Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate...Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.展开更多
Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD...Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.展开更多
BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithel...BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithelial cells has a causal role leading to infiltration of neutrophils into the colonic mucosa and subsequent development of UC.This evidence-based mechanism identifies hydrogen peroxide as a therapeutic target for reducing agents in the treatment of UC.CASE SUMMARY Presented is a 41-year-old female with a 26-year history of refractory UC.Having developed steroid dependence and never achieving complete remission on treatment by conventional and advanced therapies,she began treatment with oral R-dihydrolipoic acid(RDLA),a lipid-soluble reducing agent with intracellular site of action.Within a week,rectal bleeding ceased.She was asymptomatic for three years until a highly stressful experience,when she noticed blood in her stool.RDLA was discontinued,and she began treatment with oral sodium thiosulfate pentahydrate(STS),a reducing agent with extracellular site of action.After a week,rectal bleeding ceased,and she resumed oral RDLA and discontinued STS.To date,she remains asymptomatic with normal stool calprotectin while on RDLA.CONCLUSION STS and RDLA are reducing agents that serve as highly effective and safe therapy for the induction and maintenance of remission in UC,even in patients refractory or poorly controlled by conventional and advanced therapies.Should preliminary findings be validated by subsequent clinical trials,the use of reducing agents could potentially prevent thousands of colectomies and represent a paradigm shift in the treatment of UC.展开更多
The efficient and sustainable removal of refractory high ionization potential(high-IP)organic pollutants remains challenging due to their redox inertness and poor interfacial electron transfer.Herein,we report a suspe...The efficient and sustainable removal of refractory high ionization potential(high-IP)organic pollutants remains challenging due to their redox inertness and poor interfacial electron transfer.Herein,we report a suspended photo-Fenton membrane (2D-C_(3)N_(4)/Fe-N-C/GO) that circumvents these limitations via a self-sufficient oxidant generation pathway,enabling low-carbon abatement of high-IP pollutants.This multifunctional architecture couples the visible-light-driven production of hydrogen peroxide(H_(2)O_(2)) by two-dimensional carbon nitride(2D-C_(3)N_(4)) with the Fe-N-C mediated adsorption and activation of electron-deficient species via pyridinic N-Fe^(2+)/Fe^(3+) redox pairs.Under light irradiation,photogenerated electrons continuously regenerate Fe^(2+) from Fe^(3+),sustaining reactive oxygen species(·OH)production and promoting efficient oxidative mineralization.The system demonstrates robust long-term performance in both synthetic and real wastewater matrices,achieving superior degradation and chemical oxygen demand(COD)removal.Life cycle assessment(LCA)confirms its environmental superiority over conventional homogeneous Fenton processes,with markedly reduced carbon emissions and ecological impacts.This work offers a mechanistically insightful and practically viable platform for the green,efficient,and durable remediation of high-IP organic pollutants,providing conceptual guidance for next-generation catalytic wastewater treatment technologies.展开更多
基金supports from the National Natural Science Foundation of China(Nos.22478426 and 22278436)Young Elite Scientists Sponsorship Program by BAST(No.1101020370359)Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ009)。
文摘Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.
基金financially supported by the Science and Technology Project of PetroChina Company Limited,China(No.2022DJ6314)the National Natural Science Foundation of China(No.52173056)。
文摘Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.
文摘BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithelial cells has a causal role leading to infiltration of neutrophils into the colonic mucosa and subsequent development of UC.This evidence-based mechanism identifies hydrogen peroxide as a therapeutic target for reducing agents in the treatment of UC.CASE SUMMARY Presented is a 41-year-old female with a 26-year history of refractory UC.Having developed steroid dependence and never achieving complete remission on treatment by conventional and advanced therapies,she began treatment with oral R-dihydrolipoic acid(RDLA),a lipid-soluble reducing agent with intracellular site of action.Within a week,rectal bleeding ceased.She was asymptomatic for three years until a highly stressful experience,when she noticed blood in her stool.RDLA was discontinued,and she began treatment with oral sodium thiosulfate pentahydrate(STS),a reducing agent with extracellular site of action.After a week,rectal bleeding ceased,and she resumed oral RDLA and discontinued STS.To date,she remains asymptomatic with normal stool calprotectin while on RDLA.CONCLUSION STS and RDLA are reducing agents that serve as highly effective and safe therapy for the induction and maintenance of remission in UC,even in patients refractory or poorly controlled by conventional and advanced therapies.Should preliminary findings be validated by subsequent clinical trials,the use of reducing agents could potentially prevent thousands of colectomies and represent a paradigm shift in the treatment of UC.
基金supported by the National Natural Science Foundation of China(22325602,22521201,22176060,and 22406142)the"National Key R&D Program of China"(SQ2024YFA1211001)+3 种基金the Program of Shanghai Academic/Technology Research Leader(23XD1421000)Key Laboratory of Functional Inorganic Material Chemistry(Heilongjiang University)Ministry of Education(KIM-0-2025017)State Key Laboratory of Water Pollution Control and Green Resource Recycling Foundation(PCRRF250014).
文摘The efficient and sustainable removal of refractory high ionization potential(high-IP)organic pollutants remains challenging due to their redox inertness and poor interfacial electron transfer.Herein,we report a suspended photo-Fenton membrane (2D-C_(3)N_(4)/Fe-N-C/GO) that circumvents these limitations via a self-sufficient oxidant generation pathway,enabling low-carbon abatement of high-IP pollutants.This multifunctional architecture couples the visible-light-driven production of hydrogen peroxide(H_(2)O_(2)) by two-dimensional carbon nitride(2D-C_(3)N_(4)) with the Fe-N-C mediated adsorption and activation of electron-deficient species via pyridinic N-Fe^(2+)/Fe^(3+) redox pairs.Under light irradiation,photogenerated electrons continuously regenerate Fe^(2+) from Fe^(3+),sustaining reactive oxygen species(·OH)production and promoting efficient oxidative mineralization.The system demonstrates robust long-term performance in both synthetic and real wastewater matrices,achieving superior degradation and chemical oxygen demand(COD)removal.Life cycle assessment(LCA)confirms its environmental superiority over conventional homogeneous Fenton processes,with markedly reduced carbon emissions and ecological impacts.This work offers a mechanistically insightful and practically viable platform for the green,efficient,and durable remediation of high-IP organic pollutants,providing conceptual guidance for next-generation catalytic wastewater treatment technologies.
