The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide an...The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide anions have been explored and exhibit excellent catalytic activity.However,halogen salt is generally toxic and corrosive to reactors.From a green chemistry perspective,it is more attractive to develop a halogen-free catalyst with excellent performance.Herein,a review of recent research progress of halogen-free catalysts in the cycloaddition of CO2 and epoxide is presented.According to previous experimental and theoretical works,two possible strategies for achieving the halogen-free process were summarized.The relationship between catalytic activity and catalyst structure,the mechanism of CO2 activation should be both studied deeply combined with experimental results and DFT calculation,which can guide the design of new catalysts and realize halogen-free process under mild reaction conditions.展开更多
The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there a...The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there are difficulties in separation and recovery of traditional homogeneous catalysts,harsh reaction conditions of traditional heterogeneous catalysts,and activation of CO_(2)molecules.In this paper,an easily synthesized heterogeneous catalyst CeNCl/C was used to catalyze the cycloaddition reaction of CO_(2)with styrene oxide,with a high yield of 92.7%,a high selectivity of 96.7%,a turnover numbers(TON)value of 349,and a good stability demonstrated in six cycle tests(equivalent to 216 h of testing).Through comprehensive studies,it was shown that CeNCl/C contains Lewis acid-base centers as active centers,which can effectively reduce the energy barrier required for ring opening of the reaction substrate,enhance the adsorption and activation of CO_(2),and promote the formation of intermediates,which led to the acquisition of excellent catalytic activity.展开更多
Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readi...Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.As the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.展开更多
Researchers working in the field of photovoltaic are exploring novel materials for the efficient solar energy conversion.The prime objective of the discovery of every novel photovoltaic material is to achieve more ene...Researchers working in the field of photovoltaic are exploring novel materials for the efficient solar energy conversion.The prime objective of the discovery of every novel photovoltaic material is to achieve more energy yield with easy fabrication process and less production cost features.Perovskite solar cells (PSCs)delivering the highest efficiency in the passing years with different stoichiometry and fabrication modification have made this technology a potent candidate for future energy conversion materials.Till now,many studies have shown that the quality of active layer morphology,to a great extent,determines the performance of PSCs.The current and potential techniques of solvent engineering for good active layer morphology are mainly debated using primary solvent,co-solvent (Lewis acid-base adduct approach)and solvent additives.In this review,the dynamics of numerously reported solvents on the morphological characteristics of PSCs active layer are discussed in detail.The intention is to get a clear understanding of solvent engineering induced modifications on active layer morphology in PSC devices via different crystallization routes.At last,an attempt is made to draw a framework based on different solvent coordination properties to make it easy for screening the potent solvent contender for desired PSCs precursor for a better and feasible device.展开更多
Cycloaddition of carbon dioxide to epoxides was catalyzed by the binary catalyst systems of phthalocyaninatoaluminium chloride (PcAlCl) and Lewis bases (such as tributylamine, 1 methylimidazole, triphenylphosphine, tr...Cycloaddition of carbon dioxide to epoxides was catalyzed by the binary catalyst systems of phthalocyaninatoaluminium chloride (PcAlCl) and Lewis bases (such as tributylamine, 1 methylimidazole, triphenylphosphine, triethylamine, pyridine and quinoline). The Lewis bases were the excellent promoters, but either component of the binary catalyst systems had low catalytic activity individually. For example, when 0 18 mol of propylene oxide was reacted with 0 36 mol of CO 2 at 140 ℃ for 1 7 h in the presence of 0 18 mmol of PcAlCl and 0 81 mmol of tributylamine, the yield of propylene carbonate was 99 7%; while the yield was 17 4% when used PcAlCl only. Promoting effects of Lewis bases were in the order: 1 methylimidazole>triphenylphosphine>tributylamine>triethylaminepyridinequinoline. Reactivity of the epoxides used was in the order: CH 2Cl>H, CH 3.展开更多
In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selec...In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.展开更多
It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) na...It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) nanocluster with distorted octahedral Cu_(6) core and NH_(2)-functionalized ligands has been developed as the first homo/heterogeneous catalyst to catalyze the cyclization reaction of propargylic amines with carbon dioxide(CO_(2))under mild conditions.As a homogeneous catalyst,Cu_(6)-NH_(2) shows excellent catalytic activity with high turnover frequency due to highly accessible active sites.The definite coordination geometry and homogeneity nature of active centers make it convenient to investigate the structure–activity relationship at the atomic level through experiments and theory calculations.In addition,the nanocluster exhibits excellent stability,great recrystallizability,and reusability in five catalytic cycles,in which its catalytic performance has no obvious decrease.Moreover,Cu_(6)-NH_(2) incorporates Lewis acid and base sites in metal and ligand,respectively,which can promote catalytic efficiency in a synergistic effect in the absence of any cocatalysts.Importantly,Cu_(6)-NH_(2) can realize direct conversion of CO_(2) in simulated flue gas into oxazolidinones with high efficiency.The metal-ligand cooperative effect and integrated advantages of homogeneous and heterogeneous catalysis would provide new perspectives to achieve advanced metal nanocluster catalysts for CO_(2) conversion.展开更多
Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herei...Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.展开更多
The saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton-like catalytic systems.This study developed a MoS_(2)co-catalytic Fe_(2)O_(3)Fenton-like system with controllable Le...The saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton-like catalytic systems.This study developed a MoS_(2)co-catalytic Fe_(2)O_(3)Fenton-like system with controllable Lewis acid-base sites,achieving efficient treatment of various model pollutants and actual industrial wastewater under neutral buffered environment.The acidic microenvironment structured by the edge S sites(Lewis basic sites)in the MoS_(2)/Fe_(2)O_(3)catalyst is susceptible to the influence of Lewis acidic sites constructed by Mo and Fe element,affecting catalytic performance.Optimizing the ratio of precursor amounts ensures the stable presence of the acidic microenvironment on the surface of catalyst,enabling the beneficial co-catalytic effect of Mo sites to be realized.Furthermore,it transcends the rigid constraints imposed by the Fenton reaction on reaction environments,thereby expanding the applicability of commonplace oxides such as Fe_(2)O_(3)in actual industrial water remediation.展开更多
Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes toward...Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes towards substances(3,3’,5,5’-tetramethylbenzidine(TMB)and hydrogen peroxide(H2O2))induced by surface Lewis acid-base sites is important to enhance the efficiency for peroxidase-like reaction.Herein,ultrathin porous Co_(3)O_(4)nanosheets with abundant Lewis acid-base sites were prepared by sodium borohydride(NaBH4)reduction treatment,which exhibited high-efficiency peroxidase-like activity compared with original Co_(3)O_(4)nanosheets.The Lewis acid-base sites for ultrathin porous Co_(3)O_(4)nanosheets nanozyme were owing to the coordination unsaturation of Co ions and the formation of defect structure.Ultrathin porous Co_(3)O_(4)nanosheets had 18.26-fold higher catalytic efficiency(1.27×10^(-2)s^(-1)·mM^(-1))than that of original Co_(3)O_(4)(6.95×10^(-4)s^(-1)·mM^(-1))in oxidizing TMB substrate.The synergistic effect of surface acid and base sites can enhance the interfacial electron transfer process of Co_(3)O_(4)nanosheets,which can be a favor of absorption substrates and the generation of reactive intermediates such as radicals.Furthermore,the limit of detection of hydroquinol was 0.58μM for ultrathin porous Co_(3)O_(4)nanosheets,965-fold lower than original Co_(3)O_(4)(560μM).Besides,the linear range of ultrathin porous Co_(3)O_(4)nanosheets was widely with the concentration of 5.0-1,000μM.Colorimetric detection of hydroquinol by agarose-based hydrogel membrane was provided based on excellent peroxidase-like properties.This study provided insights into designing high-performance nanozymes for peroxidase-like catalysis via a strategy of solid surface acid-base sites engineering.展开更多
The scope of stereochemistry recognition usually occurs near the chiral scaffold of a ligand or catalyst.Remote stereocontrol,which can surpass the limits of stereorecognition of remote prochiral centers,has long been...The scope of stereochemistry recognition usually occurs near the chiral scaffold of a ligand or catalyst.Remote stereocontrol,which can surpass the limits of stereorecognition of remote prochiral centers,has long been a challenging object of great interest in asymmetric catalysis.The current work realized the remote stereocontrol of 1,7-zwitterion intermediates formed from Huang's o-amino aryl MBH carbonates.With simple and easily accessibleβ-ICD as the bifunctional catalyst,multifunctionalized tetrahydroquinoline derivatives could be synthesized via(4+2)cycloadditions with excellent enantioselectivity and diastereoselectivity under mild conditions.The strategy possesses broad substrate scope,and three types of electron-deficient enones are successfully applied.Mechanistic studies disclosed the Lewis base-catalyzed reaction pathway,and H-bonding between the catalyst and enones is crucial for long-range stereocontrol.Scale-up reaction and transformations of the tetrahydroquinoline products demonstrated the potential of this strategy.展开更多
Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphon...Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphonic acid（RNPP） and dodecencylsuccinic acid（RCC）. The color reaction of RNPP-ZrO2 and RNCP-ZrO2 with ammonium molybdate indicate there are free phosphonic groups on the surface of the stationary phases, and the FTIR spectra of RNCC-ZrO2 and RNCC-ZrO2 indicate there are free carboxyl groups. The RCC-ZrO2 is far more stable than RNCC-ZrO2 under alkali station. The results of color reaction, FTIR spectra and the stability test of stationary phases suggest that, due to the chelating effect, RNCC, RNCP and RNPP adsorb on zirconia with only one carboxyl or phosphonic group, however, RCC adsorb on zirconia with two carboxyl groups.展开更多
基金supported by the National Key Research and Development Program of China(2018YFB0605801)National Natural Science Foundation of China(21871277)Chinese Academy of Sciences(QYZDYSSW-SLH013).
文摘The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide anions have been explored and exhibit excellent catalytic activity.However,halogen salt is generally toxic and corrosive to reactors.From a green chemistry perspective,it is more attractive to develop a halogen-free catalyst with excellent performance.Herein,a review of recent research progress of halogen-free catalysts in the cycloaddition of CO2 and epoxide is presented.According to previous experimental and theoretical works,two possible strategies for achieving the halogen-free process were summarized.The relationship between catalytic activity and catalyst structure,the mechanism of CO2 activation should be both studied deeply combined with experimental results and DFT calculation,which can guide the design of new catalysts and realize halogen-free process under mild reaction conditions.
基金supported by the financial aid from the National Key Research and Development Program of China(No.2021YFB3500700)the National Natural Science Foundation of China(Nos.22020102003,22025506,22271274 and U23A20140)+2 种基金Jilin Province Science and Technology Development Plan Project(No.20230101022JC)Hunan Province High-tech Industry Science and Technology Innovation Leading Plan(No.2022GK4021)funding from National Natural Science Foundation of China Outstanding Youth Science Foundation of China(Overseas).
文摘The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there are difficulties in separation and recovery of traditional homogeneous catalysts,harsh reaction conditions of traditional heterogeneous catalysts,and activation of CO_(2)molecules.In this paper,an easily synthesized heterogeneous catalyst CeNCl/C was used to catalyze the cycloaddition reaction of CO_(2)with styrene oxide,with a high yield of 92.7%,a high selectivity of 96.7%,a turnover numbers(TON)value of 349,and a good stability demonstrated in six cycle tests(equivalent to 216 h of testing).Through comprehensive studies,it was shown that CeNCl/C contains Lewis acid-base centers as active centers,which can effectively reduce the energy barrier required for ring opening of the reaction substrate,enhance the adsorption and activation of CO_(2),and promote the formation of intermediates,which led to the acquisition of excellent catalytic activity.
基金the National Natural Science Foundation of China(Nos.22071149,21871178)the Natural Science Foundation of Shanghai(23ZR1428200)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning for financial support.
文摘Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time.Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.As the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.
基金supported by the National Key Research and Development Program of China (2016YFA0202400)the 111 project (B16016)the National Natural Science Foundation of China (51572080, 51702096, and U1705256)
文摘Researchers working in the field of photovoltaic are exploring novel materials for the efficient solar energy conversion.The prime objective of the discovery of every novel photovoltaic material is to achieve more energy yield with easy fabrication process and less production cost features.Perovskite solar cells (PSCs)delivering the highest efficiency in the passing years with different stoichiometry and fabrication modification have made this technology a potent candidate for future energy conversion materials.Till now,many studies have shown that the quality of active layer morphology,to a great extent,determines the performance of PSCs.The current and potential techniques of solvent engineering for good active layer morphology are mainly debated using primary solvent,co-solvent (Lewis acid-base adduct approach)and solvent additives.In this review,the dynamics of numerously reported solvents on the morphological characteristics of PSCs active layer are discussed in detail.The intention is to get a clear understanding of solvent engineering induced modifications on active layer morphology in PSC devices via different crystallization routes.At last,an attempt is made to draw a framework based on different solvent coordination properties to make it easy for screening the potent solvent contender for desired PSCs precursor for a better and feasible device.
文摘Cycloaddition of carbon dioxide to epoxides was catalyzed by the binary catalyst systems of phthalocyaninatoaluminium chloride (PcAlCl) and Lewis bases (such as tributylamine, 1 methylimidazole, triphenylphosphine, triethylamine, pyridine and quinoline). The Lewis bases were the excellent promoters, but either component of the binary catalyst systems had low catalytic activity individually. For example, when 0 18 mol of propylene oxide was reacted with 0 36 mol of CO 2 at 140 ℃ for 1 7 h in the presence of 0 18 mmol of PcAlCl and 0 81 mmol of tributylamine, the yield of propylene carbonate was 99 7%; while the yield was 17 4% when used PcAlCl only. Promoting effects of Lewis bases were in the order: 1 methylimidazole>triphenylphosphine>tributylamine>triethylaminepyridinequinoline. Reactivity of the epoxides used was in the order: CH 2Cl>H, CH 3.
基金the funding support from the National Natural Science Foundation of China(Nos.22202036 and 22302001)the Jilin Province Scientific,the Technological Planning Project of China(No.20230101292JC).
文摘In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.
基金financially supported by the National Natural Science Foundation of China(grant nos.92061201,21825106,21771163,and 22371263)the National Key R&D Program of China(grant no.2021YFA1200301)+1 种基金the Natural Science Foundation of Henan Province(grant no.232300421144)the Zhongyuan Thousand Talents(Zhongyuan Scholars)Program of Henan Province(grant no.234000510007).
文摘It remains a significant challenge to develop a catalyst that merges the advantages of homogeneous and heterogeneous catalysis with high reactivity and great recyclability.Herein,an atomically precise Cu_(6)-NH_(2) nanocluster with distorted octahedral Cu_(6) core and NH_(2)-functionalized ligands has been developed as the first homo/heterogeneous catalyst to catalyze the cyclization reaction of propargylic amines with carbon dioxide(CO_(2))under mild conditions.As a homogeneous catalyst,Cu_(6)-NH_(2) shows excellent catalytic activity with high turnover frequency due to highly accessible active sites.The definite coordination geometry and homogeneity nature of active centers make it convenient to investigate the structure–activity relationship at the atomic level through experiments and theory calculations.In addition,the nanocluster exhibits excellent stability,great recrystallizability,and reusability in five catalytic cycles,in which its catalytic performance has no obvious decrease.Moreover,Cu_(6)-NH_(2) incorporates Lewis acid and base sites in metal and ligand,respectively,which can promote catalytic efficiency in a synergistic effect in the absence of any cocatalysts.Importantly,Cu_(6)-NH_(2) can realize direct conversion of CO_(2) in simulated flue gas into oxazolidinones with high efficiency.The metal-ligand cooperative effect and integrated advantages of homogeneous and heterogeneous catalysis would provide new perspectives to achieve advanced metal nanocluster catalysts for CO_(2) conversion.
基金supported by the National Natural Science Foundation of China (52161025)the Natural Science Foundation of Gansu Province (20JR10RA241)。
文摘Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.
基金supported by the National Natural Science Foundation of China(Nos.22176060 and 41876189)the Program of Shanghai Academic/Technology Research Leader(23XD1421000)+3 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2018SHZDZX03)the Program of Introducing Talents of Discipline to Universities(B16017)Science and Technology Commission of Shanghai Municipality(20DZ2250400)the Fundamental Research Funds for the Central Universities(222201717003)。
文摘The saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton-like catalytic systems.This study developed a MoS_(2)co-catalytic Fe_(2)O_(3)Fenton-like system with controllable Lewis acid-base sites,achieving efficient treatment of various model pollutants and actual industrial wastewater under neutral buffered environment.The acidic microenvironment structured by the edge S sites(Lewis basic sites)in the MoS_(2)/Fe_(2)O_(3)catalyst is susceptible to the influence of Lewis acidic sites constructed by Mo and Fe element,affecting catalytic performance.Optimizing the ratio of precursor amounts ensures the stable presence of the acidic microenvironment on the surface of catalyst,enabling the beneficial co-catalytic effect of Mo sites to be realized.Furthermore,it transcends the rigid constraints imposed by the Fenton reaction on reaction environments,thereby expanding the applicability of commonplace oxides such as Fe_(2)O_(3)in actual industrial water remediation.
基金This work was supported by the National Natural Science Foundation of China(No.21876099)Shandong Provincial Natural Science Foundation(No.ZR2017PB007)Shandong Provincial Key Laboratory Project of Test Technology for Material Chemical Safety(No.2018SDCLHX005).
文摘Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes.Understanding the synergistic effect mechanism of Co_(3)O_(4)nanozymes towards substances(3,3’,5,5’-tetramethylbenzidine(TMB)and hydrogen peroxide(H2O2))induced by surface Lewis acid-base sites is important to enhance the efficiency for peroxidase-like reaction.Herein,ultrathin porous Co_(3)O_(4)nanosheets with abundant Lewis acid-base sites were prepared by sodium borohydride(NaBH4)reduction treatment,which exhibited high-efficiency peroxidase-like activity compared with original Co_(3)O_(4)nanosheets.The Lewis acid-base sites for ultrathin porous Co_(3)O_(4)nanosheets nanozyme were owing to the coordination unsaturation of Co ions and the formation of defect structure.Ultrathin porous Co_(3)O_(4)nanosheets had 18.26-fold higher catalytic efficiency(1.27×10^(-2)s^(-1)·mM^(-1))than that of original Co_(3)O_(4)(6.95×10^(-4)s^(-1)·mM^(-1))in oxidizing TMB substrate.The synergistic effect of surface acid and base sites can enhance the interfacial electron transfer process of Co_(3)O_(4)nanosheets,which can be a favor of absorption substrates and the generation of reactive intermediates such as radicals.Furthermore,the limit of detection of hydroquinol was 0.58μM for ultrathin porous Co_(3)O_(4)nanosheets,965-fold lower than original Co_(3)O_(4)(560μM).Besides,the linear range of ultrathin porous Co_(3)O_(4)nanosheets was widely with the concentration of 5.0-1,000μM.Colorimetric detection of hydroquinol by agarose-based hydrogel membrane was provided based on excellent peroxidase-like properties.This study provided insights into designing high-performance nanozymes for peroxidase-like catalysis via a strategy of solid surface acid-base sites engineering.
基金the National Natural Science Foundation of China(Nos.82073997 and 22001024)the Science&Technology Department of Sichuan Province(Nos.2021YFS0044 and 2021YJ0402)+1 种基金Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(No.ZYYCXTD-D-202209)Xinglin Scholar Research Promotion Project of Chengdu University of TCM.
文摘The scope of stereochemistry recognition usually occurs near the chiral scaffold of a ligand or catalyst.Remote stereocontrol,which can surpass the limits of stereorecognition of remote prochiral centers,has long been a challenging object of great interest in asymmetric catalysis.The current work realized the remote stereocontrol of 1,7-zwitterion intermediates formed from Huang's o-amino aryl MBH carbonates.With simple and easily accessibleβ-ICD as the bifunctional catalyst,multifunctionalized tetrahydroquinoline derivatives could be synthesized via(4+2)cycloadditions with excellent enantioselectivity and diastereoselectivity under mild conditions.The strategy possesses broad substrate scope,and three types of electron-deficient enones are successfully applied.Mechanistic studies disclosed the Lewis base-catalyzed reaction pathway,and H-bonding between the catalyst and enones is crucial for long-range stereocontrol.Scale-up reaction and transformations of the tetrahydroquinoline products demonstrated the potential of this strategy.
文摘Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphonic acid（RNPP） and dodecencylsuccinic acid（RCC）. The color reaction of RNPP-ZrO2 and RNCP-ZrO2 with ammonium molybdate indicate there are free phosphonic groups on the surface of the stationary phases, and the FTIR spectra of RNCC-ZrO2 and RNCC-ZrO2 indicate there are free carboxyl groups. The RCC-ZrO2 is far more stable than RNCC-ZrO2 under alkali station. The results of color reaction, FTIR spectra and the stability test of stationary phases suggest that, due to the chelating effect, RNCC, RNCP and RNPP adsorb on zirconia with only one carboxyl or phosphonic group, however, RCC adsorb on zirconia with two carboxyl groups.
