Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridiza...Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.展开更多
The electrochemical nitrogen reduction reaction(NRR)as an energy-efficient approach for ammonia synthesis is hampered by the low ammonia yield and ambiguous reaction mechanism.Herein,phosphorus-doped carbon nanotube(P...The electrochemical nitrogen reduction reaction(NRR)as an energy-efficient approach for ammonia synthesis is hampered by the low ammonia yield and ambiguous reaction mechanism.Herein,phosphorus-doped carbon nanotube(P-CNTs)is developed as an efficient metal-free electrocatalyst for NRR with a remarkable NH3 yield of 24.4μg·h^−1·mg^−1cat.and partial current density of 0.61 mA·cm^−2.Such superior activity is found to be from P doping and highly conjugated CNTs substrate.Experimental and theoretical investigations discover that the electron-deficient phosphorus sites with Lewis acidity should be genuine active sites and NRR on P-CNTs follows the distal pathway.These findings provide insightful understanding on NRR processes on P-CNTs,opening up opportunities for the rational design of highly-active cost-effective metal-free catalysts for electrochemical ammonia synthesis.展开更多
Electrocatalytic oxygen reduction via a two-electron pathway(2e^(-)-ORR)is a promising and eco-friendly route for producing hydrogen peroxide(H_(2)O_(2)).Single-atom catalysts(SACs)typically show excellent selectivity...Electrocatalytic oxygen reduction via a two-electron pathway(2e^(-)-ORR)is a promising and eco-friendly route for producing hydrogen peroxide(H_(2)O_(2)).Single-atom catalysts(SACs)typically show excellent selectivity towards 2e^(-)-ORR due to their unique electronic structures and geometrical configurations.The very low density of single-atom active centers,however,often leads to unsatisfactory H_(2)O_(2)yield rate,significantly inhibiting their practical feasibility.Addressing this,we herein introduce fluorine as a secondary doping element into conventional SACs,which does not directly coordinate with the singleatom metal centers but synergize with them in a remote manner.This strategy effectively activates the surrounding carbon atoms and converts them into highly active sites for 2e^(-)-ORR.Consequently,a record-high H_(2)O_(2)yield rate up to 27 mol g^(-1)h^(-1)has been achieved on the Mo–F–C catalyst,with high Faradaic efficiency of 90%.Density functional theory calculations further confirm the very kinetically facile 2e^(-)-ORR over these additional active sites and the superiority of Mo as the single-atom center to others.This strategy thus not only provides a high-performance electrocatalyst for 2e^(-)-ORR but also should shed light on new strategies to significantly increase the active centers number of SACs.展开更多
Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simpl...Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal method.The resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical reactors.In detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)electrolyzer.As a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to date.The theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.展开更多
The special electronic characteristics and high atom usage efficiency of metal-nitrogen-carbon(M-N-C)materials have made them extremely attractive for oxygen reduction reactions(ORRs).However,it is inevitable that hyd...The special electronic characteristics and high atom usage efficiency of metal-nitrogen-carbon(M-N-C)materials have made them extremely attractive for oxygen reduction reactions(ORRs).However,it is inevitable that hydrogen peroxide(H_(2)O_(2))will be formed via the two-electron pathway in ORRs.Herein,the Cu nanoparticles(NPs)have been encapsulated into Ni doped hollow mesoporous carbon spheres(Ni-HMCS)to reduce the generation of H_(2)O_(2)in ORR.Electrochemical tests confirm that the introduction of Cu NPs improves the ORR performance greatly.The obtained Cu/Ni-HMCS exhibits a half-wave potential of 0.82 V vs.reversible hydrogen electrode and a limited current density of 5.5 mA cm^(-2),which is comparable with the commercial Pt/C.Moreover,Cu/Ni-HMCS has been used in Zn-air battery,demonstrating a high power density of 161 mW cm^(-2)and a long-term recharge capability(50 h at 5 mA cm^(-2)).The theoretical calculation proposes a tandem catalysis pathway for Cu/Ni multi-sites catalysis,that is,H_(2)O_(2)released from the Ni-N_(4)and Cu-N_(4)sites migrates to the Cu(111)face,on which the captive H_(2)O_(2)is further reduced to H_(2)O.This work demonstrates an interesting tandem catalytic pathway of dual-metal multi-sites for ORR,which provides an insight into the development of effective fuel cell electrocatalysts.展开更多
In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction method.The size of Pt nanoparticles(NPs)is effectively controlled by d...In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction method.The size of Pt nanoparticles(NPs)is effectively controlled by doping with Mn and N.With the smallest average particle size of 1.7 nm,Mn-Pt/NKB demonstrates half-wave potentials of 0.890 and 0.688 V in the alkaline and neutral electrolytes,respectively,which are superior to those of commercial platinum on activated carbon(Pt/C).When applied as an air cathode in aluminum-air battery,it exhibits ultra-high power densities of 190(alkaline)and 26.2 mW·cm^(−2)(neutral).Moreover,the voltage remains stable after 5 h of discharge.The practical application performance of the Mn-Pt/NKB catalyst in an aluminum-air battery is better than that of commercial Pt/C.Furthermore,the oxygen reduction reaction(ORR)mechanism on surfaces with different particle sizes is analyzed using density functional theory.Oxygen cracking is the major pathway on the surface of the small particles with lower energy consumption of 0.5 eV,while water molecule cleavage is the major pathway on the surface of the large particles with higher energy consumption of 0.97 eV.The lower energy consumption of the oxygen cracking pathway further confirms the ORR mechanism for higher activity on small-sized surfaces.This study provides a direction for the rational design of Pt-based catalysts for ORR and sheds light on the commercial development of aluminum-air batteries.展开更多
Hydroxylamine(NH_(2)OH),a vital but unstable industrial feedstock,is presently prepared under harsh conditions that cause environmental and energy concerns.Here,we report an electrochemical method to prepare oximes,wh...Hydroxylamine(NH_(2)OH),a vital but unstable industrial feedstock,is presently prepared under harsh conditions that cause environmental and energy concerns.Here,we report an electrochemical method to prepare oximes,which serve as precursors for NH_(2)OH after facile hydrolysis.The carbon-supported amorphous Mn electrocatalyst delivers a current density of~100 mA cm^(-2) with a Faradaic efficiency of 40.92%and a yield rate of 0.251 mmol cm^(-2)h^(-1) for formaldoxime(CH_(2)NOH)generation by using nitrate and formaldehyde as reactants.Formaldoxime can be easily released to produce NH_(2)OH via hydrolysis.Impressively,this method exhibits an economic advantage over conventional manufacturing based on techno-economic analysis.A series of control experiments,in situ characterizations,and theoretical simulations unveil the reaction mechanism via the spontaneous reaction between an aldehyde and*NH_(2)OH intermediate derived from nitrate electroreduction.The high activity of Mn originates from its inhibitory effects on the further reduction of key*NH_(2)OH intermediate.This strategy opens a sustainable and green way for NH_(2)OH synthesis under mild conditions using renewable energy.展开更多
Methane(CH4)production from ruminants accounts for 16%of the global greenhouse gas emissions and represents 2%to 12%of feed energy.Mitigating CH_(4) production from ruminants is of great importance for sustainable dev...Methane(CH4)production from ruminants accounts for 16%of the global greenhouse gas emissions and represents 2%to 12%of feed energy.Mitigating CH_(4) production from ruminants is of great importance for sustainable development of the ruminant industry.H_(2) is the primary substrate for CH_(4) production in the processes of ruminal methanogenesis.Sulfate reducing bacteria are able to compete with methanogens for H_(2) in the rumen,and consequently inhibit the methanogenesis.Enhancing the ruminal sulfate reducing pathway is an important approach to mitigate CH_(4) emissions in ruminants.The review summarized the effects of sulfate and elemental S on ruminal methanogenesis,and clarified the related mechanisms through the impacts of sulfate and elemental S on major ruminal sulfate reducing bacteria.Enhancing the activities of the major ruminal sulfate reducing bacteria including Desulfovibrio,Desulfohalobium and Sulfolobus through dietary sulfate addition,elemental S and dried distillers grains with solubles can effectively decrease the ruminal CH_(4) emissions.Suitable levels of dietary addition with different S sources for reducing the ruminal CH_(4) production,as well as maintaining the performance and health of ruminants,need to be investigated in the future.展开更多
Statins,which are competitive inhibitors of 3-hydroxy-3-methyl-glutarylcoenzyme A reductase,reduce cholesterol blood levels and the risk of developing cardiovascular diseases and their related complications.In additio...Statins,which are competitive inhibitors of 3-hydroxy-3-methyl-glutarylcoenzyme A reductase,reduce cholesterol blood levels and the risk of developing cardiovascular diseases and their related complications.In addition to this main activity,statins show pleiotropic effects such as antioxidant,anti-inflammatory and antiproliferative properties,with applications in many pathologies.Based on their antiproliferative properties,in vitro and in vivo studies have investigated their effects on various types of cancer(i.e.,breast cancer,prostate cancer,colorectal cancer,ovarian cancer,lung cancer)with different genetic and molecular characteristics.Many positive results were obtained,but they were highly dependent on the physiochemical properties of the statins,their dose and treatment period.Combined therapies of statins and cytotoxic drugs have also been tested,and synergistic or additive effects were observed.Moreover,observational studies performed on patients who used statins for different pathologies,revealed that statins reduced the risk of developing various cancers,and improved the outcomes for cancer patients.Currently,there are many ongoing clinical trials aimed at exploring the potential of statins to lower the mortality and the disease-recurrence risk.All these results are the foundation of new treatment directions in cancer therapy.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.51478456 and 51178451)
文摘Anaerobic sludge from a sewage treatment plant was used to acclimatize microbial colonies capable of anaerobic oxidation of methane(AOM) coupled to sulfate reduction. Clone libraries and fluorescence in situ hybridization were used to investigate the microbial population.Sulfate-reducing bacteria(SRB)(e.g., Desulfotomaculum arcticum and Desulfobulbus propionicus)and anaerobic methanotrophic archaea(ANME)(e.g., Methanosaeta sp. and Methanolinea sp.)coexisted in the enrichment. The archaeal and bacterial cells were randomly or evenly distributed throughout the consortia. Accompanied by sulfate reduction, methane was oxidized anaerobically by the consortia of methane-oxidizing archaea and SRB. Moreover, CH_4 and SO_4^(2-) were consumed by methanotrophs and sulfate reducers with CO_2 and H_2S as products. The H_3CSH produced by methanotrophy was an intermediate product during the process. The methanotrophic enrichment was inoculated in a down-flow biofilter for the treatment of methane and H_2S from a landfill site. On average, 93.33% of H_2S and 10.71% of methane was successfully reduced in the biofilter. This study tries to provide effective method for the synergistic treatment of waste gas containing sulfur compounds and CH_4.
基金We acknowledge the financial supports are from the National Key Research and Development Program of China(No.2016YFB0101202)the National Natural Science Foundation of China(Nos.91645123,21773263).
文摘The electrochemical nitrogen reduction reaction(NRR)as an energy-efficient approach for ammonia synthesis is hampered by the low ammonia yield and ambiguous reaction mechanism.Herein,phosphorus-doped carbon nanotube(P-CNTs)is developed as an efficient metal-free electrocatalyst for NRR with a remarkable NH3 yield of 24.4μg·h^−1·mg^−1cat.and partial current density of 0.61 mA·cm^−2.Such superior activity is found to be from P doping and highly conjugated CNTs substrate.Experimental and theoretical investigations discover that the electron-deficient phosphorus sites with Lewis acidity should be genuine active sites and NRR on P-CNTs follows the distal pathway.These findings provide insightful understanding on NRR processes on P-CNTs,opening up opportunities for the rational design of highly-active cost-effective metal-free catalysts for electrochemical ammonia synthesis.
基金supported by the National Natural Science Foundation of China(Nos.22179093 and 21905202)。
文摘Electrocatalytic oxygen reduction via a two-electron pathway(2e^(-)-ORR)is a promising and eco-friendly route for producing hydrogen peroxide(H_(2)O_(2)).Single-atom catalysts(SACs)typically show excellent selectivity towards 2e^(-)-ORR due to their unique electronic structures and geometrical configurations.The very low density of single-atom active centers,however,often leads to unsatisfactory H_(2)O_(2)yield rate,significantly inhibiting their practical feasibility.Addressing this,we herein introduce fluorine as a secondary doping element into conventional SACs,which does not directly coordinate with the singleatom metal centers but synergize with them in a remote manner.This strategy effectively activates the surrounding carbon atoms and converts them into highly active sites for 2e^(-)-ORR.Consequently,a record-high H_(2)O_(2)yield rate up to 27 mol g^(-1)h^(-1)has been achieved on the Mo–F–C catalyst,with high Faradaic efficiency of 90%.Density functional theory calculations further confirm the very kinetically facile 2e^(-)-ORR over these additional active sites and the superiority of Mo as the single-atom center to others.This strategy thus not only provides a high-performance electrocatalyst for 2e^(-)-ORR but also should shed light on new strategies to significantly increase the active centers number of SACs.
基金the postdoctoral researcher funding project of Anhui Province(No.2022B585)the HFIPS Director’s Fund(No.YZJJ2023QN29)+1 种基金the National Natural Science Foundation of China(No.52172106)the Special Research Assistant Program,Chinese Academy of Sciences.
文摘Electrochemical nitrate reduction reaction(NO_(3)RR)is a promising means for generating the energy carrier ammonia.Herein,we report the synthesis of heterostructure copper-nickel phosphide electrocatalysts via a simple vapor-phase hydrothermal method.The resultant catalysts were evaluated for electrocatalytic nitrate reduction to ammonia(NH_(3))in three-type electrochemical reactors.In detail,the regulation mechanism of the heterogeneous Cu_(3)P-Ni_(2)P/CP-x for NO_(3)RR performance was systematically studied through the H-type cell,rotating disk electrode setup,and membrane-electrode-assemblies(MEA)electrolyzer.As a result,the Cu_(3)P-Ni_(2)P/CP-0.5 displays the practicability in an MEA system with an anion exchange membrane,affording the largest ammonia yield rate(RNH_(3))of 1.9 mmol·h^(−1)·cm^(−2),exceeding most of the electrocatalytic nitrate reduction electrocatalysts reported to date.The theoretical calculations and in-situ spectroscopy characterizations uncover that the formed heterointerface in Cu_(3)P-Ni_(2)P/CP is beneficial for promoting nitrate adsorption,activation,and conversion to ammonia through the successive hydrodeoxygenation pathway.
基金supported by the National Key Research and Development Program of China(2021YFA1501500 and 2018YFA0704502)the National Natural Science Foundation of China(22171265,22201286,22033008 and 22220102005)+2 种基金Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ103)the Open Research Fund of CNMGE Platform&NSCC-TJthe Open Science Promotion Plan 2023 of CSTCloud。
文摘The special electronic characteristics and high atom usage efficiency of metal-nitrogen-carbon(M-N-C)materials have made them extremely attractive for oxygen reduction reactions(ORRs).However,it is inevitable that hydrogen peroxide(H_(2)O_(2))will be formed via the two-electron pathway in ORRs.Herein,the Cu nanoparticles(NPs)have been encapsulated into Ni doped hollow mesoporous carbon spheres(Ni-HMCS)to reduce the generation of H_(2)O_(2)in ORR.Electrochemical tests confirm that the introduction of Cu NPs improves the ORR performance greatly.The obtained Cu/Ni-HMCS exhibits a half-wave potential of 0.82 V vs.reversible hydrogen electrode and a limited current density of 5.5 mA cm^(-2),which is comparable with the commercial Pt/C.Moreover,Cu/Ni-HMCS has been used in Zn-air battery,demonstrating a high power density of 161 mW cm^(-2)and a long-term recharge capability(50 h at 5 mA cm^(-2)).The theoretical calculation proposes a tandem catalysis pathway for Cu/Ni multi-sites catalysis,that is,H_(2)O_(2)released from the Ni-N_(4)and Cu-N_(4)sites migrates to the Cu(111)face,on which the captive H_(2)O_(2)is further reduced to H_(2)O.This work demonstrates an interesting tandem catalytic pathway of dual-metal multi-sites for ORR,which provides an insight into the development of effective fuel cell electrocatalysts.
基金the National Natural Science Foundation of China(No.22078328)the Key Research Program of Nanjing IPE Institute of Green Manufacturing Industry。
文摘In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction method.The size of Pt nanoparticles(NPs)is effectively controlled by doping with Mn and N.With the smallest average particle size of 1.7 nm,Mn-Pt/NKB demonstrates half-wave potentials of 0.890 and 0.688 V in the alkaline and neutral electrolytes,respectively,which are superior to those of commercial platinum on activated carbon(Pt/C).When applied as an air cathode in aluminum-air battery,it exhibits ultra-high power densities of 190(alkaline)and 26.2 mW·cm^(−2)(neutral).Moreover,the voltage remains stable after 5 h of discharge.The practical application performance of the Mn-Pt/NKB catalyst in an aluminum-air battery is better than that of commercial Pt/C.Furthermore,the oxygen reduction reaction(ORR)mechanism on surfaces with different particle sizes is analyzed using density functional theory.Oxygen cracking is the major pathway on the surface of the small particles with lower energy consumption of 0.5 eV,while water molecule cleavage is the major pathway on the surface of the large particles with higher energy consumption of 0.97 eV.The lower energy consumption of the oxygen cracking pathway further confirms the ORR mechanism for higher activity on small-sized surfaces.This study provides a direction for the rational design of Pt-based catalysts for ORR and sheds light on the commercial development of aluminum-air batteries.
基金supported by the National Natural Science Foundation of China(22271213(B.Z.)and 22071173(Y.Y.))the Haihe Laboratory of Sustainable Chemical Transformationsthe National Postdoctoral Science Foundation of China(2022M722357(Y.W.))。
文摘Hydroxylamine(NH_(2)OH),a vital but unstable industrial feedstock,is presently prepared under harsh conditions that cause environmental and energy concerns.Here,we report an electrochemical method to prepare oximes,which serve as precursors for NH_(2)OH after facile hydrolysis.The carbon-supported amorphous Mn electrocatalyst delivers a current density of~100 mA cm^(-2) with a Faradaic efficiency of 40.92%and a yield rate of 0.251 mmol cm^(-2)h^(-1) for formaldoxime(CH_(2)NOH)generation by using nitrate and formaldehyde as reactants.Formaldoxime can be easily released to produce NH_(2)OH via hydrolysis.Impressively,this method exhibits an economic advantage over conventional manufacturing based on techno-economic analysis.A series of control experiments,in situ characterizations,and theoretical simulations unveil the reaction mechanism via the spontaneous reaction between an aldehyde and*NH_(2)OH intermediate derived from nitrate electroreduction.The high activity of Mn originates from its inhibitory effects on the further reduction of key*NH_(2)OH intermediate.This strategy opens a sustainable and green way for NH_(2)OH synthesis under mild conditions using renewable energy.
基金National Natural Science Foundation of China(Grant number 31572428).
文摘Methane(CH4)production from ruminants accounts for 16%of the global greenhouse gas emissions and represents 2%to 12%of feed energy.Mitigating CH_(4) production from ruminants is of great importance for sustainable development of the ruminant industry.H_(2) is the primary substrate for CH_(4) production in the processes of ruminal methanogenesis.Sulfate reducing bacteria are able to compete with methanogens for H_(2) in the rumen,and consequently inhibit the methanogenesis.Enhancing the ruminal sulfate reducing pathway is an important approach to mitigate CH_(4) emissions in ruminants.The review summarized the effects of sulfate and elemental S on ruminal methanogenesis,and clarified the related mechanisms through the impacts of sulfate and elemental S on major ruminal sulfate reducing bacteria.Enhancing the activities of the major ruminal sulfate reducing bacteria including Desulfovibrio,Desulfohalobium and Sulfolobus through dietary sulfate addition,elemental S and dried distillers grains with solubles can effectively decrease the ruminal CH_(4) emissions.Suitable levels of dietary addition with different S sources for reducing the ruminal CH_(4) production,as well as maintaining the performance and health of ruminants,need to be investigated in the future.
文摘Statins,which are competitive inhibitors of 3-hydroxy-3-methyl-glutarylcoenzyme A reductase,reduce cholesterol blood levels and the risk of developing cardiovascular diseases and their related complications.In addition to this main activity,statins show pleiotropic effects such as antioxidant,anti-inflammatory and antiproliferative properties,with applications in many pathologies.Based on their antiproliferative properties,in vitro and in vivo studies have investigated their effects on various types of cancer(i.e.,breast cancer,prostate cancer,colorectal cancer,ovarian cancer,lung cancer)with different genetic and molecular characteristics.Many positive results were obtained,but they were highly dependent on the physiochemical properties of the statins,their dose and treatment period.Combined therapies of statins and cytotoxic drugs have also been tested,and synergistic or additive effects were observed.Moreover,observational studies performed on patients who used statins for different pathologies,revealed that statins reduced the risk of developing various cancers,and improved the outcomes for cancer patients.Currently,there are many ongoing clinical trials aimed at exploring the potential of statins to lower the mortality and the disease-recurrence risk.All these results are the foundation of new treatment directions in cancer therapy.
