In this work, the catalytic pyrolysis of a corn stalk/high-density polyethylene composite for aromatics production over activated carbon in a fixed-bed reactor was investigated. The effects of the ...carbonization temperature and H3PO4 impregnation ratio on the product distributions were studied. Increasing the H3PO4 impregnation ratio (0–2.0) and carbonization temperature (600–750 °C) was found to enhance the selectivity of aromatics. When the activated carbon was synthesized using an H3PO4 impregnation ratio of 1:1 and a carbonization temperature of 700 °C, the yield of aromatics reached a maximum of 86.11% and the selectivity of mono-aromatics reached 64.01%. Moreover, the catalytic performances of biochars obtained at various carbonization temperatures were also studied. No significant catalytic activity of biochar for the formation of aromatics was observed due to the absence of P-containing active functional groups. This work provides an approach for the conversion of wood-plastic composite waste into valuable aromatic production using a low-cost activated carbon catalyst.
•Activated carbon was first applied to the pyrolysis of wood plastics composite.•P-containing activated carbon exhibited excellent catalytic performance.•High selectivity of aromatics (86.11%) were reached in obtained pyrolysis oil.•It provides an approach for converting WPC wastes into aromatics production.
The commercialization of proton solid oxide fuel cells (H-SOFCs) is hindered by the lack of high active and durable cathode materials exposed to evil operation conditions. Here, this groundbreaking ...study addresses two critical challenges impeding the practicality of La0.6Sr0·4Co0·2Fe0·8O3-δ (LSCF), one of the most popular proton-conducting cathode materials contemporarily: inadequate temperature activity and durability issues stemming from surface Sr segregation. The research introduces a transformative solution through the creation of a novel nanofiber cathode, denoted as PrBaCo1.4Fe0·6O6-δ@LSCF, comprising a nanoscale LSCF FP host and PBCF NP guest. Advanced electron microscopy and scanning electron microscopy techniques confirm the seamless integration of the two phases, highlighting a distinctive fiber structure adorned with impregnated nanoparticles. Meanwhile, efficiently reducing oxygen vacancies within the LSCF bulk phase significantly suppresses Sr segregation. Systematic simulations based on density functional theory reveal that the incorporation of PSCF reduces the polarization energy barrier. In practical terms, electrochemical testing of a single cell supported by PBCF@LSCF shows a polarization resistance of only 0.053 Ω cm2 at 700 °C, translating to a remarkable fifty percent reduction. Furthermore, a sustained 100-h test reveals no notable decline in performance. Consequently, a novel dual modification approach is proposed for crafting cathodes tailored for SOFCs.
•PBCF is impregnated in the LSCF cathode of H-SOFCs.•Sr segregation is substantially suppressed.•No significant degradation is detected under long-term operation.
SiO2 and γ‐Al2O3 impregnation with nominal 10 and 20% of cobalt was examined using wet impregnation method starting with Co(NO3)2·6H2O. The samples were dried and analyzed by XPS prior to calcination ...to study the surface species in the solids and the role of the support in the processing of supported cobalt catalysts. The results showed that cobalt introduction alters the few top nanometers of the support materials as there are significant changes recorded in the XPS spectra. Most importantly, there is a remarkable similarity between the O 1s XPS signal of SiO2 and γ‐Al2O3 following Co 20% impregnation, which suggests that these materials could have similar properties in terms of the oxidation ability and the general redox behavior. The shift of Al 2p peaks to higher binding energy (BE) in the XPS investigations and the shift of Si 2p peaks to lower BE were observed for high nominal cobalt loading. These results suggest that the choice of the support in cobalt‐based catalysts would tune the chemical characteristics of cobalt in the final materials.
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•Both physisorption and chemisorption of Hg0 occurred on the surface of M6WN5.•Chemisorption process was an absolute predominant route for Hg0 removal by M6WN5.•The effect of NO, H2O, ...SO2 and O2 on Hg0 removal by M6WN5 was investigated.•M6WN5 demonstrated to be a promising Hg0 sorbent in flue gas.
Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH4Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg0 occurred on the surface of M6WN5 which was modified both microwave and 5wt.% NH4Cl loading, and exothermic chemisorption process was a dominant route for Hg0 removal. Microwave activation improved pore properties and NH4Cl impregnation introduced good active sites for biochars. The presence of NO and O2 increased Hg0 adsorption whereas H2O inhibited Hg0 adsorption greatly. A converse effect of SO2 was observed on Hg0 removal, namely, low concentration of SO2 promoted Hg0 removal obviously whereas high concentration of SO2 suppressed Hg0 removal. The Hg0 removal by M6WN5 was mainly due to the reaction of the CCl with Hg0 to form HgCl2, and the active state of CCl* groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg0 sorbent in flue gas when compared with other sorbents.
•Pyrolysis of H2SO4-impregnated corncobs selectively produced anhydrosugars/furfural.•The maximum yields were obtained from 2.75 wt% H2SO4-impregnated corncobs.•H2SO4 acted as inhibitor and catalyst ...during pyrolysis of H2SO4-impregnated corncobs.
The objective of this study was to selectively coproduce anhydrosugars and furfural from the fast pyrolysis of biomass by H2SO4 impregnation. The pyrolysis behaviors of raw and H2SO4-impregnated corncobs, cellulose and xylan were systematically studied by a thermogravimetric analyzer (TGA) and commercial pyroprobe reactor. The results demonstrate that H2SO4 impregnation can reduce the formation of char and drastically improve the yield of anhydrosugars and furfural. The maximum yields of levoglucosan (38.45 wt% based on cellulose), furfural (19.18 wt% based on hemicellulose) and xylosan (9.49 wt% based on hemicellulose) were obtained by fast pyrolysis of corncobs impregnated with 2.75 wt% H2SO4. By comparing the product distributions from fast pyrolysis of H2SO4-impregnated cellulose, xylan, and raw and demineralized corncobs, it is concluded that H2SO4 can act as an inhibitor to suppress the catalytic functions of structural alkali and alkaline earth metals (AAEM) to improve the yield of anhydrosugars, and H2SO4 can also act as a catalyst to accelerate the dehydration of hemicellulose to form more furfural. It is speculated that H2SO4 could first react with structural AAEM in lignin to form lignosulfonates (e.g., potassium lignosulfonate), thus reducing the catalytic functions of structural AAEM during fast pyrolysis of corncobs. These findings provide a simple and efficient method for the selective coproduction of anhydrosugars and furfural from waste biomass.
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•Supercritical impregnation of mesoglycan into alginate aerogel.•Topical innovative device to be applied on wounds to favor the re-epithelialization.•Pro-migratory role of the ...composite system MSG/CAA.
Mesoglycan (MSG) was impregnated onto calcium alginate aerogel (CAA) to produce an innovative topical device to be applied on wounds. The main purpose of the composite material is to favor the re‐epithelialization through a direct and immediate action, also offering a protective barrier to ensure a favorable and sterilized environment for the wound healing process. Impregnation kinetics and isotherms were determined at 18 MPa and 40 and 60 °C. Composite systems were analyzed using Field Emission Scanning Electron Microscopy (FESEM), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) and UV–vis spectroscopies. A functional assay of in vitro wound healing confirmed the pro-migratory role of the composite system MSG/CAA, since an increase of the migration rate on fibroblast (BJ) cells and of the covered distance for keratinocytes (HaCaT) was observed with MSG impregnated on CAA compared to non-treated cells, CAA and pure MSG.
The restricted operating temperature range of fibre-reinforced polymer (FRP) systems for upgrading and retrofitting reinforced concrete structures is among the key limiting factors of this ...technology. Indeed, an alternative reinforcing system, known as Mineral-impregnated Carbon-Fibre (MCF), has recently emerged to address this issue. This paper presents an experimental investigation of the performance of MCF systems embedded in fine-grained, Alkali-Activated Concrete (AAC), which have been pre-heated at 100°C (or 200°C) and then tested in pull-out at the target temperature. For the purpose of assessing the bond quality against thermal exposure, results are compared with the control group (ambient temperature 20°C), as well as with an epoxy-impregnated commercial roving. In addition, specimens are characterised at the fibre-to-matrix interface by microscopy and by physical–chemical analytical techniques. Experimental data are fitted onto a one-dimensional stress-and-friction analytical model to determine the characteristic properties of the temperature-dependent bond–slip behaviour of MCFs. Findings suggest enhanced chemical compatibility and reinforcing capabilities at elevated temperature for MCFs, primarily ascribed to the impregnation quality and to the AAC capacity to withstand thermal strain.
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•Bond of mineral-impregnated carbon fibre (MCF) in alkali-activated concrete is studied up to 200 °C.•A 1D stress-friction model is used to monitor the change in bond properties of MCF.•No stress transfer for epoxy based CF at 200 °C, whereby MCF retain more than 50% of their bond strength.•Profiling of MCF affects internal cracking and bond quality.•Bonding behaviour of smooth MCF proves to be the most stable up to 200 °C.
Non-healing wounds are among the serious complications of type-2-diabetes around the globe, associated with high incidence of bacterial infection, chronic nerve and blood vessel damage, and ...eventually repeated amputation of limbs and organs. Silver nanoparticles offer strong wound healing potential due to their well-known antibacterial activities. The present study reports the development of silver nanoparticle impregnated chitosan-poly ethylene glycol (PEG) hydrogel to accelerate wound healing in diabetic patients. The aim of the study was to formulate a sustained and slow release of silver nanoparticle using chitosan-PEG-Silver Nitrate based hydrogel for the treatment of chronic diabetic wounds. The silver nanoparticle containing chitosan-PEG pre-polymer solution was synthesized by reducing silver nitrate with PEG and chitosan solution, thereby, transforming the silver ions into silver nanoparticles. The resulted pre-polymer solution was then crosslinked using glutaraldehyde to form the desired hydrogel. The developed silver nanoparticle impregnated chitosan hydrogel was characterized using ultra-violet (UV) visible spectrophotometry, Fourier Transform-infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) followed by the determination of porosity, and swelling properties. The release of AgNPs from hydrogel was determined by UV-vis spectroscopy followed by antimicrobial and antioxidant assays. The wound healing efficacy of the synthesized hydrogel was evaluated in diabetic rabbits. The results demonstrated a higher porosity, higher degree of swelling and higher water vapor transition rate (WVTR) for silver nanoparticle impregnated hydrogel compared to bare chitosan-PEG hydrogel as well as improved antimicrobial and antioxidant properties in-vitro and enhanced wound healing capability in-vivo in diabetic rabbits. The hydrogel showed a slow and sustained release of AgNPs over a period of at least seven days manifesting the slow biodegradation of developed hydrogels. The improved antimicrobial, antioxidant and wound healing results indicate that the silver nanoparticle impregnated chitosan-PEG hydrogel can be a promising material for wound healing dressing for chronic diabetic wounds.
