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Nanomaterials (Basel, Switzerland) Jun 2024The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of...
The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) and loading nickel onto ordered carbon soot. The present study aimed to investigate the effect of the Ni nanoparticles content on the electrocatalytic performance of Ni-CS, ultimately leading to the identification of a maximum composition. The presence of an excessive quantity of nickel particles leads to a decrease in the number of active sites within the material, resulting in sluggishness of the electron transfer pathway. The electrocatalyst composed of nickel and carbon support, with a nickel content of 20 wt%, has demonstrated a noteworthy current activity of 18.43 mA/cm, which is three times that of the electrocatalyst with a higher nickel content of 25 wt%. For example, the 20 wt% Ni-CS electrocatalytic activity was found to be good, and it was approximately four times higher than that of 20 wt% Ni-CB (nickel-carbon black). Moreover, the chronoamperometry (CA) test demonstrated a reduction in current activity of merely 65.80% for a 20 wt% Ni-CS electrocatalyst, indicating electrochemical stability. In addition, this demonstrates the great potential of candle soot with Ni nanoparticles to be used as a catalyst in practical applications.
PubMed: 38921918
DOI: 10.3390/nano14121042 -
Journal of Hazardous Materials Jun 2024The content of active lattice oxygen and oxygen vacancies is crucial for the catalytic oxidation of soot. Herein, we adjust the Pr-O bond strength in PrO by doping...
The content of active lattice oxygen and oxygen vacancies is crucial for the catalytic oxidation of soot. Herein, we adjust the Pr-O bond strength in PrO by doping several common transition metals (Mn, Fe, Co, Ni) to promote the formation of oxygen vacancies and the activation of lattice oxygen. This strategy does not compromise its crystal structure, allowing for improved catalytic performance while maintaining stability. The Mn-doped PrO catalyst shows the best soot catalytic oxidation performance. Its T (the temperature of soot conversion reaching 50 %) value is 396 °C under loose contact. Further characterizations and density functional theory (DFT) calculations demonstrate that PMO possesses a large specific surface area. Additionally, the weakening the strength of the Pr-O bond leaded to an increase in oxygen vacancies, which in turn enhanced the redox ability of catalyst. This work will provide a reference for the development of Pr-based catalysts for soot combustion.
PubMed: 38917632
DOI: 10.1016/j.jhazmat.2024.135010 -
Scientific Reports Jun 2024To achieve high-efficiency combustion of heavy fuel oil (HFO), this study investigated the combustion characteristics of methanol/HFO droplets with methanol content from...
To achieve high-efficiency combustion of heavy fuel oil (HFO), this study investigated the combustion characteristics of methanol/HFO droplets with methanol content from 10 to 30% using the suspension method under ambient temperature from 923 to 1023 K. The combustion of methanol/HFO droplets was summarized as a two-phase process consisting of six typical stages, emphasizing liquid phase. Especially, the fluctuation evaporation stage, induced by frequent and intense puffing, was identified as prominent character. Both the ignition delay and lifetime of HFO and methanol/HFO droplets decreased with increasing ambient temperatures. For the methanol/HFO droplet, the ignition delay and droplet lifetime increased with the increasing methanol content. Prominently, compared to HFO, HM10 had the most significant reduction in droplet lifetime and TINL under the same operating conditions, which indicated that the addition of 10% methanol accelerated the combustion process and reduced soot generation. Additionally, the thermos-dynamic characteristics of methanol/HFO droplets were investigated. Puffing was primarily attributed to superheating of methanol and pyrolysis of heavy components in HFO, which resulted in active and passive rupture of bubbles. Similarity and maximum deformation were employed to qualitatively distinguish between them. The obtained findings aimed to develop a promising alternative fuel to reduce emissions and preserve energy.
PubMed: 38914642
DOI: 10.1038/s41598-024-64482-x -
Unconventional gas-phase synthesis of biphenyl and its atropisomeric methyl-substituted derivatives.Physical Chemistry Chemical Physics :... Jun 2024The biphenyl molecule (CH) acts as a fundamental molecular backbone in the stereoselective synthesis of organic materials due to its inherent twist angle causing...
The biphenyl molecule (CH) acts as a fundamental molecular backbone in the stereoselective synthesis of organic materials due to its inherent twist angle causing atropisomerism in substituted derivatives and in molecular mass growth processes in circumstellar environments and combustion systems. Here, we reveal an unconventional low-temperature phenylethynyl addition-cyclization-aromatization mechanism for the gas-phase preparation of biphenyl (CH) along with -, -, and -substituted methylbiphenyl (CH) derivatives through crossed molecular beams and computational studies providing compelling evidence on their formation bimolecular gas-phase reactions of phenylethynyl radicals (CHCC, XA) with 1,3-butadiene- (CD), isoprene (CHC(CH)CHCH), and 1,3-pentadiene (CHCHCHCHCH). The dynamics involve de-facto barrierless phenylethynyl radical additions submerged barriers followed by facile cyclization and hydrogen shift prior to hydrogen atom emission and aromatization to racemic mixtures (, ) of biphenyls in overall exoergic reactions. These findings not only challenge our current perception of biphenyls as high temperature markers in combustion systems and astrophysical environments, but also identify biphenyls as fundamental building blocks of complex polycyclic aromatic hydrocarbons (PAHs) such as coronene (CH) eventually leading to carbonaceous nanoparticles (soot, grains) in combustion systems and in deep space thus affording critical insight into the low-temperature hydrocarbon chemistry in our universe.
PubMed: 38912536
DOI: 10.1039/d4cp00765d -
The Science of the Total Environment Jun 2024When smelting silicon manganese alloy in an industrial electric furnace, it will produce smoke and dust waste gas, which can be utilized again back to the furnace and...
When smelting silicon manganese alloy in an industrial electric furnace, it will produce smoke and dust waste gas, which can be utilized again back to the furnace and improve the utilization rate of raw materials after a particular trapping device and collection treatment. However, at higher moisture levels, they are prone to explode. Effects of various initial masses, initial moisture contents, and microwave output powers on the soot ash of smelting silicon manganese alloy were studies. The findings indicate that the microwave drying rate increases with all three variables. The time for complete microwave drying is directly proportional to the sample's initial moisture content and the sample's initial mass, and the time for complete microwave drying is inversely proportional to the microwave output power. The results demonstrate that the Modified Page model can accurately describe the microwave drying process. The experimental data were fitted experimentally by drying kinetic models. Microscopic characterization of soot ash from refining silico‑manganese alloys before and after drying was carried out using FTIR and SEM. Through FTIR characterization, the peak value of the -OH absorption peak decreases upon drying, and SEM results in no agglomeration caused by microwave drying and better dispersion of the soot ash of the dried smelted silica‑manganese alloys, all of which proved that microwaves could effectively remove water. It was discovered that the diffusion coefficient increased gradually with increasing power when it was computed using Fick's second law. The diffusion coefficient increases and then decreases as the moisture content increases. The diffusion coefficient decreases as the initial mass increases. Activation energy of microwave drying of soot ash from the refining of silicomanganese alloys was calculated to be -1.4467 W/g. Its purpose is to offer a detailed guide for the industrial drying of soot ash from silicomanganese alloy refinement using microwave drying technology.
PubMed: 38908601
DOI: 10.1016/j.scitotenv.2024.174105 -
The Science of the Total Environment Jun 2024Due to environmental pollution and energy crises, zero‑carbon fuel ammonia (NH) has attracted extensive attention as an alternative fuel for engines. In this paper,...
Due to environmental pollution and energy crises, zero‑carbon fuel ammonia (NH) has attracted extensive attention as an alternative fuel for engines. In this paper, the effects of ammonia energy ratio (AER) and injection strategy on particulate emission characteristics of an ammonia diesel dual-fuel engine were examined by merging experimental and simulation results; additionally, soot formation and oxidation mechanism were investigated. Results showed that the reduction in particulate emission was substantially higher than the increase in AER. When AER increased to 60 %, the reduction in particulate mass concentration reached 97.5 %. The initial soot formation area gradually moved to the bottom of the piston bowl with increasing AER. When the piston reached the top dead center, the high-soot-concentration area was shifted to the center of the piston bowl as AER increased. The contents of acetylene (CH) and methyl (CH) reduced considerably, which restricted the formation of soot precursors. With AER increasing, the contents of nitric oxides (NO) and other nitrogen-containing species increased and reacted with CH and other carbon-containing species, which effectively reduced the number of C in soot formation pathway, thereby lowering particulate emissions. As AER increased, hydroxyl (OH) involved in soot formation gradually decreased, and only 14 % of OH was involved in the oxidation of n-heptane at 60 % AER, which was favorable for reducing the soot formation rate. Furthermore, OH is a substantial species in soot oxidation. The introduction of ammonia caused an increase in OH, which facilitated the removal of soot. The decrease in hydrogenium (H) hindered the hydrogen-abstraction-acetylene-addition (HACA) reaction, further limiting the soot surface growth. By optimizing the injection timing and AER, particulate emission was lowered to 4.31 × 10 μg/cm, and particle size was reduced by 64.2 % when AER was 60 %, injection timing was -20° CA ATDC, and injection pressure was 60 MPa.
PubMed: 38906287
DOI: 10.1016/j.scitotenv.2024.174096 -
Environmental Science & Technology Jun 2024Polycyclic aromatic hydrocarbons (PAHs) are the primary organic carbons in soot. In addition to PAHs with even carbon numbers (PAH), substantial odd-carbon PAHs (PAH)...
Polycyclic aromatic hydrocarbons (PAHs) are the primary organic carbons in soot. In addition to PAHs with even carbon numbers (PAH), substantial odd-carbon PAHs (PAH) have been widely observed in soot and ambient particles. Analyzing and understanding the photoaging of these compounds are essential for assessing their environmental effects. Here, using laser desorption ionization mass spectrometry (LDI-MS), we reveal the substantially different photoreactivity of PAH from PAH in the aging process and their MS detection through their distinct behaviors in the presence and absence of elemental carbon (EC) in soot. During direct photooxidation of organic carbon (OC) alone, the PAH are oxidized more rapidly than the PAH. However, the degradation of PAH becomes preponderant over PAH in the presence of EC during photoaging of the whole soot. All of these observations are proposed to originate from the more rapid hydrogen abstraction reaction from PAH in the EC-photosensitized reaction, owing to its unique structure of a single -hybridized carbon site. Our findings reveal the photoreactivity and reaction mechanism of PAH for the first time, providing a comprehensive understanding of the oxidation of PAHs at a molecular level during soot aging and highlight the enhanced effect of EC on PAH ionization in LDI-MS analysis.
PubMed: 38899536
DOI: 10.1021/acs.est.4c00764 -
Materials (Basel, Switzerland) May 2024Triboelectric nanogenerators (TENGs) have emerged as viable micro power sources for an array of applications. Since their inception in 2012, TENGs have been the subject...
Triboelectric nanogenerators (TENGs) have emerged as viable micro power sources for an array of applications. Since their inception in 2012, TENGs have been the subject of significant advancements in terms of structural design and the development of friction materials. Despite these advancements, the complexity of their structural designs and the use of costly friction materials hinder their practical application. This study introduces a simplified TENG model utilizing an economical composite film of fullerene carbon soot (FS)-doped polydimethylsiloxane (PDMS) (FS-TENG). It confirms the FS-TENG's ability to convert mechanical energy into electrical energy, as demonstrated through experimental validation. The generated electricity by the FS-TENG can power devices such as light-emitting diodes (LEDs), digital watches, kitchen timers, and sports stopwatches, highlighting its efficiency. This research enhances the development of TENGs featuring low-cost, streamlined structures for sustainable and autonomous energy sensing applications.
PubMed: 38893734
DOI: 10.3390/ma17112470 -
Journal of Environmental Health Science... Jun 2024This study aimed to present an index () to evaluate the environmental performance of the sugar-energy industrial process based on the waste generated in manufacturing...
PURPOSE
This study aimed to present an index () to evaluate the environmental performance of the sugar-energy industrial process based on the waste generated in manufacturing operations. The residues considered in this study were: vinasse, filter cake, ash and soot, residual waters, and sewage sludge.
METHODS
The index created was developed to take into account, and to be directly proportional to the environmental impact of each residue generated by the sugar-energy production, to the relative spatial dispersion that each waste can reach, and to the environmental fragility of the hydrographic basin where the plant under evaluation is inserted and works. The lower IEP, the better the company valuation.
RESULTS
The index was tested in a real company and exhibited an = 1,4.10 km.p/yr, which shows weak waste management by the enterprise. Vinasse was responsible for 50% of the while filter cake contributed 45% to it. Ash and soot, residual waters, and sewage sludge were together responsible for 5% of the .
CONCLUSION
The theoretical conception used in this study is inspiring for the development of new studies on environmental assessment measurement. The study showed that vinasse is the most problematic waste in environmental terms, a conclusion that is in line with academic studies. Nevertheless, the waste with the greatest potential impact on the environment is filter cake. Despite this, filter cake presented a lower than vinasse, given that its negative impact on the basin is smaller. Both wastes contributed 95% of the , which places them among the residues to be managed with greater attention.
PubMed: 38887769
DOI: 10.1007/s40201-023-00880-z -
ACS Applied Materials & Interfaces Jun 2024Herein, we report a dual-functional flexible sensor (DFFS) using a magnetic conductive polymer composed of nickel (Ni), carbon black (CB), and polydimethylsiloxane...
Herein, we report a dual-functional flexible sensor (DFFS) using a magnetic conductive polymer composed of nickel (Ni), carbon black (CB), and polydimethylsiloxane (PDMS). The material selection for the DFFS utilizes the excellent elasticity of the PDMS matrix and the synergistic interaction between Ni and CB. The DFFS has a wide strain range of 0-170%, a high sensitivity of 74.13 (140-170%), and a low detection limit of 0.3% strain. The DFFS based on superior performance can accurately detect microstrain/microvibration, oncoming/contacting objects, and bicycle riding speed. Additionally, the DFFS can be used for comprehensive monitoring of human movements. Therefore, the DFFS of this work shows significant value for implementation in intelligent wearable devices and noncontact intelligent control.
Topics: Dimethylpolysiloxanes; Humans; Nickel; Wearable Electronic Devices; Microspheres; Soot; Movement; Electric Conductivity
PubMed: 38870327
DOI: 10.1021/acsami.4c04830