A Brønsted acid-catalyzed peroxidation of 3-hydroxyisoindolinones with hydroperoxides has been established for the first time,which constructsα-amino peroxides bearing a tetrasubstituted stereocenter in good to ...A Brønsted acid-catalyzed peroxidation of 3-hydroxyisoindolinones with hydroperoxides has been established for the first time,which constructsα-amino peroxides bearing a tetrasubstituted stereocenter in good to high yields and enantioselectivities.The transformation uses of environmentally benign solvents,and features operational simplicity,and high atom economy.The synthetic utility was demonstrated with the gram-scale reactions and further transformations of the products.Notably,preliminary bioactivity studies reveal that these valuableα-amino peroxides show potential anticancer activity.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
The two-electron electrochemical oxygen reduction reaction(ORR)affords an appealing alternative for on-site production of hydrogen peroxide(H_(2)O_(2)),which can fulfill the demands of various applications even at low...The two-electron electrochemical oxygen reduction reaction(ORR)affords an appealing alternative for on-site production of hydrogen peroxide(H_(2)O_(2)),which can fulfill the demands of various applications even at low concentrations.Under neutral or near-neutral conditions,the electrolyte environment capable of electrochemically synthesizing H_(2)O_(2) exhibits diversity and holds vast potential for practical applications;however,the electrocatalytic performance is limited without desirable electrode materials.In this contribution,methoxylated nickel hydroxides were proposed for high-performance on-site H_(2)O_(2) electrosynthesis in different potassium fertilizer solutions.The methoxylation compared to pristine Ni(OH)_(2) was demonstrated to optimize the electronic structure with favorable adsorption of reaction intermediates,obviously enhancing the activity and selectivity.In 0.10 M K_(2)SO_(4) solution,H_(2)O_(2) production ranged from 28.1 to 153.6 mg h^(-1) cm^(-2) at current densities of-50 to-250 mA cm^(-2),accompanied by Faradaic efficiency values exceeding 88.0%.An integrated system was devised by combining fertilization,disinfection,and irrigation through the coupling of two-electron ORR with agricultural irrigation,utilizing nutrient solutions as the electrolyte for on-site H_(2)O_(2) electrosynthesis.These findings afford a promising avenue for the practical application of 2e-ORR in neutral environments.展开更多
Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for ...Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for 2e^(-)ORR in alkaline media.However,it is challenged by insufficient activity and selectiv-ity of the catalysts in acidic electrolytes.Herein,we report sulfur-poisoned PtNi/C catalysts(PtNiSx/C)that could regulate ORR from the 4e^(-)to 2e^(-)pathway.The identified PtNiS0.6/C offers high activity in terms of onset potential of∼0.69 V(vs.RHE)and∼80%selectivity.The mass activity is also compara-ble and outperforms representative Pt-based precious and transition-metal-based catalysts.In addition,it is interestingly found that the Faradaic efficiency further increased to 95%during the long-term elec-trolysis test due to Ni atom surface migration.The electrochemical production of the H_(2)O_(2)system was applied to the electro-Fenton process,which has realized the effective degradation of organic pollutants.This work offers a strategy by sulfur poisoning PtNi/C catalyst to realize Pt-based 2e^(-)ORR active catalysts to electrolysis of H_(2)O_(2)in acidic media.展开更多
Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face si...Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face significant challenges in terms of energy consumption and environmental impact.As a sustainable alternative,photocatalytic H_(2)O_(2) production,driven by solar energy,has emerged as a promising approach.This review discusses the key advancements in photocatalytic H_(2)O_(2) synthesis,focusing on overcoming challenges such as charge recombination,selectivity for the two-electron oxygen reduction reaction(2e^(-)ORR),and catalyst stability.Recent innovations in photocatalyst design,including high-entropy materials,single-atom catalysts,and covalent organic frameworks(COFs),have significantly enhanced efficiency and stability.Furthermore,novel strategies for optimizing charge separation,light harvesting,and mass transfer are explored.The integration of artificial intelligence and bioinspired systems holds potential for accelerating progress in this field.This review provides a comprehensive overview of current challenges and cutting-edge solutions,offering valuable insights for the development of scalable,decentralized H_(2)O_(2) production systems that contribute to a more sustainable future.展开更多
BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)i...BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.展开更多
A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water co...A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water column but their impact on attached communities is unknown. The experimental design included a total of 4 treatments: control (no chemicals;3 replicates);hydrogen peroxide (3 replicates);glucose alone (3 different concentrations [no replicates]);and additive glucose (3 replicates). After 34 days, mean values of chlorophyll a were lower in all experimental treatments compared to the control;mean AFDM values were lower in all treatments except the unreplicated high glucose alone treatment. In contrast, mean autotrophic index values (AFDM/chlorophyll a) were greater in all treatments compared to the control, indicating heterotrophs were more resistant to the chemical treatments than autotrophs. Periphyton community biodiversity was much lower in the additive glucose and moderate glucose alone treatments than the hydrogen peroxide and control treatments. The relative abundance of the bacteria Asticcacaulis and Sphingorhabdus responded positively to the glucose treatments, whereas relative abundance of Nevskia and Caenimonas declined in both the hydrogen peroxide and glucose treatments. In terms of relative abundance, no cyanobacteria taxa were detected among the top 20 taxa. We conclude that the autotrophic component of periphyton communities is especially vulnerable to hydrogen peroxide and glucose treatments, and that any management strategy employing these chemicals should be aware of this potential impact.展开更多
Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its...Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its industrial maturity and high yield,suffers from high energy consumption,carbon emissions,safety risks,and reliance on precious metals[2].Despite ongoing optimizations,a more sustainable alternative is urgently needed.The direct synthesis of hydrogen peroxide from water and oxygen has long been considered as an ideal alternative due to its theoretical 100%atom efficiency and environmental sustainability.展开更多
Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggre...Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.展开更多
Hydrogen peroxide(H_(2)O_(2))is a versatile compound with widespread applications in various industries.In addition,it has attracted inte rest as a potential energy carrier due to its high energy density and ability t...Hydrogen peroxide(H_(2)O_(2))is a versatile compound with widespread applications in various industries.In addition,it has attracted inte rest as a potential energy carrier due to its high energy density and ability to release oxygen upon decomposition.The development of photocatalytic technology has enabled sustainable production of H_(2)O_(2).Various structural materials,including organic molecules,polymers,and metal coordination compounds,have been synthesized for investigating photocatalytic H_(2)O_(2)production.Rare earth materials,in particular,are of interest due to their adjustable porosity and controllable metal active sites,making them valuable for research in this field.These materials have excellent photoelectric properties,making them promise for the photocatalytic synthesis of H_(2)O_(2).Despite limited reports on systematic reviews of photocatalytic H_(2)O_(2)production using rare earth materials,this study introduces the principles and advancements in this area.It reviews different methods of photocatalytic synthesis of H_(2)O_(2),focusing on rare earth elements.Through comprehensive analysis and systematic studies in the existing literature,a deeper understanding of enhanced photocatalytic performance has been achieved.This research not only contributes to advancing fundamental knowledge but also provides a solid foundation for practical applications.展开更多
Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive com...Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive complex operations and inherent safety risks from centralized production.The direct synthesis route from H_(2) coupled with O_(2) presents a promising alternative,but remains constrained by the safety requirement and the reaction control demand.This article systematically reviews breakthroughs in non-hydrogen catalytic systems for in situ synthesis of H_(2)O_(2).Through elucidating the mechanism of two-electron oxygen reduction pathways,renewable hydrogen substitutes with enhanced safety including CO,HCOOH,glucose and alcohols have been highlighted.Their efficient conversion of O_(2) to H_(2)O_(2) and the integration with sustainable processes such as selective oxidation are also discussed.It is expected to provide fundamental insights into the synergistic mechanism in heterogeneous catalysis and offer a new viewpoint for developing a decentralized H_(2)O_(2) synthesis system for practical applications,moving toward a greener and more economical H_(2)O_(2) production approach.展开更多
This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and report...This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and reports encouraging clinical outcomes with reducing agents,several methodological and clinical considera-tions require discussion.We examine three key aspects:The selective evidence synthesis approach;the need for rigorous clinical validation of proposed thera-pies;and the integration of this novel hypothesis with established inflammatory bowel disease pathogenesis.Given the complexity of UC,future therapeutic ad-vances may require collaborative approaches that integrate redox-based mecha-nisms into existing evidence-based frameworks rather than replacing current paradigms.展开更多
The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great...The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great challenges to promote two-electron O_(2)reduction and water oxidation.Herein,we present the well-dispersed graphitic carbon nitride quantum dots decorated with cyano groups(Na-CNQD and K-CNQD)by thermal polymerization of melamine in the presence of metal fluoride.The quantum confinement and edge effect have endowed the photocatalysts with rich active sites,wide light absorption range and the inhibited charge recombination.The cyano moieties function as O_(2)reduction centers to accept the photogenerated electrons and facilitate their rapid transfer to O_(2)molecules.This process enables the selective two-electron reduction of O_(2),leading to the production of H_(2)O_(2).Concurrently,the valence band holes on the heptazine moiety oxidize water into H_(2)O_(2).These synergistic effects promote photocatalytic H_(2)O_(2)production from O_(2)and H_(2)O without the need for additional photosensitizers,organic scavengers and co-catalysts.In contrast,pristine carbon nitride nanosheets remain inactive under the same conditions.This study offers new strategies for rational design of carbon-based materials for solar-to-chemical energy conversion.展开更多
Photocatalytic production of hydrogen peroxide(H_(2)O_(2))presents a promising strategy for environmental remediation and energy production.However,achieving clean and efficient H_(2)O_(2) production under ambient con...Photocatalytic production of hydrogen peroxide(H_(2)O_(2))presents a promising strategy for environmental remediation and energy production.However,achieving clean and efficient H_(2)O_(2) production under ambient conditions without organic sacrificial agents remains challenging.Enhancing the low crystallinity of covalent organic frameworks(COFs)can promote the separation and transmission of photo-generated carriers,thereby boosting their photocatalytic performance.Herein,we introduce a novel synthetic approach by substituting traditional acetic acid catalysts with organic base catalysts to enhance the crystallinity of β-ketoenamine-linked COF,TpBD-COF.Compared to TpBD-COF-A synthesized using acetic acid catalysts,TpBD-COF-B,synthesized with organic base catalysts,exhibited advancements including increased absorption intensity in the visible spectrum,reduced photoluminescence intensity,enhanced photo-generated carrier separation performance,and a 2.1-fold increase in photocatalytic H_(2)O_(2) production.Under visible light irradiation,TpBDCOF-B achieved a photocatalytic H_(2)O_(2) production rate of 533μmol/h/g using only air and water,without the need for organic sacrificial agents.Furthermore,TpBD-COF-B also exhibited good performance in long-term catalytic production experiments,tests with actual water bodies,and cyclic usage experiments.This study offers a strategy for enhancing the crystallinity of COFs to improve their photocatalytic activity,with promising applications in clean energy production and environmental remediation.展开更多
Perovskite oxides have shown great potential application in fuel cells due to the unique crystal structures and tunable composition as well as effective capability toward the oxygen reduction reaction(ORR),whereas the...Perovskite oxides have shown great potential application in fuel cells due to the unique crystal structures and tunable composition as well as effective capability toward the oxygen reduction reaction(ORR),whereas the investigation on the electrocatalytic performance of perovskite oxides toward the two-electron ORR to H_(2)O_(2)production remains very limited.Herein,a facile synthetic method has been developed to prepare La_(2)Sn_(2)O_(7)@La-doped ZnSnO_(3)heterostructures comprising of amorphous La_(2)Sn_(2)O_(7)and crystalline La-doped ZnSnO_(3).The optimal La_(2)Sn_(2)O_(7)@Ladoped ZnSnO_(3)heterostructures catalyst exhibits a significantly improved two-electron ORR performance to H_(2)O_(2)production with onset potential of 0.77 V and large current density of 2.51 m A.cm^(-2)at 0.1 V compared to ZnSnO_(3)(0.75 V,1.80 m A.cm^(-2),0.11 m A) as well as maintains high H_(2)O_(2)selectivity of 80%,which has been theoretically demonstrated to be contributed to the synergistic effect of amorphous La_(2)Sn_(2)O_(7)and crystalline La-doped ZnSnO_(3).Moreover,high H_(2)O_(2)yield rate of 2.9 m M.h^(-1)at 0.1 V can be achieved with a superior turnover frequency(TOF) of3.31 × 10^(-2)s^(-1)compared to the ZnSnO_(3)catalyst(2.10 × 10^(-2)s^(-1)).This work reveals the great potential of perovskite oxide as promising candidates for the environmentally friendly synthesis of hydrogen peroxide.展开更多
Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo sy...Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo synthesis of H_(2)O_(2) via both oxygen reduction reaction(ORR)and water oxidation reaction(WOR).In this paper,bismuth yttrium oxyhalides Bi_(2)YO_(4)X(X=Cl,Br,or I)are demonstrated to afford sufficient driving forces to produce H_(2)O_(2) in the absence of sacrificial reagents.After modification with Pt and IrO_(2) as cocatalysts,which can selectively promote both ORR and WOR reactions on Bi_(2)YO_(4)Cl,the IrO_(2)-Pt/Bi_(2)YO_(4)Cl sample yields H_(2)O_(2) production activity of 647μmol L^(-1)h^(-1)with negligible decay in the long-term reaction using only H_(2)O and an air atmosphere as the electron donors and O_(2) source.Detailed characterizations reveal that the ORR reaction obeys a two-electron pathway.We present the first example of oxyhalides(Bi_(2)YO_(4)X)capable of efficient photocata lytic H_2O_(2) generation with record-breaking activity.展开更多
As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquin...As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquinone process,the electrosynthesis of H_(2)O_(2)through the two-electron oxygen reduction reaction(2e^(−)ORR)is an efficient,competitive,and promising avenue.Electrocatalysts and devices are two core factors in 2e^(−)ORR,but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear.To this end,this review adopts a multiscale perspective to summarize recent advancements in the design principles,catalytic mechanisms,and application prospects of 2e^(−)ORR catalysts,with a particular focus on the influence of pH conditions,aiming at providing guidance for the selective design of advanced 2e^(−)ORR catalysts for highly-efficient H_(2)O_(2)production.Moreover,in response to diverse on-site application demands,we elaborate on the evolution of H_(2)O_(2)electrosynthesis devices,from rotating ring-disk electrodes and H-type cells to diverse flow-type cells.We elaborate on their characteristics and shortcomings,which can be beneficial for their further upgrades and customized applications.These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.展开更多
Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally b...Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally been limited to the four-electron pathway because of strong*OOH intermediate adsorption.In this study,we synthesized electron-deficient Co9S8 nanocrystals with an increased number of Co^(3+)states compared to conventional Co9S8.This was achieved by incorporating a high density of surface ligands in small-sized Co9S8nanocrystals,which enabled the transition of the electrochemical reduction pathway from four-electron oxygen reduction reaction to two-electron oxygen reduction reaction by decreasing*OOH adsorption strength.As a result,the Co^(3+)-enriched Co9S8 nanocrystals exhibited a high onset potential of 0.64 V(vs RHE)for two-electron oxygen reduction reaction,achieving H_(2)O_(2) selectivity of 70-80%over the potential range from 0.05 to 0.6 V.Additionally,these nanocrystals demonstrated a stable H_(2)O_(2) electrosynthesis at a rate of459.12 mmol g^(-1) h^(-1) with a H_(2)O_(2) Faradaic efficiency over 90%under alkaline conditions.This study provides insights into nanoscale catalyst design for modulating electrochemical reactions.展开更多
H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts sh...H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts show great promise for electrocatalytic production of H_2O_(2),due to the ease of regulation of the carbon materials with regard to the pore structure,surface properties,and heteroatom doping.Biomass as the carbon precursor has the advantages of low cost,sustainable supply,and extensive availability.Conversion of biomass to functional carbon-based materials shows the attractive merits,such as low carbon emission in the life cycle and diversity of the obtained carbon materials due to the wide source of biomass feedstocks.In this article,a comprehensive review on the mechanisms and processes of electrochemical synthesis of H_2O_(2) by 2e^(-)ORR over carbon-based catalysts is provided.The potential biomass feedstock used for obtaining the carbon-based catalysts,and the strategies to prepare the catalysts by carbonization and heteroatom doping,as well as optimization of electrodes and design of electrolyzer,are discussed.It is recommended that future work focus on developing efficient methods to prepare the catalysts from low-cost biomass feedstock,understanding the mechanisms of 2e^(-)ORR over the catalysts,optimization of electrode materials loaded with biomass-derived catalysts,as well as development of electrolyzers for larger-scale applications.展开更多
Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine ...Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine waste crumb rubber(WCR)were treated and analyzed through multi-scale characterization and molecular simulation.Microstructure and chemical changes of WCR and AWCR were analyzed with scanning electron microscope(SEM),contact angle tests and Fourier transform infrared spectroscopy(FTIR).Compatibility was also indirectly evaluated through modified boiling tests and storage stability tests.Besides,molecular dynamics was used to explore the interaction between WCR/AWCR and bitumen.SEM,contact angle,and FTIR results showed bond breakage of C=C and C–C and increased polar groups like–OH and–COOH in AWCR,resulting in a rougher texture and higher surface energy.Compared with WCR,AWCR showed a lower bitumen stripping rate after boiling,and the binder with AWCR also had a lower softening point difference and segregation rate after storage.Molecular dynamics simulations further confirmed that AWCR has a closer solubility parameter and higher binding energy to bitumen than WCR,reflected in a relatively slower diffusion rate.This study provides comprehensive evidence for an eco-friendly method of WCR surface treatment for more efficient recycling of tire rubber in asphalt pavements.展开更多
基金supported by the National Natural Science Foundation of China(No.52173044)we thank Dr.Fengchao Wang(Instrumental Analysis and Research Center,Tianjin University of Traditional Chinese Medicine)for providing biological activity testing.
文摘A Brønsted acid-catalyzed peroxidation of 3-hydroxyisoindolinones with hydroperoxides has been established for the first time,which constructsα-amino peroxides bearing a tetrasubstituted stereocenter in good to high yields and enantioselectivities.The transformation uses of environmentally benign solvents,and features operational simplicity,and high atom economy.The synthetic utility was demonstrated with the gram-scale reactions and further transformations of the products.Notably,preliminary bioactivity studies reveal that these valuableα-amino peroxides show potential anticancer activity.
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.
基金the support from the National Natural Science Foundation of China(22478221)China Postdoctoral Science Foundation(2023M741920 and GZC20231259)+1 种基金Huaneng Group Science and Technology Research Project(HNKJ23-H71)Department of Chemical Engineering-iBHE Cooperation Joint Fund Project(DCE-iBHE-2025-3)。
文摘The two-electron electrochemical oxygen reduction reaction(ORR)affords an appealing alternative for on-site production of hydrogen peroxide(H_(2)O_(2)),which can fulfill the demands of various applications even at low concentrations.Under neutral or near-neutral conditions,the electrolyte environment capable of electrochemically synthesizing H_(2)O_(2) exhibits diversity and holds vast potential for practical applications;however,the electrocatalytic performance is limited without desirable electrode materials.In this contribution,methoxylated nickel hydroxides were proposed for high-performance on-site H_(2)O_(2) electrosynthesis in different potassium fertilizer solutions.The methoxylation compared to pristine Ni(OH)_(2) was demonstrated to optimize the electronic structure with favorable adsorption of reaction intermediates,obviously enhancing the activity and selectivity.In 0.10 M K_(2)SO_(4) solution,H_(2)O_(2) production ranged from 28.1 to 153.6 mg h^(-1) cm^(-2) at current densities of-50 to-250 mA cm^(-2),accompanied by Faradaic efficiency values exceeding 88.0%.An integrated system was devised by combining fertilization,disinfection,and irrigation through the coupling of two-electron ORR with agricultural irrigation,utilizing nutrient solutions as the electrolyte for on-site H_(2)O_(2) electrosynthesis.These findings afford a promising avenue for the practical application of 2e-ORR in neutral environments.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.21805052 and 22227804)the Guangdong Basic and Applied Basic Research Foundation(No.2023B1515020110)+4 种基金the Science and Technology Research Project of Guangzhou(Nos.202102020787 and 2023A03J0030)the De-partment of Science&Technology of Guangdong Province(No.2022A156)the Key Laboratory of Optoelectronic Materials and Sensors in Guangdong Provincial Universities(No.2023KSYS008)the Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.20225546)the College Student Innovation and Entrepreneurship Training Program of Guangzhou University(No.XJ202311078029).
文摘Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for 2e^(-)ORR in alkaline media.However,it is challenged by insufficient activity and selectiv-ity of the catalysts in acidic electrolytes.Herein,we report sulfur-poisoned PtNi/C catalysts(PtNiSx/C)that could regulate ORR from the 4e^(-)to 2e^(-)pathway.The identified PtNiS0.6/C offers high activity in terms of onset potential of∼0.69 V(vs.RHE)and∼80%selectivity.The mass activity is also compara-ble and outperforms representative Pt-based precious and transition-metal-based catalysts.In addition,it is interestingly found that the Faradaic efficiency further increased to 95%during the long-term elec-trolysis test due to Ni atom surface migration.The electrochemical production of the H_(2)O_(2)system was applied to the electro-Fenton process,which has realized the effective degradation of organic pollutants.This work offers a strategy by sulfur poisoning PtNi/C catalyst to realize Pt-based 2e^(-)ORR active catalysts to electrolysis of H_(2)O_(2)in acidic media.
基金financial support from the National Natural Science Foundation of China(No.22279143).
文摘Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face significant challenges in terms of energy consumption and environmental impact.As a sustainable alternative,photocatalytic H_(2)O_(2) production,driven by solar energy,has emerged as a promising approach.This review discusses the key advancements in photocatalytic H_(2)O_(2) synthesis,focusing on overcoming challenges such as charge recombination,selectivity for the two-electron oxygen reduction reaction(2e^(-)ORR),and catalyst stability.Recent innovations in photocatalyst design,including high-entropy materials,single-atom catalysts,and covalent organic frameworks(COFs),have significantly enhanced efficiency and stability.Furthermore,novel strategies for optimizing charge separation,light harvesting,and mass transfer are explored.The integration of artificial intelligence and bioinspired systems holds potential for accelerating progress in this field.This review provides a comprehensive overview of current challenges and cutting-edge solutions,offering valuable insights for the development of scalable,decentralized H_(2)O_(2) production systems that contribute to a more sustainable future.
基金Supported by Bozhou Key Research and Development Project,No.bzzc2020031.
文摘BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.
文摘A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water column but their impact on attached communities is unknown. The experimental design included a total of 4 treatments: control (no chemicals;3 replicates);hydrogen peroxide (3 replicates);glucose alone (3 different concentrations [no replicates]);and additive glucose (3 replicates). After 34 days, mean values of chlorophyll a were lower in all experimental treatments compared to the control;mean AFDM values were lower in all treatments except the unreplicated high glucose alone treatment. In contrast, mean autotrophic index values (AFDM/chlorophyll a) were greater in all treatments compared to the control, indicating heterotrophs were more resistant to the chemical treatments than autotrophs. Periphyton community biodiversity was much lower in the additive glucose and moderate glucose alone treatments than the hydrogen peroxide and control treatments. The relative abundance of the bacteria Asticcacaulis and Sphingorhabdus responded positively to the glucose treatments, whereas relative abundance of Nevskia and Caenimonas declined in both the hydrogen peroxide and glucose treatments. In terms of relative abundance, no cyanobacteria taxa were detected among the top 20 taxa. We conclude that the autotrophic component of periphyton communities is especially vulnerable to hydrogen peroxide and glucose treatments, and that any management strategy employing these chemicals should be aware of this potential impact.
文摘Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its industrial maturity and high yield,suffers from high energy consumption,carbon emissions,safety risks,and reliance on precious metals[2].Despite ongoing optimizations,a more sustainable alternative is urgently needed.The direct synthesis of hydrogen peroxide from water and oxygen has long been considered as an ideal alternative due to its theoretical 100%atom efficiency and environmental sustainability.
基金supported by the National Key Research and Development Program of China(No.2022YFC3203301)the Natural Science Foundation of China(No.41406098).
文摘Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.
基金Project supported by the National Natural Science Foundation of China(22205084,42307566)the China Postdoctoral Science Foundation(2023M741039,2023M742199)+1 种基金the Science and Technology Project of Henan Province(232102321035)the State Key Laboratory of Efficient Utilization for Low Grade Phosphate Rock and Its Associated Resources(WFKF(2023)013)。
文摘Hydrogen peroxide(H_(2)O_(2))is a versatile compound with widespread applications in various industries.In addition,it has attracted inte rest as a potential energy carrier due to its high energy density and ability to release oxygen upon decomposition.The development of photocatalytic technology has enabled sustainable production of H_(2)O_(2).Various structural materials,including organic molecules,polymers,and metal coordination compounds,have been synthesized for investigating photocatalytic H_(2)O_(2)production.Rare earth materials,in particular,are of interest due to their adjustable porosity and controllable metal active sites,making them valuable for research in this field.These materials have excellent photoelectric properties,making them promise for the photocatalytic synthesis of H_(2)O_(2).Despite limited reports on systematic reviews of photocatalytic H_(2)O_(2)production using rare earth materials,this study introduces the principles and advancements in this area.It reviews different methods of photocatalytic synthesis of H_(2)O_(2),focusing on rare earth elements.Through comprehensive analysis and systematic studies in the existing literature,a deeper understanding of enhanced photocatalytic performance has been achieved.This research not only contributes to advancing fundamental knowledge but also provides a solid foundation for practical applications.
基金the National Natural Science Foundation of China(22125202,92461312,U24A20487,22302091,92361201)Natural Science Foundation of Jiangsu Province(BK20220033)+1 种基金Programs for high-level entrepreneurial and innovative talents of Jiangsu ProvinceChina Postdoctoral Science Foundation(2024T170400,2022M721551).
文摘Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive complex operations and inherent safety risks from centralized production.The direct synthesis route from H_(2) coupled with O_(2) presents a promising alternative,but remains constrained by the safety requirement and the reaction control demand.This article systematically reviews breakthroughs in non-hydrogen catalytic systems for in situ synthesis of H_(2)O_(2).Through elucidating the mechanism of two-electron oxygen reduction pathways,renewable hydrogen substitutes with enhanced safety including CO,HCOOH,glucose and alcohols have been highlighted.Their efficient conversion of O_(2) to H_(2)O_(2) and the integration with sustainable processes such as selective oxidation are also discussed.It is expected to provide fundamental insights into the synergistic mechanism in heterogeneous catalysis and offer a new viewpoint for developing a decentralized H_(2)O_(2) synthesis system for practical applications,moving toward a greener and more economical H_(2)O_(2) production approach.
文摘This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and reports encouraging clinical outcomes with reducing agents,several methodological and clinical considera-tions require discussion.We examine three key aspects:The selective evidence synthesis approach;the need for rigorous clinical validation of proposed thera-pies;and the integration of this novel hypothesis with established inflammatory bowel disease pathogenesis.Given the complexity of UC,future therapeutic ad-vances may require collaborative approaches that integrate redox-based mecha-nisms into existing evidence-based frameworks rather than replacing current paradigms.
基金supported by the National Natural Science Foundation of China(22361024 and 22471055)Natural Science Foundation of Jiangxi Province(20232ACB203001)+1 种基金Natural Science Foundation of Hebei Province(B2024202021,B2022202039)S&T Program of Hebei(236Z4308G)。
文摘The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great challenges to promote two-electron O_(2)reduction and water oxidation.Herein,we present the well-dispersed graphitic carbon nitride quantum dots decorated with cyano groups(Na-CNQD and K-CNQD)by thermal polymerization of melamine in the presence of metal fluoride.The quantum confinement and edge effect have endowed the photocatalysts with rich active sites,wide light absorption range and the inhibited charge recombination.The cyano moieties function as O_(2)reduction centers to accept the photogenerated electrons and facilitate their rapid transfer to O_(2)molecules.This process enables the selective two-electron reduction of O_(2),leading to the production of H_(2)O_(2).Concurrently,the valence band holes on the heptazine moiety oxidize water into H_(2)O_(2).These synergistic effects promote photocatalytic H_(2)O_(2)production from O_(2)and H_(2)O without the need for additional photosensitizers,organic scavengers and co-catalysts.In contrast,pristine carbon nitride nanosheets remain inactive under the same conditions.This study offers new strategies for rational design of carbon-based materials for solar-to-chemical energy conversion.
基金jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750200)the National Key Research and Development Program of China(No.2023YFC3706600)the National Natural Science Foundation of China(Nos.22225605 and 22193051).
文摘Photocatalytic production of hydrogen peroxide(H_(2)O_(2))presents a promising strategy for environmental remediation and energy production.However,achieving clean and efficient H_(2)O_(2) production under ambient conditions without organic sacrificial agents remains challenging.Enhancing the low crystallinity of covalent organic frameworks(COFs)can promote the separation and transmission of photo-generated carriers,thereby boosting their photocatalytic performance.Herein,we introduce a novel synthetic approach by substituting traditional acetic acid catalysts with organic base catalysts to enhance the crystallinity of β-ketoenamine-linked COF,TpBD-COF.Compared to TpBD-COF-A synthesized using acetic acid catalysts,TpBD-COF-B,synthesized with organic base catalysts,exhibited advancements including increased absorption intensity in the visible spectrum,reduced photoluminescence intensity,enhanced photo-generated carrier separation performance,and a 2.1-fold increase in photocatalytic H_(2)O_(2) production.Under visible light irradiation,TpBDCOF-B achieved a photocatalytic H_(2)O_(2) production rate of 533μmol/h/g using only air and water,without the need for organic sacrificial agents.Furthermore,TpBD-COF-B also exhibited good performance in long-term catalytic production experiments,tests with actual water bodies,and cyclic usage experiments.This study offers a strategy for enhancing the crystallinity of COFs to improve their photocatalytic activity,with promising applications in clean energy production and environmental remediation.
基金financially supported by the National Natural Science Foundation of China (No.22372057)Yunnan Fundamental Research Projects (No.202301AT070059)+2 种基金the Natural Science Foundation of Hunan Province (No.2023JJ30121)the Natural Science Foundation of Changsha (No.KQ2208259)the Fundamental Research Funds for the Central Universities (No.202044011)。
文摘Perovskite oxides have shown great potential application in fuel cells due to the unique crystal structures and tunable composition as well as effective capability toward the oxygen reduction reaction(ORR),whereas the investigation on the electrocatalytic performance of perovskite oxides toward the two-electron ORR to H_(2)O_(2)production remains very limited.Herein,a facile synthetic method has been developed to prepare La_(2)Sn_(2)O_(7)@La-doped ZnSnO_(3)heterostructures comprising of amorphous La_(2)Sn_(2)O_(7)and crystalline La-doped ZnSnO_(3).The optimal La_(2)Sn_(2)O_(7)@Ladoped ZnSnO_(3)heterostructures catalyst exhibits a significantly improved two-electron ORR performance to H_(2)O_(2)production with onset potential of 0.77 V and large current density of 2.51 m A.cm^(-2)at 0.1 V compared to ZnSnO_(3)(0.75 V,1.80 m A.cm^(-2),0.11 m A) as well as maintains high H_(2)O_(2)selectivity of 80%,which has been theoretically demonstrated to be contributed to the synergistic effect of amorphous La_(2)Sn_(2)O_(7)and crystalline La-doped ZnSnO_(3).Moreover,high H_(2)O_(2)yield rate of 2.9 m M.h^(-1)at 0.1 V can be achieved with a superior turnover frequency(TOF) of3.31 × 10^(-2)s^(-1)compared to the ZnSnO_(3)catalyst(2.10 × 10^(-2)s^(-1)).This work reveals the great potential of perovskite oxide as promising candidates for the environmentally friendly synthesis of hydrogen peroxide.
基金supported by the National Natural Science Foundation of China(22479040,22279138)the Natural Science Foundation of Tianjin(24JCQNJC00360)+3 种基金Government Guide the Development of Local Science and Technology Special Funds(246Z3707G)Young Scientific and Technological Talents(Level Three)in Tianjin(QN20230343)Hebei Yanzhao Golden Platform Talent Gathering Plan Backbone Talent Project(HJYB202501)the Natural Science Foundation of Liaoning Province(2022-MS023)。
文摘Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo synthesis of H_(2)O_(2) via both oxygen reduction reaction(ORR)and water oxidation reaction(WOR).In this paper,bismuth yttrium oxyhalides Bi_(2)YO_(4)X(X=Cl,Br,or I)are demonstrated to afford sufficient driving forces to produce H_(2)O_(2) in the absence of sacrificial reagents.After modification with Pt and IrO_(2) as cocatalysts,which can selectively promote both ORR and WOR reactions on Bi_(2)YO_(4)Cl,the IrO_(2)-Pt/Bi_(2)YO_(4)Cl sample yields H_(2)O_(2) production activity of 647μmol L^(-1)h^(-1)with negligible decay in the long-term reaction using only H_(2)O and an air atmosphere as the electron donors and O_(2) source.Detailed characterizations reveal that the ORR reaction obeys a two-electron pathway.We present the first example of oxyhalides(Bi_(2)YO_(4)X)capable of efficient photocata lytic H_2O_(2) generation with record-breaking activity.
基金supported by the National Natural Science Foundation of China(Nos.22102073,22075147).
文摘As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquinone process,the electrosynthesis of H_(2)O_(2)through the two-electron oxygen reduction reaction(2e^(−)ORR)is an efficient,competitive,and promising avenue.Electrocatalysts and devices are two core factors in 2e^(−)ORR,but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear.To this end,this review adopts a multiscale perspective to summarize recent advancements in the design principles,catalytic mechanisms,and application prospects of 2e^(−)ORR catalysts,with a particular focus on the influence of pH conditions,aiming at providing guidance for the selective design of advanced 2e^(−)ORR catalysts for highly-efficient H_(2)O_(2)production.Moreover,in response to diverse on-site application demands,we elaborate on the evolution of H_(2)O_(2)electrosynthesis devices,from rotating ring-disk electrodes and H-type cells to diverse flow-type cells.We elaborate on their characteristics and shortcomings,which can be beneficial for their further upgrades and customized applications.These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(no.20224000000020)supported by the MSIT(Ministry of Science and ICT),Korea,under the ICAN(ICT Challenge and Advanced Network of HRD)support program(IITP-2024-RS-2024-00437186)supervised by the IITP(Institute for Information&Communications Technology Planning&Evaluation)。
文摘Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally been limited to the four-electron pathway because of strong*OOH intermediate adsorption.In this study,we synthesized electron-deficient Co9S8 nanocrystals with an increased number of Co^(3+)states compared to conventional Co9S8.This was achieved by incorporating a high density of surface ligands in small-sized Co9S8nanocrystals,which enabled the transition of the electrochemical reduction pathway from four-electron oxygen reduction reaction to two-electron oxygen reduction reaction by decreasing*OOH adsorption strength.As a result,the Co^(3+)-enriched Co9S8 nanocrystals exhibited a high onset potential of 0.64 V(vs RHE)for two-electron oxygen reduction reaction,achieving H_(2)O_(2) selectivity of 70-80%over the potential range from 0.05 to 0.6 V.Additionally,these nanocrystals demonstrated a stable H_(2)O_(2) electrosynthesis at a rate of459.12 mmol g^(-1) h^(-1) with a H_(2)O_(2) Faradaic efficiency over 90%under alkaline conditions.This study provides insights into nanoscale catalyst design for modulating electrochemical reactions.
基金supported by the National Natural Science Foundation of China(Nos.22478222,22178197,and U23A6005)the Dr.Jentai Yang Sustainable Environmental Protection and Eco-humanistic Education Fund(No.20253000027)which isadministered by the Overseas Chinese Environmental Engineers and Scientists Association。
文摘H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts show great promise for electrocatalytic production of H_2O_(2),due to the ease of regulation of the carbon materials with regard to the pore structure,surface properties,and heteroatom doping.Biomass as the carbon precursor has the advantages of low cost,sustainable supply,and extensive availability.Conversion of biomass to functional carbon-based materials shows the attractive merits,such as low carbon emission in the life cycle and diversity of the obtained carbon materials due to the wide source of biomass feedstocks.In this article,a comprehensive review on the mechanisms and processes of electrochemical synthesis of H_2O_(2) by 2e^(-)ORR over carbon-based catalysts is provided.The potential biomass feedstock used for obtaining the carbon-based catalysts,and the strategies to prepare the catalysts by carbonization and heteroatom doping,as well as optimization of electrodes and design of electrolyzer,are discussed.It is recommended that future work focus on developing efficient methods to prepare the catalysts from low-cost biomass feedstock,understanding the mechanisms of 2e^(-)ORR over the catalysts,optimization of electrode materials loaded with biomass-derived catalysts,as well as development of electrolyzers for larger-scale applications.
基金supported by the research project“Green-health-safety Nexus for New Urban Spaces-GreeNexUS”(HORIZON MSCA-2021 DN,Marie Sklodowska-Curie Actions)Grant Agreement No.101073437:research grant under the title"Impact Absorbing Pavements with Improved Accessibility Features(DC9-IAP)".
文摘Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine waste crumb rubber(WCR)were treated and analyzed through multi-scale characterization and molecular simulation.Microstructure and chemical changes of WCR and AWCR were analyzed with scanning electron microscope(SEM),contact angle tests and Fourier transform infrared spectroscopy(FTIR).Compatibility was also indirectly evaluated through modified boiling tests and storage stability tests.Besides,molecular dynamics was used to explore the interaction between WCR/AWCR and bitumen.SEM,contact angle,and FTIR results showed bond breakage of C=C and C–C and increased polar groups like–OH and–COOH in AWCR,resulting in a rougher texture and higher surface energy.Compared with WCR,AWCR showed a lower bitumen stripping rate after boiling,and the binder with AWCR also had a lower softening point difference and segregation rate after storage.Molecular dynamics simulations further confirmed that AWCR has a closer solubility parameter and higher binding energy to bitumen than WCR,reflected in a relatively slower diffusion rate.This study provides comprehensive evidence for an eco-friendly method of WCR surface treatment for more efficient recycling of tire rubber in asphalt pavements.
