Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was i...Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was initially adsorbed on the porous ATPs, and then the enriched MB was removed by the H2O2-assisted Fenton-like oxidation with the iron-containing ATP catalyst. Under optimal conditions, the ATP powder exhibits the maximum removal efficiency of 100% with negligible iron leaching(1.5 mg L^(-1)) and no sludge formation. Furthermore,polysulfone/ATP(PSF/ATP) pellets were fabricated through a water-induced phase separation process to construct a fixed-bed reactor(FBR) for continuous contaminant removal. For the first cycle, the maximum adsorption capacity was 15.5 L with an outlet MB concentration of1.973 mg L-1(< 2 mg L^(-1), GB4287-2012) using the PSF/ATP pellets containing 50.0 g of ATP powders, and the maximum Fenton-like oxidation capacity was 35.5 L with the outlet concentration of 0.831 mg L^(-1). After five cycles, the total treated volume of the MB solution was ca. 255 L, and the efficiency remained above 99%. After 10 h of continuous treatment towards practical resin industrial wastewater, the chemical oxygen demand(COD) removal efficiency was still measured at 83.05%, costing 0.398 $ m^(-3). These results demonstrate the practical applicability of iron-containing low-grade ATP clay for textile water treatment.展开更多
Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and re...Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.展开更多
A series of spinel fe rrites magnetic nanopa rticles NiFe2 O4 we re synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2 O4@SiO2 catalysts were obtained by the modification of NiF...A series of spinel fe rrites magnetic nanopa rticles NiFe2 O4 we re synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2 O4@SiO2 catalysts were obtained by the modification of NiFe2 O4 via micro emulsion method.XRD,VSM,FTIR,SEM,TEM,BET and XPS were carried to analyze the difference between the above two catalysts.NiFe2 O4@SiO2 catalyst exhibited the higher catalytic activity than NiFe2 O4 for the degradation of Rhodamine B owe to the outer Si02 layers surface,the more important is both of them showed the better catalytic performance when at neutral pH environment.展开更多
The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentr...The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentrations of citric acid and iron. Because of its iron containment, the Fenton-like reaction automatically took place with the added amount of H2O2. The decomposition rate was found in a sequence of： UV/HEOE/Fe（Ⅲ） 〉 UV/H2O2 〉 Fe（Ⅱ）/H2O2. Two H2O2 injection methods, single and multiple points, were evaluated. The multiple-point H2O2 injection was more efficient to decompose the citric acid. The decomposition of the synthetic citric acid and the real derusting citric acid wastewater was also compared. The 93% COD reduction of the derusting wastewater was achieved using the UV/HEOE/Fe（Ⅲ） treatment.展开更多
The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance ...The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance the reaction of Fe(Ⅲ)/H_(2)O_(2) for degradation of diverse organic pollutants.Electron paramagnetic resonance analysis and chemical quenching/capturing experiments demonstrate that hydroxyl radicals(·OH)are the primary reactive species in the BC/Fe(Ⅲ)/H_(2)O_(2) system.In situ electrochemical analysis indicates that BC remarkably boosts the Fe(Ⅲ)/Fe(Ⅱ)redox cycles,where the adsorbed Fe(Ⅲ)cations were transformed to more active Fe(Ⅲ)species with a higher oxidative potential to react with H_(2)O_(2) to produce Fe(Ⅱ).Thus,the recovery of Fe(Ⅱ)from Fe(Ⅲ)is facilitated over BC surface,which enhancesOH generation via Fenton reactions.Moreover,BC exhibits outstanding reusability and stability in successive cycles and avoids the secondary pollution caused by conventional organic and metalliferous promotors.Therefore,metal-free BC boosting Fe(Ⅲ)/H_(2)O_(2) oxidation of organics provides a green and advanced strategy for water decontamination.展开更多
During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra w...During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra was found to be different between the top layer and the bottom layer in this column. Based on the data from XPS spectra and DMPO-OH·signal by EPR spectra,it is shown that the formation of ferryl (IV) is the key step for the oxidation of MG. The ferryl (IV) species can oxidize MG,and its redox potential is about 0. 739 - 0. 803 V measured by cyclic voltammograms (CV) . The catalytic capability of ferryl (IV) species was also evaluated,and it is found that it can promote the decomposition of H2O2 more efficiently than ferric iron. The removal rate of MG mainly depends on the adsorption of catalyst. Both ferryl (IV) and HO·radicals are the reactive species in the system. The oxidation of HO·is only a small part of the overall removal rate. Based on the obtained results,a possible mechanism for a resin-supported Fenton-like oxidation reaction is proposed.展开更多
Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhi...Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhibited ultrafast oxidation towards chlorophenol(CP)via peroxymonosulfate(PMS)activa tion,which was almost one order of magnitudes than most of carbon-based catalysts.The DB-SiOC/PMS system also showed the high ability to resist the interference of environmental matrix.The radicals(^(·)OH and SO_(4)^(·–))exhibited a very small contribution to the CP oxidation while the electron transfer processe(ETP)played the major role in the DB-SiOC/PMS system.The electron shuttles from the electron-donating CP molecules to the adjacent DB-SiOC/PMS^(*)could be efficiently triggered via Si-O bonds as bridges,mak ing it possible for ultrafast oxidation of CP.In addition,the hollow-disc shaped DB-Si OC provided the biomorphic DE structures with abundant pores for enriching the PMS and pollutants,thus further ac celerating the oxidation reaction.This work provided a new routine for the fabrication of Si-O doped carbon-based catalysts with excellent Fenton-like catalytic activity,which would greatly promote thei application prospects in Fenton-like systems.展开更多
Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen pero...Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen peroxide concentrations, pH value of solution, temperature and the presence of inorganic ions (carbonate, nitrate, chloride) on oxidative decolorization of amaranth were investigated. Amaranth degradation by (Fe3+/H2O2) reagent was found to follow first order kinetic model. Under optimum condition, pH = 2.6 and [FeCl3] = 3.75 × 10-4 mol·dm-3, the amaranth in aqueous solution with an initial concentration of 5 × 10-5 mol·dm-3 was degraded by 95% within 6 minutes. Increasing temperature in the range of 298 - 308 K increases the rate of dye degradation. Thermodynamic constants, ΔH*, ΔS* and ΔG* were evaluated. The results implied that the oxidation process was favorable and endothermic.展开更多
Peroxymonosulfate(PMS)-based Fenton-like technologies have been increasingly employed in the upgrading of biomass,but they are commonly limited by the trade-off between conversion and selectivity due to the short life...Peroxymonosulfate(PMS)-based Fenton-like technologies have been increasingly employed in the upgrading of biomass,but they are commonly limited by the trade-off between conversion and selectivity due to the short lifetime of reactive oxygen species(ROS)and uncontrollable oxidation pathways.Herein,we show that single-atom Co supported on carbon nitride enables the high-valent-oxo cobalt species(Co(IV)O)mediated oxidation of glucose into value-added products in acetonitrile.This photocatalytic Fenton-like system achieved an overall selectivity of gluconic acid,glucaric acid,arabinose,and formic acid up to 90.3%at glucose conversion of 69.6%,outperforming most of previously reported catalytic systems.The small amount(0.72 wt%)of single-atom Co could not only elevate the optical absorption and the efficiency of photo-generated carriers separation but also induce the efficient generation of Co(IV)O with reduced ROS to enable efficient and selective oxidation.These findings prove the great promise of high-valent metal-oxo species in biomass conversions.展开更多
Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerg...Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerging contaminants requires a substantial amount of hydroxyl radicals(HO˙),leading to excessive consumption of H_(2)O_(2).Through interfacial engineering of Fe-Zr bimetallic catalysts(FeZrO_(x)),this study demonstrates synergistic enhancement of phenolic pollutant removal at heterojunction interfaces while achieving an 80%reduction in H_(2)O_(2)dosage compared to traditional Fe_(2)O_(3)systems.The chemical states of Fe and Zr at the(104)/(111)heterojunction interface in FeZrO_(x)exhibit marked modifications relative to their monometallic Fe_(2)O_(3)and ZrO_(2)counterparts.The elevated charge density at interfacial Fe sites in FeZrO_(x)promotes HO˙generation,while optimized antibonding orbital composition below the Fermi level in bisphenol A adsorbed on Zr sites enhances hydrogen abstraction and subsequent polymerization.This Fe-Zr synergy at the(104)/(111)heterojunction concurrently suppresses HO˙diffusion losses and directs phenolic pollutant(e.g.,phenol and bisphenol A)polymerization within the reactive interface,thereby reducing H_(2)O_(2)consumption compared to monometallic systems.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical pr...The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.展开更多
To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electric...To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.展开更多
Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization w...Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization was explored to regulate multiple micro-structures for manufacture magnetic hydrochar(MHC)for Fenton-like degradation of tetracycline in aqueous solution.Diverse shapes of Fe_(3)O_(4) and nano zero-valent iron(nZVI)were doped with abundant oxygen containing groups and persistent free radicals(PFRs).Multiple catalysis sites including iron species,PFRs,oxygen containing groups,and graphite defects contributed to accelerate the Fenton-like degradation with synergistic effect.Notably,MHC achieved a tetracycline removal rate of 99% within 60 min at 50 mg/L,with a total organic carbon(TOC)removal rate of 35%.Furthermore,after four cycles of reuse,the degradation efficiency slightly decreased to 93%.This study highlights the potential of magnetic hydrochar with multiple catalytic sites in the effective and sustainable degradation of pollutants.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a...Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.展开更多
Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents ...Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.展开更多
Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs...Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs internal oxidation behavior and modulates iron oxide phase transition process.Sn addition significantly reduces the depth of grain boundaries oxidation and the area of internal oxidation,as well as retards the process of oxide scale transformation.Sn preferentially segregates at the iron oxide/substrate interface,forming a diffusion barrier that suppresses outward diffusion of alloying elements and inward oxygen transport.Concurrently,Sn enrichment at grain boundaries obstructs short-circuit oxygen diffusion pathways,significantly reducing the depth of oxidation at the grain boundaries.Furthermore,Sn segregation decreases the interfacial oxygen chemical potential and oxygen availability for selective oxidation reaction.The strategic incorporation of surface-active elements has emerged as a viable metallurgical approach to reduce internal oxidation in hot-rolled coils for AHSS applications.展开更多
A chemodivergent reaction is an appealing way to construct molecules with enriched structure diversity in a controlled manner. A plethora of methodologies were developed based on this concept, and transition metal-cat...A chemodivergent reaction is an appealing way to construct molecules with enriched structure diversity in a controlled manner. A plethora of methodologies were developed based on this concept, and transition metal-catalysis plays a central role among others catalysis systems own to its longstanding history. While a chemodivergent reaction based on organo-catalysis, especially photocatalysis, is rather limited as these concepts were only prevalent in the last two decades. With the ever-increasing importance of photocatalysis, a chemodivergent reaction based on such an activation pathway would be a meaningful direction. Herein, an efficient chemodivergent strategy for visible light photocatalysis is developed. By employing commercially available Rose Bengal as a photocatalyst, naturally occurring Viridicatin and its derivatives can be transformed into three different types of products through switchable single electron transfer (SET) or energy transfer (EnT) processes. Mechanistic studies have revealed that the oxygen as a reactive center, rather than carbon, is favored, which accounts for the first example of a C–O homo-dimerization product.展开更多
基金supported by Gansu Cuihua Technology Co.,Ltd.(H2020292)Science and Technology Planning of Baiyin City,Fundamental Research Funds for the Central Universities (buctrc202208)+2 种基金Engineering Research Center of Non-metallic Minerals of Zhejiang Province and the Beijing Engineering Center for Hierarchical Catalysts. Central Government Guiding Funds for Local Science and Technology Development (2022ZY015)Nanjiang Technology Project(2023AB028)Open Laboratory of State Key Laboratory of Organic and Inorganic Composites (oic-202301006)。
文摘Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was initially adsorbed on the porous ATPs, and then the enriched MB was removed by the H2O2-assisted Fenton-like oxidation with the iron-containing ATP catalyst. Under optimal conditions, the ATP powder exhibits the maximum removal efficiency of 100% with negligible iron leaching(1.5 mg L^(-1)) and no sludge formation. Furthermore,polysulfone/ATP(PSF/ATP) pellets were fabricated through a water-induced phase separation process to construct a fixed-bed reactor(FBR) for continuous contaminant removal. For the first cycle, the maximum adsorption capacity was 15.5 L with an outlet MB concentration of1.973 mg L-1(< 2 mg L^(-1), GB4287-2012) using the PSF/ATP pellets containing 50.0 g of ATP powders, and the maximum Fenton-like oxidation capacity was 35.5 L with the outlet concentration of 0.831 mg L^(-1). After five cycles, the total treated volume of the MB solution was ca. 255 L, and the efficiency remained above 99%. After 10 h of continuous treatment towards practical resin industrial wastewater, the chemical oxygen demand(COD) removal efficiency was still measured at 83.05%, costing 0.398 $ m^(-3). These results demonstrate the practical applicability of iron-containing low-grade ATP clay for textile water treatment.
基金supported by National Natural Science Fundation of China(Nos.52170086,22308194,U22A20423)Natural Science Foundation of Shandong Province(No.ZR2021ME013)+1 种基金Taishan Scholars Program of Shandong Province(No.tsqn202211012)Shandong Provincial Excellent Youth(No.ZR2022YQ47)。
文摘Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation,they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery.Therefore,the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts.In this work,an efficient catalyst was developed with Co-N_(x)configuration facilely reconstructed on the surface of Co_(3)O_(4)(Co-N_(x)/Co_(3)O_(4)),which exhibited superior catalytic activity.We further fixed the highly efficient Co-N_(x)/Co_(3)O_(4)onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability.Results indicated that the inorganic ceramic membrane(CM)can achieve high water flux of 710 L m-2h-1,and the similar water flux can be achieved by Co-N_(x)/Co_(3)O_(4)/CM even without the pressure extraction.We also employed the Co-N_(x)/Co_(3)O_(4)/CM system to the wastewater secondary effluent,and the pollutant in complicated secondary effluent could be highly removed by the Co-N_(x)/Co_(3)O_(4)/CM system.This paper provides a new point of view for the application of metal-based catalysts with M-N_(x)coordination in catalytic reaction device.
基金the financial support from the Fundamental Research Funds for the Central Universities(No. xjj2016045)
文摘A series of spinel fe rrites magnetic nanopa rticles NiFe2 O4 we re synthesized as the heterogeneous Fentonlike catalyst by hydrothermal method and then NiFe2 O4@SiO2 catalysts were obtained by the modification of NiFe2 O4 via micro emulsion method.XRD,VSM,FTIR,SEM,TEM,BET and XPS were carried to analyze the difference between the above two catalysts.NiFe2 O4@SiO2 catalyst exhibited the higher catalytic activity than NiFe2 O4 for the degradation of Rhodamine B owe to the outer Si02 layers surface,the more important is both of them showed the better catalytic performance when at neutral pH environment.
文摘The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentrations of citric acid and iron. Because of its iron containment, the Fenton-like reaction automatically took place with the added amount of H2O2. The decomposition rate was found in a sequence of： UV/HEOE/Fe（Ⅲ） 〉 UV/H2O2 〉 Fe（Ⅱ）/H2O2. Two H2O2 injection methods, single and multiple points, were evaluated. The multiple-point H2O2 injection was more efficient to decompose the citric acid. The decomposition of the synthetic citric acid and the real derusting citric acid wastewater was also compared. The 93% COD reduction of the derusting wastewater was achieved using the UV/HEOE/Fe（Ⅲ） treatment.
基金support to visit The University of Adelaide from the China Scholarship Council(No.201906240037).
文摘The sluggish kinetics of Fe(Ⅱ)recovery in Fenton/Fenton-like reactions significantly limits the oxidation efficiency.In this study,we for the first time use boron carbide(BC)as a green and stable promotor to enhance the reaction of Fe(Ⅲ)/H_(2)O_(2) for degradation of diverse organic pollutants.Electron paramagnetic resonance analysis and chemical quenching/capturing experiments demonstrate that hydroxyl radicals(·OH)are the primary reactive species in the BC/Fe(Ⅲ)/H_(2)O_(2) system.In situ electrochemical analysis indicates that BC remarkably boosts the Fe(Ⅲ)/Fe(Ⅱ)redox cycles,where the adsorbed Fe(Ⅲ)cations were transformed to more active Fe(Ⅲ)species with a higher oxidative potential to react with H_(2)O_(2) to produce Fe(Ⅱ).Thus,the recovery of Fe(Ⅱ)from Fe(Ⅲ)is facilitated over BC surface,which enhancesOH generation via Fenton reactions.Moreover,BC exhibits outstanding reusability and stability in successive cycles and avoids the secondary pollution caused by conventional organic and metalliferous promotors.Therefore,metal-free BC boosting Fe(Ⅲ)/H_(2)O_(2) oxidation of organics provides a green and advanced strategy for water decontamination.
基金Sponsored by the National High Technology Research and Development Program of China(863 Program) (Grant No.2006AA06Z306)the Natural Science Foundation of China under the Scheme of Innovation Group Fund
文摘During the oxidative degradation of nonbiodegradable Malachite green (MG) by means of H2O2 /FeIIIR (iron supported on ion-exchage resin) in a dynamic column,the binding energy of the Fe(2p3/2) region for XPS spectra was found to be different between the top layer and the bottom layer in this column. Based on the data from XPS spectra and DMPO-OH·signal by EPR spectra,it is shown that the formation of ferryl (IV) is the key step for the oxidation of MG. The ferryl (IV) species can oxidize MG,and its redox potential is about 0. 739 - 0. 803 V measured by cyclic voltammograms (CV) . The catalytic capability of ferryl (IV) species was also evaluated,and it is found that it can promote the decomposition of H2O2 more efficiently than ferric iron. The removal rate of MG mainly depends on the adsorption of catalyst. Both ferryl (IV) and HO·radicals are the reactive species in the system. The oxidation of HO·is only a small part of the overall removal rate. Based on the obtained results,a possible mechanism for a resin-supported Fenton-like oxidation reaction is proposed.
基金supported by National Natural Science Foundation of China(No.52170086)Shandong Provincial Excellent Youth(No.ZR2022YQ47)。
文摘Herein,a diatomite biomorphic Si-O doped carbon-based catalyst(DB-SiOC)was prepared using natura mineral diatomite as the silicon source and porous template.The results showed that the metal-free DB SiOC catalyst exhibited ultrafast oxidation towards chlorophenol(CP)via peroxymonosulfate(PMS)activa tion,which was almost one order of magnitudes than most of carbon-based catalysts.The DB-SiOC/PMS system also showed the high ability to resist the interference of environmental matrix.The radicals(^(·)OH and SO_(4)^(·–))exhibited a very small contribution to the CP oxidation while the electron transfer processe(ETP)played the major role in the DB-SiOC/PMS system.The electron shuttles from the electron-donating CP molecules to the adjacent DB-SiOC/PMS^(*)could be efficiently triggered via Si-O bonds as bridges,mak ing it possible for ultrafast oxidation of CP.In addition,the hollow-disc shaped DB-Si OC provided the biomorphic DE structures with abundant pores for enriching the PMS and pollutants,thus further ac celerating the oxidation reaction.This work provided a new routine for the fabrication of Si-O doped carbon-based catalysts with excellent Fenton-like catalytic activity,which would greatly promote thei application prospects in Fenton-like systems.
文摘Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen peroxide concentrations, pH value of solution, temperature and the presence of inorganic ions (carbonate, nitrate, chloride) on oxidative decolorization of amaranth were investigated. Amaranth degradation by (Fe3+/H2O2) reagent was found to follow first order kinetic model. Under optimum condition, pH = 2.6 and [FeCl3] = 3.75 × 10-4 mol·dm-3, the amaranth in aqueous solution with an initial concentration of 5 × 10-5 mol·dm-3 was degraded by 95% within 6 minutes. Increasing temperature in the range of 298 - 308 K increases the rate of dye degradation. Thermodynamic constants, ΔH*, ΔS* and ΔG* were evaluated. The results implied that the oxidation process was favorable and endothermic.
基金supported by the National Natural Science Foundation of China(22478202,22208169,U23A20125,22478203)China Postdoctoral Science Foundation(2022M721703).
文摘Peroxymonosulfate(PMS)-based Fenton-like technologies have been increasingly employed in the upgrading of biomass,but they are commonly limited by the trade-off between conversion and selectivity due to the short lifetime of reactive oxygen species(ROS)and uncontrollable oxidation pathways.Herein,we show that single-atom Co supported on carbon nitride enables the high-valent-oxo cobalt species(Co(IV)O)mediated oxidation of glucose into value-added products in acetonitrile.This photocatalytic Fenton-like system achieved an overall selectivity of gluconic acid,glucaric acid,arabinose,and formic acid up to 90.3%at glucose conversion of 69.6%,outperforming most of previously reported catalytic systems.The small amount(0.72 wt%)of single-atom Co could not only elevate the optical absorption and the efficiency of photo-generated carriers separation but also induce the efficient generation of Co(IV)O with reduced ROS to enable efficient and selective oxidation.These findings prove the great promise of high-valent metal-oxo species in biomass conversions.
基金supported by the National Natural Science Foundation of China(Grant Nos.22476187 and 22206173)the Natural Science Foundation of Henan Province(Grant No.252300421179)+1 种基金the Foundation of Henan Educational Committee(Grant No.25A610001)the Science and Technology Innovation Leading Talent Support Program of Henan Province(Grant No.254000510035).
文摘Fenton technology has garnered significant attention for the deep removal of low-concentration emerging contaminants due to its remarkable oxidation performance.However,the traditional mineralization process for emerging contaminants requires a substantial amount of hydroxyl radicals(HO˙),leading to excessive consumption of H_(2)O_(2).Through interfacial engineering of Fe-Zr bimetallic catalysts(FeZrO_(x)),this study demonstrates synergistic enhancement of phenolic pollutant removal at heterojunction interfaces while achieving an 80%reduction in H_(2)O_(2)dosage compared to traditional Fe_(2)O_(3)systems.The chemical states of Fe and Zr at the(104)/(111)heterojunction interface in FeZrO_(x)exhibit marked modifications relative to their monometallic Fe_(2)O_(3)and ZrO_(2)counterparts.The elevated charge density at interfacial Fe sites in FeZrO_(x)promotes HO˙generation,while optimized antibonding orbital composition below the Fermi level in bisphenol A adsorbed on Zr sites enhances hydrogen abstraction and subsequent polymerization.This Fe-Zr synergy at the(104)/(111)heterojunction concurrently suppresses HO˙diffusion losses and directs phenolic pollutant(e.g.,phenol and bisphenol A)polymerization within the reactive interface,thereby reducing H_(2)O_(2)consumption compared to monometallic systems.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
基金supported by the Key R&D Program of Shandong Province,China(No.2025CXGC 010412)the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(No.U21A2048).
文摘The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.
基金supported by Natural Science Foundation of Wuhan(2024040701010051)Natural Science Foundation of Hubei(2023AFB111)and National Natural Science Foundation of China(52401108).
文摘To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.
基金supported byHainan Provincial Natural Science Foundation of China(Nos.422RC600,519QN175)National Natural Science Foundation ofChina(Nos.52160018,21801053,52400206,52500209)High-Level Talent Program of Hainan Province(Nos.XJ2400008202,XJ2400011473).
文摘Oxidative magnetization has attracted great attention as an efficient strategy for modulating physiochemical properties of magnetic biochar.In this paper,a K_(2)FeO_(4)-involving hydrothermal oxidative magnetization was explored to regulate multiple micro-structures for manufacture magnetic hydrochar(MHC)for Fenton-like degradation of tetracycline in aqueous solution.Diverse shapes of Fe_(3)O_(4) and nano zero-valent iron(nZVI)were doped with abundant oxygen containing groups and persistent free radicals(PFRs).Multiple catalysis sites including iron species,PFRs,oxygen containing groups,and graphite defects contributed to accelerate the Fenton-like degradation with synergistic effect.Notably,MHC achieved a tetracycline removal rate of 99% within 60 min at 50 mg/L,with a total organic carbon(TOC)removal rate of 35%.Furthermore,after four cycles of reuse,the degradation efficiency slightly decreased to 93%.This study highlights the potential of magnetic hydrochar with multiple catalytic sites in the effective and sustainable degradation of pollutants.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金Supported by the National Natural Science Foundation of China Project(22362018)the Yunnan Fundamental Research Projects(202401AS070102)。
文摘Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.
基金support from the National Key Research and Development Program of China(Project No.2018YFB1502903).
文摘Perovskite oxides are highly promising catalysts for the combustion removal of volatile organic compounds(VOCs)due to their excellent stability,structural flexibility,and compositional versatility.This study presents a novel perovskite oxide that exhibits enhanced catalytic activity and superior durability for toluene combustion at reduced temperatures.This improvement is achieved by phosphorus doping at the B-site of LaCoO_(3-δ)(LC)perovskite oxide,followed by post-synthesis acid etching for a proper time.The resulting catalyst demonstrates increased specific surface area,higher total pore volume,and enhanced oxygen vacancy concentration both in the bulk and on the surface.Additionally,the activity of surface lattice oxygen species is significantly improved,leading to enhanced catalytic performance in toluene combustion.Notably,the optimized catalyst shows an exceptionally low activation energy(E_(a))of 49.3 kJ mol^(-1),with a T90 reduction of over 214℃compared to the phosphorus doped LC and 190℃compared to pristine LC.Phosphorus doping plays a main role in significantly improving the long-term durability,particularly in the presence of CO_(2)and H_(2)O,while acid etching boosts the catalytic activity.This work introduces a rational and innovative strategy for optimizing VOC oxidation by improving the structure and surface chemical states of perovskite catalysts.
基金National Key Research and Development Program of China(No.2023YFB3712400)Science and Technology Committee of Shanghai(Grant No.21ZR1423600)+2 种基金Central Government Guides the Development of Local Science and Technology Special Fund of China(Grant No.216Z1004G)and Baosteelsupport from Ningbo Yongjiang Talent Introduction Programme(2022A-023-C)Zhejiang Phenomenological Materials Technology Co.,Ltd.,China.Finally,the author Jin thanks Baosteel for permission to publish this work.
文摘Severe internal oxidation formed in advanced high-strength steels(AHSSs)during the hot-rolled coiling process compromises subsequent cold rolling and galvanizing processes.Herein,we report how Sn microalloying governs internal oxidation behavior and modulates iron oxide phase transition process.Sn addition significantly reduces the depth of grain boundaries oxidation and the area of internal oxidation,as well as retards the process of oxide scale transformation.Sn preferentially segregates at the iron oxide/substrate interface,forming a diffusion barrier that suppresses outward diffusion of alloying elements and inward oxygen transport.Concurrently,Sn enrichment at grain boundaries obstructs short-circuit oxygen diffusion pathways,significantly reducing the depth of oxidation at the grain boundaries.Furthermore,Sn segregation decreases the interfacial oxygen chemical potential and oxygen availability for selective oxidation reaction.The strategic incorporation of surface-active elements has emerged as a viable metallurgical approach to reduce internal oxidation in hot-rolled coils for AHSS applications.
基金the National Natural Science Foundation of China(No.22061012)the Excellent Young Talents Plan of Guizhou Medical University(No.[2023]105)+1 种基金the GMU Training Program of the National Natural Science Foundation of China(No.22NSFCP13)the support from National-Local Joint Engineering Research Center for Innovative&Generic Chemical Drug&Guizhou Province Innovation Base of Common Major Chronic Disease Pathogenesis and Drug Development and Application(No.[2021]4029).
文摘A chemodivergent reaction is an appealing way to construct molecules with enriched structure diversity in a controlled manner. A plethora of methodologies were developed based on this concept, and transition metal-catalysis plays a central role among others catalysis systems own to its longstanding history. While a chemodivergent reaction based on organo-catalysis, especially photocatalysis, is rather limited as these concepts were only prevalent in the last two decades. With the ever-increasing importance of photocatalysis, a chemodivergent reaction based on such an activation pathway would be a meaningful direction. Herein, an efficient chemodivergent strategy for visible light photocatalysis is developed. By employing commercially available Rose Bengal as a photocatalyst, naturally occurring Viridicatin and its derivatives can be transformed into three different types of products through switchable single electron transfer (SET) or energy transfer (EnT) processes. Mechanistic studies have revealed that the oxygen as a reactive center, rather than carbon, is favored, which accounts for the first example of a C–O homo-dimerization product.
