Elaidic acid(EA)is a typical trans fatty acid(TFA)that emerges during the processing of various fatty foods.In this study,we found that EA induced renal injury with necroptosis.Pretreatment with a reactive oxygen spec...Elaidic acid(EA)is a typical trans fatty acid(TFA)that emerges during the processing of various fatty foods.In this study,we found that EA induced renal injury with necroptosis.Pretreatment with a reactive oxygen species(ROS)inhibitor and a RIPK3 inhibitor alleviated EA-induced necroptosis.The data indicated that EA induced renal necroptosis through ROS/RIPK3/MLKL pathway.In mechanistic studies,we explored how EA induced ROS production.Results indicated that EA caused mitochondrial damage by testing MMP,MFN1,VDAC,and FIS1.Further,EA suppressed mitophagy by testing the levels of LC3,p62,PINK1,Parkin,colocalization of LC3 and Mito-Tracker Red.Mitophagy is a process of selective degradation of damaged mitochondria.A large number of damaged mitochondria couldn't be cleared by mitophagy in time,which increased ROS levels in renal cells.Pretreatment with a mitophagy activator decreased EA-induced ROS levels and mitochondrial damage.Taken together,our data identified that EA induced renal necroptosis by destroying mitochondria and inhibiting mitophagy,thereby activating the ROS/RIPK3/MLKL pathway.展开更多
Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because ...Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because it has a high specific surfacearea for sulfur loading.We have developed a pressurizedphysical activation(PPA)method that producedan activated carbon(PPAC)with a high specific surfacearea comparable to that of CAC.The pore structure of PPAC could be changed and its use as a cathode material for Li–Sbatteries was investigated.Battery tests at different capacity rates(C-rates)showed that it had a much improved high-rate performancewith a discharge capacity of 900 mAh/(g of sulfur)at 1 C,in contrast to only 600 mAh/(g of sulfur)for CAC.Porestructure analyses showed that PPAC prepared at a high activation temperature(1000℃)had unusual channel-like mesoporesbetween the microdomains that are the basic structural units of artificial carbon materials.These are connected to microporesdeveloped in each microdomain,and deliver ions from the surroundings to the internal pores and vice versa.The well-developedmicropores and mesopores of PPAC respectively ensured the high adsorption of lithium polysulfides and a high rate ofion diffusion.Compared to CAC,PPAC is a high-performance,low-cost cathode material that is promising for use in futureLi–S batteries.展开更多
Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face wit...Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed Csingle bondH activation has been employed for the functionalization of amino acids and peptides.Through domino Csingle bondH activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed Csingle bondH activation/annulation.展开更多
To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electro...Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.展开更多
The activation of pancreatic stellate cells(PSCs)and the secretion of inflammatory factors play critical roles in the development of pancreatic fibrosis.While gambogic acid(GA),a flavonoid with anti-tumor properties,h...The activation of pancreatic stellate cells(PSCs)and the secretion of inflammatory factors play critical roles in the development of pancreatic fibrosis.While gambogic acid(GA),a flavonoid with anti-tumor properties,has been studied,its role in this process remains unclear.This study demonstrated that GA promoted YAP1 degradation and reduced its nuclear localization,thereby inhibiting PSC activation and the progression of pancreatic fibrosis.GA inhibited PSC proliferation,decreasedα-smooth muscle actin(α-SMA)expression,and reduced lipid droplets in LTC14 and primary mouse PSCs(mPSCs).Additionally,GA suppressed the expression of inflammatory factors[nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),nuclear factor erythroid 2-related factor 2(NRF2),interleukin-6(IL-6),tumor necrosis factorα(TNF-α),and nuclear factorκB(NF-κB)]in PSCs and counteracted the transforming growth factor(TGF)-β-induced increase in these proteins.GA also reduced collagenΙand tissue inhibitor of metalloproteinase-1(TΙMP1)expression,thereby attenuating fibrosis.Mechanistically,GA decreased YAP1 expression and nuclear translocation and reversed TGF-β-induced YAP1 upregulation.YAP1 overexpression abrogated GA’s inhibitory effects on PSC activation and inflammation.Furthermore,GA activated the Hippo pathway,increased phosphorylated(p)-LATS1 and p-YAP levels,and promoted ubiquitin-mediated YAP1 degradation.In vivo studies confirmed that GA inhibited dibutyltin dichloride(DBTC)-induced pancreatic fibrosis via suppressing YAP1 and NF-κB in BALB/c mice.In conclusion,GA activates the Hippo pathway and promotes YAP1 translocation to the cytoplasm,leading to its degradation and subsequent inhibition of PSC activation and fibrosis.These findings highlight the critical role of ubiquitin-mediated YAP1 degradation in regulating PSC activity and offer novel insights into the therapeutic potential of GA for treating pancreatic fibrosis.展开更多
Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a po...Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.展开更多
The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborat...The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.展开更多
A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescenc...A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.展开更多
As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This stud...As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This study prepared surface polarity-modified ACF using the heteroatom doping method.The modified ACF possessed a richer array of strongly polar oxygen/nitrogen-containing functional groups(primarily phenolic hydroxyl and lactone groups),a larger specific surface are1,and a more developed micropore structure.The adsorption capacities of ethanol for O-ACF and N-ACF were 4.110 mmol/g and 1.698 mmol/g,respectively,which were 11.3 times and 4.7 times those of unmodified ACF.This was a significant improvement over our previous work(0.363 mmol/g).The improvement of adsorption capacity for the N-ACF was mainly due to the higher specific surface are1,greater number of micropores(more adsorption sites)and abundant existence of defects,whereas,for O-ACF,the improvement mainly relied on the abundant presence of oxygen-containing functional groups on the surface.However,water had a negative effect on the adsorption of ethanol for the modified ACF due to competitive adsorption and the disappearance of capillary condensation.It was further revealed that the adsorption process of ethanol and water was quite different.It obeyed the linear driving force(LDF)model for ethanol adsorption,however,the intraparticle diffusion(IPD)model for water adsorption.展开更多
Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targ...Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targeted contaminant in advanced oxidation processes(AOPs).Herein,we investigated the removal of HA in the alkali-activated biochar(KBC)/peroxymonosulfate(PMS)system.The modification of the original biochar(BC)resulted in an increased adsorption capacity and catalytic activity due to the introduction of more micropores,mesopores,and oxygen-containing functional groups,particularly carbonyl groups.Mechanistic insights indicated that HA is primarily chemically adsorbed on the KBC surface,while singlet oxygen(^(1)O_(2))produced by the PMS decomposition served as the major reactive species for the degradation of HA.An underlying synergistic adsorption and oxidation mechanism involving a local high concentration reaction region around the KBC interface was then proposed.This work not only provides a cost-effective solution for the elimination of HA but also advances our understanding of the nonradical oxidation at the biochar interface.展开更多
P-arsanilic acid(AA)has received widespread attention because of its conversion to more toxic inorganic arsenic compounds(arsenate and arsenite)in the natural ecosystems.Its removal process and mechanisms with co-exis...P-arsanilic acid(AA)has received widespread attention because of its conversion to more toxic inorganic arsenic compounds(arsenate and arsenite)in the natural ecosystems.Its removal process and mechanisms with co-existence of microplastics remain unkown.In this study,biochar loaded with nano zero-valent iron(nZVI)particles(ISBC)was prepared by using iron scrap obtained from a steel works and wood chips collected from a wood processing plant.The advanced oxidation system of sodium persulfate(PDS)activated by ISBC was applied for AA degradation and inorganic arsenic control in aqueous media.More than 99%of the AA was completely degraded by the ISBC/PDS system,and the As(III)on AA was almost completely oxidized to As(V)and finally removed by ISBC.HCO_(3)−inhibited the removal of AA by the ISBC/PDS system,while Cl^(−)had a dual effect that showing inhibition at low concentrations yet promotion at high concentrations.The effect of microplastics on the degradation of AA by the ISBC/PDS system was further investigated due to the potential for combined microplastic and organic arsenic contamination in rural/remote areas.Microplastics were found to have little effect on AA degradation in the ISBC/PDS system,while affect the transport of inorganic arsenic generated from AA degradation.Overall,this study provides new insights and methods for efficient removal of p-arsanilic acid from water with coexisting microplastics.展开更多
This study evaluates the effectiveness of microwave technology in producing activated carbon from lemongrass waste,an underutilized agricultural byproduct.Microwave-assisted production offers faster heating,lower ener...This study evaluates the effectiveness of microwave technology in producing activated carbon from lemongrass waste,an underutilized agricultural byproduct.Microwave-assisted production offers faster heating,lower energy consumption,and better process control compared to conventionalmethods.It also enhances pore development,resulting in larger,cleaner,and more uniform pores,making the activated carbon more effective for adsorption.The microwave-assisted process significantly accelerates production,reducing the required time to just 10 min at a power of 400 W.Activated carbon derived from lemongrass waste at 400 W exhibits a water absorption capacity of 7.88%,ash content of 5.51%,volatile matter of 6.96%,fixed carbon of 75.79%,and an iodine number of 790.97 g iodine/100 g.Scanning Electron Microscopy(SEM)analysis confirms the formation of larger,cleaner,and smoother pores,contributing to increased porosity and pore size.Additionally,Energy Dispersive X-ray(EDX)analysis identifies key elements in the lemongrass waste,with carbon being the dominant component at 75.57%.The Brunauer-Emmett-Teller(BET)surface area is measured at 818 m^(2)/g,with an average pore diameter of 1.91 nm,classifying the material as microporous.The activated carbon,meeting quality standards,is applied as an adsorbent in acid mine drainage(AMD)treatment,with varying mass concentrations introduced intowastewater samples.Adsorption tests confirmthat the microparticle carbon adsorption profile follows the Langmuir model,indicating a monolayer adsorption process.Furthermore,adsorption kineticswere analyzed over different time intervals,revealing that the process alignswith both pseudo-first-order(PFO)and pseudo-second-order(PSO)models,with all cases predominantly following the PFO rate equation.展开更多
Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving...Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving the solubility and bioavailability of WAS organic matter.Considering the energy consumption and chemical cost,this paper used low-dose nanozero-valent iron (NZVI) coupled with low-intensity ultrasonication (US) to pretreat WAS,and explored the effects of different treatment sequences on the fragmentation of WAS flocs particles,the dissolution of organic matter,and the subsequent biofermentation conversion process.The results showed low-dose NZVI synchronized with low-intensity US (NZVIUS)worked best for WAS anaerobic fermentation.Compared with 2062 mg/L in control group,soluble chemical oxygen demand (SCOD) after NZVIUS treatment reached up to 2786 mg/L during the fermentation cycle,and the initial release rate of SCOD increased by 69%.The VFAs production was elevated from 1522 to 1940 mg COD/L.NZVIUS pretreatment promoted the solubilization of attached organic matter,manifested by the fragmentation of WAS flocs and cell lysis.At the same time,proteins and carbohydrates in the extracellular polymeric substances (EPS) had different types of migration and transformation,and transfer of EPS can contribute 35.6% to SCOD.Moreover,adding NZVI promoted PO_(4)^(3-)-P recovery in the fermentation supernatant by 22.3% more than in day 4 control.This study demonstrated that the NZVIUS pretreatment method can effectively improve the production of VFAs by WAS anaerobic fermentation,meeting the practical needs of wastewater plants.展开更多
Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area a...Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.展开更多
Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uro...Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uronosyltransferases(UATs)to construct glycans containing uronic acids.Despite their biological importance,the synthesis of naturally occurring NDP-uronic acids on a large scale remains challenging.Here,we developed an oxidation reaction insertion strategy for the efficient synthesis of NDP-uronic acids,and 11 NDP-uronic acids were successfully prepared in good yield and on a large scale.The prepared NDP-uronic acids can be used to explore new uronosyltransferases and synthesize uronic acids containing carbohydrates for fundamental research.展开更多
Pt/activated carbon （Pt/AC） catalyst combined with base works efficiently for lactic acid production from glycerol under mild conditions. Base type （LiOH, NaOH, KOH, or Ba（OH）2） and base/glycerol molar ratio sig...Pt/activated carbon （Pt/AC） catalyst combined with base works efficiently for lactic acid production from glycerol under mild conditions. Base type （LiOH, NaOH, KOH, or Ba（OH）2） and base/glycerol molar ratio significantly affected the catalytic performance. The corresponding lactic acid selectivity was in the order of LiOH〉NaOH〉KOH〉Ba（OH）2. An increase in LiOH/glycerol molar ratio ele‐vated the glycerol conversion and lactic acid selectivity to some degree, but excess LiOH inhibited the transformation of glycerol to lactic acid. In the presence of Pt/AC catalyst, the maximum selec‐tivity of lactic acid was 69.3% at a glycerol conversion of 100% after 6 h at 90 °C, with a Li‐OH/glycerol molar ratio of 1.5. The Pt/AC catalyst was recycled five times and was found to exhibit slightly decreased glycerol conversion and stable lactic acid selectivity. In addition, the experimental results indicated that reaction intermediate dihydroxyacetone was more favorable as the starting reagent for lactic acid formation than glyceraldehyde. However, the Pt/AC catalyst had adverse effects on the intermediate transformation to lactic acid, because it favored the catalytic oxidation of them to glyceric acid.展开更多
The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts wer...The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts were prepared by an impregnation method using H3PO4‐activated Mt(Mt‐P)as the support.The catalysts were characterized using powder X‐ray diffraction,Fourier‐transform infrared spectroscopy,N2adsorption‐desorption,diffuse reflectance ultraviolet‐visible spectroscopy,temperature‐programmed desorption of NH3,and thermogravimetric analysis.The acid activation of Mt and WOx loaded on Mt‐P affected the strength and number of acid sites arising from H+exchange,the leaching of octahedral Al3+cations from Mt octahedral sheets,and the types of WOx(2.7≤x≤3)species(i.e.,isolated WO4/WO6‐containing clusters,two‐dimensional[WO6]polytungstates,or three‐dimensional WO3crystals).The strong acid sites were weakened,and the weak and medium acid sites were strengthened when the W loading on Mt‐P was12wt%(12%W/Mt‐P).The12%W/Mt‐P catalyst showed the highest catalytic activity.It gave a glycerol conversion of89.6%and an acrolein selectivity of81.8%at320°C.Coke deposition on the surface of the catalyst led to deactivation.展开更多
TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to es...TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate.展开更多
Commercially available coal-based activated carbon was treated by nitric acid with different concentrations and the resultant samples were used as catalysts for the direct hydroxylation of benzene to phenol in acetoni...Commercially available coal-based activated carbon was treated by nitric acid with different concentrations and the resultant samples were used as catalysts for the direct hydroxylation of benzene to phenol in acetonitrile. Boehm titration, X-ray photoelectron spectroscopy, scanning electron microscope coupled with an energy dispersive X-ray microanalyzer, and Brunauer-Emmett-Teller method were used to characterize the samples. The number of carboxyl groups on the surface was found to be the main factor affecting the catalytic activity. An optimum catalytic performance with a yield of 15.7% and a selectivity of 87.2% to phenol was obtained.展开更多
基金supported by National Key Research and Development Program of China(2023YFD1800902).
文摘Elaidic acid(EA)is a typical trans fatty acid(TFA)that emerges during the processing of various fatty foods.In this study,we found that EA induced renal injury with necroptosis.Pretreatment with a reactive oxygen species(ROS)inhibitor and a RIPK3 inhibitor alleviated EA-induced necroptosis.The data indicated that EA induced renal necroptosis through ROS/RIPK3/MLKL pathway.In mechanistic studies,we explored how EA induced ROS production.Results indicated that EA caused mitochondrial damage by testing MMP,MFN1,VDAC,and FIS1.Further,EA suppressed mitophagy by testing the levels of LC3,p62,PINK1,Parkin,colocalization of LC3 and Mito-Tracker Red.Mitophagy is a process of selective degradation of damaged mitochondria.A large number of damaged mitochondria couldn't be cleared by mitophagy in time,which increased ROS levels in renal cells.Pretreatment with a mitophagy activator decreased EA-induced ROS levels and mitochondrial damage.Taken together,our data identified that EA induced renal necroptosis by destroying mitochondria and inhibiting mitophagy,thereby activating the ROS/RIPK3/MLKL pathway.
文摘Lithium–sulfur(Li–S)batteries are promisingcandidates for next-generation energy storagegiven their high energy density and potential low cost.Chemically activated carbon(CAC)is often used fortheir cathodes,because it has a high specific surfacearea for sulfur loading.We have developed a pressurizedphysical activation(PPA)method that producedan activated carbon(PPAC)with a high specific surfacearea comparable to that of CAC.The pore structure of PPAC could be changed and its use as a cathode material for Li–Sbatteries was investigated.Battery tests at different capacity rates(C-rates)showed that it had a much improved high-rate performancewith a discharge capacity of 900 mAh/(g of sulfur)at 1 C,in contrast to only 600 mAh/(g of sulfur)for CAC.Porestructure analyses showed that PPAC prepared at a high activation temperature(1000℃)had unusual channel-like mesoporesbetween the microdomains that are the basic structural units of artificial carbon materials.These are connected to microporesdeveloped in each microdomain,and deliver ions from the surroundings to the internal pores and vice versa.The well-developedmicropores and mesopores of PPAC respectively ensured the high adsorption of lithium polysulfides and a high rate ofion diffusion.Compared to CAC,PPAC is a high-performance,low-cost cathode material that is promising for use in futureLi–S batteries.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20220409)the National Natural Science Foundation of China(No.22401153)+2 种基金the FWO[Fund for Scientific Research-Flanders(Belgium)]for financial support(recipient Erik V.Van der Eycken)the Research Council of the KU Leuven(recipient Erik V.Van der Eycken)the support of the"RUDN University Strategic Academic Leadership Program"(recipient Erik V.Van der Eycken).
文摘Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed Csingle bondH activation has been employed for the functionalization of amino acids and peptides.Through domino Csingle bondH activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed Csingle bondH activation/annulation.
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金the financial support from the National Natural Science Foundation of China(52172110,52472231,52311530113)Shanghai"Science and Technology Innovation Action Plan"intergovernmental international science and technology cooperation project(23520710600)+1 种基金Science and Technology Commission of Shanghai Municipality(22DZ1205600)the Central Guidance on Science and Technology Development Fund of Zhejiang Province(2024ZY01011)。
文摘Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.
基金supported by the Fundamental Research Funds for the Central Universities (No. 2632024TD07).
文摘The activation of pancreatic stellate cells(PSCs)and the secretion of inflammatory factors play critical roles in the development of pancreatic fibrosis.While gambogic acid(GA),a flavonoid with anti-tumor properties,has been studied,its role in this process remains unclear.This study demonstrated that GA promoted YAP1 degradation and reduced its nuclear localization,thereby inhibiting PSC activation and the progression of pancreatic fibrosis.GA inhibited PSC proliferation,decreasedα-smooth muscle actin(α-SMA)expression,and reduced lipid droplets in LTC14 and primary mouse PSCs(mPSCs).Additionally,GA suppressed the expression of inflammatory factors[nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),nuclear factor erythroid 2-related factor 2(NRF2),interleukin-6(IL-6),tumor necrosis factorα(TNF-α),and nuclear factorκB(NF-κB)]in PSCs and counteracted the transforming growth factor(TGF)-β-induced increase in these proteins.GA also reduced collagenΙand tissue inhibitor of metalloproteinase-1(TΙMP1)expression,thereby attenuating fibrosis.Mechanistically,GA decreased YAP1 expression and nuclear translocation and reversed TGF-β-induced YAP1 upregulation.YAP1 overexpression abrogated GA’s inhibitory effects on PSC activation and inflammation.Furthermore,GA activated the Hippo pathway,increased phosphorylated(p)-LATS1 and p-YAP levels,and promoted ubiquitin-mediated YAP1 degradation.In vivo studies confirmed that GA inhibited dibutyltin dichloride(DBTC)-induced pancreatic fibrosis via suppressing YAP1 and NF-κB in BALB/c mice.In conclusion,GA activates the Hippo pathway and promotes YAP1 translocation to the cytoplasm,leading to its degradation and subsequent inhibition of PSC activation and fibrosis.These findings highlight the critical role of ubiquitin-mediated YAP1 degradation in regulating PSC activity and offer novel insights into the therapeutic potential of GA for treating pancreatic fibrosis.
基金supported by National Natural Science Foundation of China(31730091,32372900,32072743)Natural Science Foundation of Sichuan Province(2023NSFSC0237)Major Science and Technology Projects in Sichuan Province(2021ZDZX0009)。
文摘Background Diarrhea remains a major health concern in both young animals and humans.Prevotella spp.,a dominant commensal genus in the healthy porcine gut,becomes increasingly abundant following weaning,suggesting a potential role during this critical transitional period.However,its involvement in post-weaning diarrhea remains poorly understood.Here,we aim to elucidate the role and underlying mechanisms of Prevotella in alleviating diarrhea in weaned piglets.Results To model unsanitary housing conditions,piglets were housed in uncleaned pens containing residual fecal matter from previous occupants and exposed to cold stress by maintaining the ambient temperature at 19℃,below the optimal 28℃.Under these conditions,piglets were orally administered either a blank medium(CON,n=10×2)or Prevotella copri at 1×10^(8)CFU(Pc,n=10×2)on d 1,3,and 5.After 28 d,cold stress induced a diarrhea incidence of 33.45%in the CON group,while P.copri supplementation significantly reduced the diarrhea rate to 19.73%.Treatment with P.copri markedly improved intestinal morphology in the small intestine,decreased serum levels of lipopolysaccharide(LPS)and intestinal fatty acid-binding protein(i-FABP),and enhanced total antioxidant capacity(T-AOC)and catalase(CAT)activity.Quantitative PCR and 16S rRNA gene sequencing revealed that P.copri significantly increased the colonic abundance of Prevotella,reshaping both the composition and functional profile of the gut microbiota.Moreover,P.copri enhanced the modularity and robustness of microbial ecological networks.Untargeted metabolomic profiling of colonic contents revealed a significant enrichment of metabolites involved in the arachidonic acid pathway following P.copri supplementation.In parallel,untargeted metabolomics of P.copri culture supernatants identified differential metabolic pathways including metabolic pathways,biosynthesis of secondary metabolites,and biosynthesis of antibiotics.In vitro assays demonstrated that P.copri-derived metabolites inhibited the growth of three common porcine intestinal pathogens.Furthermore,both P.copri metabolites and arachidonic acid enhanced intestinal barrier integrity and suppressed TNF-α-induced inflammation and apoptosis in Caco-2 cells through activation of the AHR–Nrf2 signaling pathway.Conclusions These findings highlight the role of P.copri in maintaining gut homeostasis and provide new insights into microbiota-based interventions for early-life intestinal disorders.
基金supported by the Russian Science Foundation (No. 25-13-00300)the Centre for Optical and Laser Materials Research (SPbSU) and Saint Petersburg State University for measuring the quantum yields of luminescence within the framework of research project(No.125021902439-8)。
文摘The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.
文摘A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.
基金supported by the National Key R&D Program of China(Nos.2022YFB4101500 and 2022YFE0209500)the National Natural Science Foundation of China(Nos.22276191 and 21976177)the Qinghai Province Air Pollution Assessment and Fine Management Support Project,and the University of Chinese Academy of Science.
文摘As a potential adsorption material,it is still a challenge for activated carbon fiber(ACF)in efficient adsorption of ethanol due to its nonpolar surface,which is mainly emitted from the grain drying industry.This study prepared surface polarity-modified ACF using the heteroatom doping method.The modified ACF possessed a richer array of strongly polar oxygen/nitrogen-containing functional groups(primarily phenolic hydroxyl and lactone groups),a larger specific surface are1,and a more developed micropore structure.The adsorption capacities of ethanol for O-ACF and N-ACF were 4.110 mmol/g and 1.698 mmol/g,respectively,which were 11.3 times and 4.7 times those of unmodified ACF.This was a significant improvement over our previous work(0.363 mmol/g).The improvement of adsorption capacity for the N-ACF was mainly due to the higher specific surface are1,greater number of micropores(more adsorption sites)and abundant existence of defects,whereas,for O-ACF,the improvement mainly relied on the abundant presence of oxygen-containing functional groups on the surface.However,water had a negative effect on the adsorption of ethanol for the modified ACF due to competitive adsorption and the disappearance of capillary condensation.It was further revealed that the adsorption process of ethanol and water was quite different.It obeyed the linear driving force(LDF)model for ethanol adsorption,however,the intraparticle diffusion(IPD)model for water adsorption.
基金supported by the National Natural Science Foundation of China(No.52200049)the China Postdoctoral Science Foundation(No.2022TQ0089)the Heilongjiang Province Postdoctoral Science Foundation(No.LBHZ22181).
文摘Humic acid(HA),as a represent of natural organic matter widely existing in water body,dose harm to water quality and human health;however,it was commonly treated as an environmental background substance while not targeted contaminant in advanced oxidation processes(AOPs).Herein,we investigated the removal of HA in the alkali-activated biochar(KBC)/peroxymonosulfate(PMS)system.The modification of the original biochar(BC)resulted in an increased adsorption capacity and catalytic activity due to the introduction of more micropores,mesopores,and oxygen-containing functional groups,particularly carbonyl groups.Mechanistic insights indicated that HA is primarily chemically adsorbed on the KBC surface,while singlet oxygen(^(1)O_(2))produced by the PMS decomposition served as the major reactive species for the degradation of HA.An underlying synergistic adsorption and oxidation mechanism involving a local high concentration reaction region around the KBC interface was then proposed.This work not only provides a cost-effective solution for the elimination of HA but also advances our understanding of the nonradical oxidation at the biochar interface.
基金supported by the National Natural Science Foundation of China(No.52200187)Shenzhen Science and Technology Program(No.JCYJ20220530160411025)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2024A1515030273)the Provincial Natural Science Foundation of Hunan(No.2023JJ10012)the Provincial Natural Science Foundation of Hunan(No.2023JJ10012).
文摘P-arsanilic acid(AA)has received widespread attention because of its conversion to more toxic inorganic arsenic compounds(arsenate and arsenite)in the natural ecosystems.Its removal process and mechanisms with co-existence of microplastics remain unkown.In this study,biochar loaded with nano zero-valent iron(nZVI)particles(ISBC)was prepared by using iron scrap obtained from a steel works and wood chips collected from a wood processing plant.The advanced oxidation system of sodium persulfate(PDS)activated by ISBC was applied for AA degradation and inorganic arsenic control in aqueous media.More than 99%of the AA was completely degraded by the ISBC/PDS system,and the As(III)on AA was almost completely oxidized to As(V)and finally removed by ISBC.HCO_(3)−inhibited the removal of AA by the ISBC/PDS system,while Cl^(−)had a dual effect that showing inhibition at low concentrations yet promotion at high concentrations.The effect of microplastics on the degradation of AA by the ISBC/PDS system was further investigated due to the potential for combined microplastic and organic arsenic contamination in rural/remote areas.Microplastics were found to have little effect on AA degradation in the ISBC/PDS system,while affect the transport of inorganic arsenic generated from AA degradation.Overall,this study provides new insights and methods for efficient removal of p-arsanilic acid from water with coexisting microplastics.
基金funded by the Ministry of Research,Technology,and Higher Education under Grant Number B/67/D.D3/KD.02.00/2019as part of the BPPDN(Beasiswa Pendidikan Pascasarjana Dalam Negeri—Domestic Postgraduate Education Scholarship)program.
文摘This study evaluates the effectiveness of microwave technology in producing activated carbon from lemongrass waste,an underutilized agricultural byproduct.Microwave-assisted production offers faster heating,lower energy consumption,and better process control compared to conventionalmethods.It also enhances pore development,resulting in larger,cleaner,and more uniform pores,making the activated carbon more effective for adsorption.The microwave-assisted process significantly accelerates production,reducing the required time to just 10 min at a power of 400 W.Activated carbon derived from lemongrass waste at 400 W exhibits a water absorption capacity of 7.88%,ash content of 5.51%,volatile matter of 6.96%,fixed carbon of 75.79%,and an iodine number of 790.97 g iodine/100 g.Scanning Electron Microscopy(SEM)analysis confirms the formation of larger,cleaner,and smoother pores,contributing to increased porosity and pore size.Additionally,Energy Dispersive X-ray(EDX)analysis identifies key elements in the lemongrass waste,with carbon being the dominant component at 75.57%.The Brunauer-Emmett-Teller(BET)surface area is measured at 818 m^(2)/g,with an average pore diameter of 1.91 nm,classifying the material as microporous.The activated carbon,meeting quality standards,is applied as an adsorbent in acid mine drainage(AMD)treatment,with varying mass concentrations introduced intowastewater samples.Adsorption tests confirmthat the microparticle carbon adsorption profile follows the Langmuir model,indicating a monolayer adsorption process.Furthermore,adsorption kineticswere analyzed over different time intervals,revealing that the process alignswith both pseudo-first-order(PFO)and pseudo-second-order(PSO)models,with all cases predominantly following the PFO rate equation.
基金supported by Sichuan Environmental Protection Industry Group Co.,Ltd.,China(No.2021-CNSW-A01).
文摘Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving the solubility and bioavailability of WAS organic matter.Considering the energy consumption and chemical cost,this paper used low-dose nanozero-valent iron (NZVI) coupled with low-intensity ultrasonication (US) to pretreat WAS,and explored the effects of different treatment sequences on the fragmentation of WAS flocs particles,the dissolution of organic matter,and the subsequent biofermentation conversion process.The results showed low-dose NZVI synchronized with low-intensity US (NZVIUS)worked best for WAS anaerobic fermentation.Compared with 2062 mg/L in control group,soluble chemical oxygen demand (SCOD) after NZVIUS treatment reached up to 2786 mg/L during the fermentation cycle,and the initial release rate of SCOD increased by 69%.The VFAs production was elevated from 1522 to 1940 mg COD/L.NZVIUS pretreatment promoted the solubilization of attached organic matter,manifested by the fragmentation of WAS flocs and cell lysis.At the same time,proteins and carbohydrates in the extracellular polymeric substances (EPS) had different types of migration and transformation,and transfer of EPS can contribute 35.6% to SCOD.Moreover,adding NZVI promoted PO_(4)^(3-)-P recovery in the fermentation supernatant by 22.3% more than in day 4 control.This study demonstrated that the NZVIUS pretreatment method can effectively improve the production of VFAs by WAS anaerobic fermentation,meeting the practical needs of wastewater plants.
基金The Sherman Fairchild Foundation Undergraduate Research GrantThe National Science Foundation Award#1912400:HBCU-UP Implementation Project:Improving Minority Participation and Completion through STEM at Dillard University(IMPACTS@DU Ⅱ)Dillard University Endowed Professorship,funds。
文摘Abstract:In today’s economy,determining accessible and affordable techniques to remove Heavy Metals(HMs)from wastewater is crucial.Activated carbon is highly effective in adsorbing HMs due to its large surface area and porous structure.It works by attracting and binding HM ions to its surface.Okoubaka is known for its medicinal properties and some studies suggest it has detoxifying effects.However,its specific role in HM removal would likely involve binding mechanisms like other plant-based materials.This study examines the efficiency of activated charcoal,charred versus uncharred Okoubaka plant materials,eggshells and oxalic acid to remove HMs like copper,lead,and zinc from contaminated water.
基金financially supported by National Natural Science Foundation of China(No.22207113 to J.Zhang)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110588to J.Zhang)Natural Science Foundation of Shanghai Municipality(No.22ZR1474000 to L.Wen)。
文摘Uronic acids are prevalent components of crucial glycoconjugates,pivotal in various biological processes.In nature,NDP-uronic acids,the nucleosides-activated uronic acids,serve as glycosylation donors catalyzed by uronosyltransferases(UATs)to construct glycans containing uronic acids.Despite their biological importance,the synthesis of naturally occurring NDP-uronic acids on a large scale remains challenging.Here,we developed an oxidation reaction insertion strategy for the efficient synthesis of NDP-uronic acids,and 11 NDP-uronic acids were successfully prepared in good yield and on a large scale.The prepared NDP-uronic acids can be used to explore new uronosyltransferases and synthesize uronic acids containing carbohydrates for fundamental research.
基金supported by the National Natural Science Foundation of China(21176236)~~
文摘Pt/activated carbon （Pt/AC） catalyst combined with base works efficiently for lactic acid production from glycerol under mild conditions. Base type （LiOH, NaOH, KOH, or Ba（OH）2） and base/glycerol molar ratio significantly affected the catalytic performance. The corresponding lactic acid selectivity was in the order of LiOH〉NaOH〉KOH〉Ba（OH）2. An increase in LiOH/glycerol molar ratio ele‐vated the glycerol conversion and lactic acid selectivity to some degree, but excess LiOH inhibited the transformation of glycerol to lactic acid. In the presence of Pt/AC catalyst, the maximum selec‐tivity of lactic acid was 69.3% at a glycerol conversion of 100% after 6 h at 90 °C, with a Li‐OH/glycerol molar ratio of 1.5. The Pt/AC catalyst was recycled five times and was found to exhibit slightly decreased glycerol conversion and stable lactic acid selectivity. In addition, the experimental results indicated that reaction intermediate dihydroxyacetone was more favorable as the starting reagent for lactic acid formation than glyceraldehyde. However, the Pt/AC catalyst had adverse effects on the intermediate transformation to lactic acid, because it favored the catalytic oxidation of them to glyceric acid.
基金supported by the National Natural Science Foundation of China(21373185,41672033,21506188,21404090)the Open Project Programs of Engineering Research Center of Non-metallic Minerals of Zhejiang Province(ZD2015k07)+2 种基金of State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology(GCTKF2014006)of Key Laboratory of High Efficient Processing of Bamboo of Zhejiang Province(2016)of State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology(CRE-2016-C-303)~~
文摘The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts were prepared by an impregnation method using H3PO4‐activated Mt(Mt‐P)as the support.The catalysts were characterized using powder X‐ray diffraction,Fourier‐transform infrared spectroscopy,N2adsorption‐desorption,diffuse reflectance ultraviolet‐visible spectroscopy,temperature‐programmed desorption of NH3,and thermogravimetric analysis.The acid activation of Mt and WOx loaded on Mt‐P affected the strength and number of acid sites arising from H+exchange,the leaching of octahedral Al3+cations from Mt octahedral sheets,and the types of WOx(2.7≤x≤3)species(i.e.,isolated WO4/WO6‐containing clusters,two‐dimensional[WO6]polytungstates,or three‐dimensional WO3crystals).The strong acid sites were weakened,and the weak and medium acid sites were strengthened when the W loading on Mt‐P was12wt%(12%W/Mt‐P).The12%W/Mt‐P catalyst showed the highest catalytic activity.It gave a glycerol conversion of89.6%and an acrolein selectivity of81.8%at320°C.Coke deposition on the surface of the catalyst led to deactivation.
基金Project(50802034) supported by the National Natural Science Foundation of ChinaProject(11A093) supported by the Key Project Foundation by the Education Department of Hunan Province,China
文摘TiO2-coated activated carbon surface （TAs） composites were prepared by a sol-gel method with supercritical pretreatment. The photocatalytic degradation of acid yellow （AY） was investigated under UV radiation to estimate activity of catalysts and determine the kinetics. And the effects of parameters including the initial concentration of AY, light intensity and TiO2 content in catalysts were examined. The results indicate that TAs has a higher efficiency in decomposition of AY than P25, pure TiO2 particles as well as the mixture of TiO2 powder and active carbon. The photocatalytic degradation rate is found to follow the pseudo-first order kinetics with respect to the AY concentration. The new kinetic model fairly resembles the classic Langmuir-Hinshelwood equation, and the rate constant is proportional to the square root of the light intensity in a wide range. However, its absorption performance depends on the surface areas of catalysts. The model fits quite well with the experimental data and elucidates phenomena about the effects of the TiO2 content in TAs on the degradation rate.
基金This work was supported by the National Natural Science Foundation of China （No.20502017, No.20872102, and No.21021001）, the Program for Changjiang Scholars and Innovative Research Team in University （No.IRT0846）, and the characterization of the catalyst from Analytic and Testing Center of Sichuan University are greatly appreciated.
文摘Commercially available coal-based activated carbon was treated by nitric acid with different concentrations and the resultant samples were used as catalysts for the direct hydroxylation of benzene to phenol in acetonitrile. Boehm titration, X-ray photoelectron spectroscopy, scanning electron microscope coupled with an energy dispersive X-ray microanalyzer, and Brunauer-Emmett-Teller method were used to characterize the samples. The number of carboxyl groups on the surface was found to be the main factor affecting the catalytic activity. An optimum catalytic performance with a yield of 15.7% and a selectivity of 87.2% to phenol was obtained.
