Metal-based supported materials are widely used for sterilization due to their excellent antibacterial properties as well as low biological resistance. As the principal part of antibacterial materials, the active component, commonly referred to Ag, Cu, Zn, etc., plays the main role in inhibiting and killing pathogenic microorganisms by destroying the structure of cells. As another composition of metal-based antibacterial materials, the carrier could support and disperse the active component, which on one hand, could effectively decrease the usage amount of active component, on the other hand, could be processed into various forms to broaden the application range of antibacterial materials. Different from other metal-based antibacterial reviews, in order to highlight the detailed function of various carriers, we divided the carriers into biocompatible and adsorptable types and discussed their different antibacterial effects. Moreover, a novel substitution antibacterial mechanism was proposed. The coating and shaping techniques of metal-based antibacterial materials as well as their applications in food storage at ambient and low temperatures are also comprehensively summarized. This review aims to provide a theoretical basis and reference for researchers in this field to develop new metal-based antibacterial materials.

With the awakening of environmental awareness, the importance of air quality to human health and the proper functioning of social mechanisms is becoming increasingly prominent. The low cost and high efficiency of catalytic technique makes it a natural choice for achieving deep air purification. Stainless steel alloys have demonstrated their full potential for application in a variety of catalytic fields. The diversity of 3D networks or fibrous structures increases the turbulence within the heterogeneous catalysis, balance the temperature distribution in the reaction bed and, in combination with a highly thermally conductive skeleton, avoid agglomeration and deactivation of the active components; corrosion resistance and thermal stability are adapted to highly endothermic/exothermic or corrosive reaction environments; oxide layers formed by bulk transition metals activated by thermal treatment or etching can significantly alter the physico-chemical properties between the substrate and active species, further improving the stability of stainless steel catalysts; suitable electronic conductivity can be applied to the electrothermal catalysis, which is expected to provide guidance for the reduction of intermittent emission exhausts and the storage of renewable energy. The current applications of stainless steel as catalyst or support in the air purification have covered soot particle capture and combustion, catalytic oxidation of VOCs, SCR, and air sterilization. This paper summarizes several preparation methods and presents the relationships between the preparation process and the activity, and reviews its application and the current status of research in atmospheric environmental management, proposing the advantages and challenges of the stainless steel-based catalysts.

Mn-Si-MEL zeolite was developed as a bi-functional adsorption-catalytic oxidation material for volatile organic compounds (VOCs) elimination due to its good hydrophobicity & good organophileproperty brought by the substitution of Mn for Al in zeolite and the superior catalytic oxidation property endowed by the existence of Mn species. Various Mn-Si-MEL samples were obtained by introducing Mn to MEL crystallization system via different ways. It was found the incorporated Mn ways have a significant effect on the behavior of Mn being involved in the crystallization of MEL and finally influenced the distribution of Mn in zeolite as well the physicochemical properties of product zeolite. The seeding method (Mn-S2(Seed)) is favorable for the good incorporation and uniform distribution of Mn in zeolite while both recrystallization method (Mn-S2(RC)) and direct synthesis method (Mn-S2(DH)) are favorable for obtaining more reducible Mn species and surface adsorbed oxygen species. The Mn amount incorporated into zeolite follows Mn-S2(RC) (1.96 wt%) > Mn-S2(Seed) (1.07 wt%) ≈ Mn-S2(DH) (0.97 wt%), the adsorption capacity of various samples follows Mn-S2(Seed) (83.3 μmol/g) ≈ Mn-S2(RC) (82.1 μmol/g) > Mn-S2(DH) (76.1 μmol/g), while the catalytic oxidation ability of three samples follows Mn-S2(RC) ≈ Mn-S2(DH) > Mn-S2(Seed). Furthermore, Mn-S2(RC) which exhibits both superior adsorption capacity and catalytic oxidation ability shows good hydrophobicity and superior recyclability, demonstrating its great potential to be applied in the VOCs elimination by an enrichment-degradation route.

NH3-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method. Due to its strong oxidation performance, Sn-MnOx was prone to side reactions between NO, NH3 and O2, resulting in the generation of more NO2 and N2O, here most of N2O was driven from the non-selective oxidation of NH3, while a small part generated from the side reaction between NH3 and NO2. Co or Ni doping into Sn-MnOx as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N2O. The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO2 to provide more surface adsorbed oxygen, active sites of Mn3+ and Mn4+, high-content Sn4+ and plentiful Lewis-acidity for more active intermediates, which significantly broadened the activity window of Sn-MnOx, improved the N2 selectivity by inhibiting N2O formation, and also contributed to an acceptable resistances to water and sulfur. At low reaction temperatures, the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal (E-R) routs via the reactions of adsorbed l -NHx (x = 3, 2, 1) and B-NH4+ with the gaseous NO to generate N2 but also N2O by-products. Except for the above basic E-R reactions, as increasing the reaction temperature, the main adsorbed NOx-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed l -NHx species over Co/Ni modified Mn-SnO2 catalyst.

This review summarizes the synthesis, applications for the NH3-SCR and methods for strengthening the water resistance and thermal stability of MOF catalysts.

A new method for delaying or avoiding catalyst poisoning in COS catalytic hydrolysis was found by using one of the existing gas components in blast furnace flue gas: CO. In this work, wood-based ac...

Achieving high catalytic performance with lower possible cost and higher energetic efficiency is critical for catalytic oxidation of volatile organic compounds (VOCs). However, traditional thermocatalysts generally undergo low catalytic activity and fewer active sites. Herein, this paper synthesizes nearly all-surface-atomic, ultrathin two-dimensional (2D) Co3O4 nanosheets to address these problems through offering a numerous active sites and high electron mobility. The 2D Co3O4 nanosheets (1.70 nm) exhibit catalyzation to the total oxidation of n-hexanal at the lower temperature of T90% = 202 °C, and at the space velocity of 5.0 × 104 h−1. It is over 1.2 and 6 times higher catalytic activity than that of 2D CoO nanosheets (1.71 nm) and bulk Co3O4 counterpart, respectively. Transient absorption spectroscopy analysis shows that the oxygen vacancy defect traps electrons, thereby preventing the recombination with holes, increasing the lifetime of τ1 electrons, and making electron-holes reach a nondynamic equilibrium. The longer the electron lifetime is, the easier the oxygen vacancy defects capture electrons. Furthermore, the defects combine with oxygen to form active oxygen components. Compared with the lattice oxygen involved in the reaction of bulk Co3O4, the nanosheets change the catalytic reaction path, which effectively reduces the activation energy barrier from 34.07 to 27.15 kJ/mol. The changed surface disorder, the numerous coordinatively-unsaturated Co atoms and the high ratio of Oads/Olat on the surface of 2D Co3O4 nanosheets are responsible for the catalytic performance.

Background: Pharmacogenetics study was added into 2 bioequivalence trials of aripiprazole. The correlation between CYP2D6 polymorphisms and aripiprazole pharmacokinetics (PK) was analyzed. Materials & methods: A total of 140 subjects were included. A total of 26 CYP2D6 gene alleles were detected. The plasma concentration of aripiprazole was measured by liquid chromatography-tandem mass spectrometry. SPSS Statistics 21 was used to analyze the correlation between CYP2D6 polymorphisms and aripiprazole PK parameters. Results: All of the four PK parameters were significantly influenced by CYP2D6 rs1058164 and rs28371699. t1/2 and area under the concentration-time curve exhibited significant difference between CYP2D6 extensive metabolizers and intermediate metabolizers. Conclusion: Aripiprazole PK was greatly influenced by CYP2D6. Attention should be paid to the possible dose adjustment for CYP2D6 intermediate metabolizer population when the drug is used in Chinese patients.

Cu-Co multiple-oxides modified on HNO3-pretreated activated coke (ACN) were optimized for the simultaneous removal of gaseous CO and elemental mercury (Hg0) at low temperature (

Over the years, the combined Non-thermal Plasma (NTP) denitrification process which is used for decomposition of NOx has have become an application technology with great potential. And the formation of byproducts, such as N2O and O3, which is an important factor that interfere with NO removal efficiency, has a high research value. In present study, HZSM-5 molecular sieve was selected as the packed material in dielectric barrier discharge reactor to investigate the effect of reaction conditions, such as with/without packed bed, discharge power, inner electrode diameter, electrode shape and operation time, on formation and conversion characteristics of byproducts (N2O and O3). Results showed that the presence of HZSM-5 pellets in discharge zone increases the discharge power, NO removal efficiency and the concentration of the byproducts in the outlet. The optimization of electrode diameter and the utilization of screw thread electrode increased the NO removal efficiency and the yield of N2O and O3. The pellets temperature increases with the operation time and the enhancement of input energy, which has different effects on O3 and N2O. These results provide some new methods for improving the NTP-assisted catalytic denitrification process.

Introducing oxygen vacancies into metal oxides is a promising strategy to promote their catalytic activity, which has been extensively studied in heterogeneous catalysis. Herein, transition metal (...

In this paper, Al atomic-scale doping has been achieved by using NiAl hydrotalcite-like compounds (HTLCs) as precursors method. Regulatory effect of Al doping in NiO for carbonyl sulfide (COS) removal was studied. The samples were systematically characterized by XRD, SEM, N2 adsorption/desorption, FTIR, CO2-TPD, XPS, XAFS and In-situ DRIFTS. The results showed that the activity series for removal of COS decrease in the following sequence: Ni3Al-HTO > Ni5Al-HTO > Ni1Al-HTO. The enhanced activity after Al atomic-scale doping is attributed to the abundant surface basic sites as evidenced by results of CO2-TPD. XPS and XAFS provide evidence for the reduction of Ni2+ by Al doping in NiO, which suggest large amounts of O-vacancies present on Ni3Al-HTO. This work is useful to explore feasible routes to improve the performance of desulfurization material for the feed gas purification.

Zinc species were fixed in the silicalite-2 zeolite by a crystallisation process control method. By controlling the introduction time of Zn during the crystallisation process, the distribution of Zn species in zeolite crystals can be facilely adjusted. Particularly, as Zn species were introduced after the completion of nucleation or crystal growth, crystals with structure of silica-core and Zn-silica shell will be formed. The ratio of shell to core thickness can be easily varied by adjusting the Zn feeding time as well as controlling the recrystallisation period.

BACKGROUND: A novel semi‐dry method called SDA (spray drying absorption) for the simultaneous removal of mercury (Hg⁰) and sulfur dioxide (SO₂) have been proposed in this article, in which Hg⁰ was initially oxidized by gaseous oxidant (O₃) and liquid oxidant (K₂S₂O₈, H₂O₂, and NaClO₂), after which SO₂ and Hg²⁺ were absorbed by Ca(OH)₂. RESULTS: The effects on different process conditions and additives on Hg⁰ removal were explored at first, and the results indicated that the Hg removal efficiency could be improved by oxidizing or extending the residence time of the liquid phase reaction. When SO₂ and Hg coexist in the atmosphere, additives including oxidants or composite additives were added into the mixed system, and the results indicated that the best removal efficiency of SO₂ and Hg was about 99.5% and 51% respectively. CONCLUSION: Since SO₂ has good water solubility, it would affect the oxidation of Hg and the removal of Hg. When there was nitric oxide (NO) in the atmosphere, a new stable product was generated which contributed to the removal of Hg, and the removal efficiency of SO₂ and Hg was about 99.5% and 57% respectively. © 2020 Society of Chemical Industry

Catalytic oxidation of toluene over noble metal catalysts is a representative reaction for elimination of volatile organic compounds (VOCs). However, to fully understand the activation of molecular oxygen and the role of active oxygen species generated in this reaction is still a challenging target. Herein, MgO nanosheets and single-atom Pt loaded MgO (Pt SA/MgO) nanosheets were synthesized and used as catalysts in toluene oxidation. The activation process of molecular oxygen and oxidation performance on the two catalysts were contrastively investigated. The Pt SA/MgO exhibited significantly enhanced catalytic activity compared to MgO. The oxygen vacancies can be easily generated on the Pt SA/MgO surface, which facilitate the activation of molecular oxygen and the formation of active oxygen species. Based on the experimental data and theoretical calculations, an active oxygen species promoted oxidation mechanism for toluene was proposed. In the presence of H2O, the molecular oxygen is more favorable to be dissociated to generate •OH on the oxygen vacancies of the Pt SA/MgO surface, which is the dominant active oxygen species. We anticipate that this work may shed light on further investigation of the oxidation mechanism of toluene and other VOCs over noble metal catalysts.

Mn-Ni oxides with different compositions were prepared using standard co-precipitation (CP) and urea hydrolysis-precipitation (UH) methods and optimized for the selective catalytic reduction of nitrogen oxides (NOx) by NH3 at low temperature. Mn(2)Ni(1)Ox-CP and Mn(2)Ni(1)Ox-UH (with Mn:Ni molar ratio of 2:1) catalysts showed almost identical selective catalytic reduction (SCR) catalytic activity, with about 96% NOx conversion at 75°C and ~99% in the temperature range from 100 to 250°C. X-ray diffraction (XRD) results showed that Mn(2)Ni(1)Ox-CP and Mn(2)Ni(1)Ox-UH catalysts crystallized in the form of Mn2NiO4 and MnO2-Mn2NiO4 spinel, respectively. The latter gave relatively good selectivity to N2, which might be due to the presence of the MnO2 phase and high metal-O binding energy, resulting in low dehydrogenation ability. According to the results of various characterization methods, it was found that a high density of surface chemisorbed oxygen species and efficient electron transfer between Mn and Ni in the crystal structure of Mn2NiO4 spinel played important roles in the high-efficiency SCR activity of these catalysts. Mn(2)Ni(1)Ox catalysts presented good resistance to H2O or/and SO2 with stable activity, which benefited from the Mn2NiO4 spinel structure and Eley-Rideal mechanism, with only slight effects from SO2.

A large number of studies had shown that the morphology of the sample had a significant effect on the microwave absorption properties and catalytic activity of the sample. Manganese dioxide with different morphologies was synthesized by hydrothermal method through different precursors. The effects of sample morphology and microwave absorption properties on the catalytic activity of the sample in conventional thermal and microwave fields were studied. The results indicated that compared with the conventional thermal field, the catalytic activity of the samples in microwave field were obviously improved, and the activation energy of the reaction were decreased. Compared with the conventional thermal field, the conversion of toluene in microwave thermal field of MnO2(Ac), MnO2(S) and MnO2(N) increased by 59%, 42% and 12%, and the mineralization rate increased by 36%,11% and 2%, respectively, when the catalytic temperature was 150 °C. Compared with the traditional thermal field, the activation energy of the sample MnO2(Ac) in the microwave field was reduced by 88.3 KJ. A series of characterization results showed that the sample MnO2(Ac) had good catalytic activity in the microwave field was due to: MnO2(Ac) had proper microwave absorption properties, large amount of surface functional groups, large specific surface area and rich pore structure. The analysis results of electromagnetic parameters showed that: the reason that the sample MnO2(Ac) had good microwave absorption performance was that the MnO2(Ac) had proper impedance matching, high attenuation constant and Debye dipole relaxation effect.

Novel Mn–Ni spinel nanosheets were investigated for the NH3-SCR of NO at low temperature by urea-hydrolysis (UH) and urea-hydrolysis hydrothermal-synthesis (UHHS), and compared with co-precipitation hydrothermal synthesis (CPHS) and co-precipitation (CP) methods. The optimum molar ratio of Mn/Ni (2 : 1) and urea/(Mn + Ni) (3 : 1) were determined, as also were the suitable hydrothermal temperature (130 °C for 24 h) and further calcination (450 °C for 6 h). An Mn(2)Ni(1)Ox-UHHS catalyst produced a purer spinel-structured NiMn2O4 nanosheet than Mn(2)Ni(1)Ox-UH, both of which showed highly efficient SCR activity (>98% NOx conversion at 100–250 °C) and N2 selectivity (>95% at 85% at

A series of MnCoOx flower-like hollow microspheres with various molecular proportions of reactant were prepared through simple solvothermal method for the ammonia selective catalytic reduction (SCR) at low temperatures. The as-prepared samples have been applied by various characterization techniques to explore the formation process of the morphology and physicochemical properties. The Mn(1)Co(1)Ox presented the optimal intrinsic catalytic performance (95% NOx conversion at 75 °C), favorable thermal stability, and strong SO2 resistance. The excellent properties mainly related to its higher specific surface area and abundant active sites originated from hollow microsphere special structure consists of abundant nanosheets, robust redox properties beneficial for the strong interaction between the manganese and cobalt, larger number of acidic sites and stronger acid strength, etc., which collaboratively dominate its catalytic properties of NH3-SCR at low temperatures.