The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support,...The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.展开更多
Renewable-energy-powered electrochemical CO or CO_(2)reduction reactions(CO_(2)RR)provide one of the most promising strategies to upgrade CO_(2)to valuable products.In the past decade,the existence and the mechanistic...Renewable-energy-powered electrochemical CO or CO_(2)reduction reactions(CO_(2)RR)provide one of the most promising strategies to upgrade CO_(2)to valuable products.In the past decade,the existence and the mechanistic role of oxygen-containing species,such as(sub)surface oxide,hydroxide and oxyhydroxide species,at the electrode–electrolyte interface under reductive conditions have emerged as a topic of acute discussion within the CO_(2)RR field.Oxide-derived Cu attracted the most attention,while other surfaces,including Au,Ag and Sn,were also widely investigated.This review identifies likely causes for contrasting results and views in the literature,summarizes possible oxygen sources for the interfacial oxygen-containing species at the CO_(2)RR conditions,and discusses potential roles these species could play in affecting the rate and product distribution.Finally,perspectives on future efforts to reveal the identity and role of oxygen-containing species in the CO_(2)RR are presented.展开更多
Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability o...Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.展开更多
Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ ...Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.展开更多
A series of copper catalysts with a core-shell or tubular structure containing various contents of Cu, Cu2O, and CuO were prepared via controlled oxidation of Cu nanowires （NWs） and used in the synthesis of dimethyl...A series of copper catalysts with a core-shell or tubular structure containing various contents of Cu, Cu2O, and CuO were prepared via controlled oxidation of Cu nanowires （NWs） and used in the synthesis of dimethyldichlorosilane （M2） via the Rochow reaction. The Cu NWs were prepared from copper （Ⅱ） nitrate using a solution-based reduction method. The samples were characterized by X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy. It was found that the morphology and composition of the catalysts could be tailored by varying the oxidation temperature and time. During the gradual oxidation of Cu NWs, the oxidation reaction inflated on the outer surface and gradually developed into the bulk of the NWs, leading to the formation of catalysts with various structures and layered compositions, e.g., Cu NWs with surface Cu2O, ternary Cu-Cu2O-CuO core-shell NWs, binary Cu2O-CuO nanotubes （NTs）, and single CuO NTs. Among these catalysts, ternary Cu-Cu2O-CuO core-shell NWs exhibited superior M2 selectivity and Si conversion in the Rochow reaction. The enhanced catalytic performance was mainly attributed to improved mass and heat transfer resulting from the peculiar heterostructure and the synergistic effect among layered components. Our work indicated that the catalytic property of Cu-based nanoparticles can be improved by carefully controlling their structures and compositions.展开更多
Electrocatalytic upgrading of biomass-derived platform molecules has emerged as a sustainable and environmentally benign route to produce high-value chemicals.The main challenge lies in developing efficient catalysts ...Electrocatalytic upgrading of biomass-derived platform molecules has emerged as a sustainable and environmentally benign route to produce high-value chemicals.The main challenge lies in developing efficient catalysts for the selective activation of designated chemical bonds in the presence of various reducible groups.This work demonstrated a high-efficiency electrochemical conversion of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF),an important industrial synthetic reagent.A highly porous Cu-based catalyst was developed that achieved nearly 100%BHMF selectivity and long-term stability.Through comprehensive operando and ex-situ structural characterizations,an electrochemically generated catalyst with abundant Cu/Cu2O interfaces was identified as a catalytically active phase for HMF conversion.Deuterated BHMF,with the potential to produce deuterated drugs,was also synthesized using D2O as the deuterium source.Density functional theory calculations show that the Cu/Cu2O interface structure exhibits relatively low energy barriers for the hydrogenation of HMF to BHMF.This work provides insights into the origin of electrocatalytic hydrogenation activity and highlights the promising potential of the electrocatalytic synthesis of high-value chemicals.展开更多
In this work, we report a simple and inexpensive approach to synthesize effective multicomponent Cu-Cu2O-CuO catalysts for the Rochow process from industrial waste contact masses （WCMs）. WCMs from the organosilane i...In this work, we report a simple and inexpensive approach to synthesize effective multicomponent Cu-Cu2O-CuO catalysts for the Rochow process from industrial waste contact masses （WCMs）. WCMs from the organosilane industry were treated with acid followed by reduction with metallic iron powder. The obtained copper powder was then subjected to controlled oxidation in air at different temperatures, followed by ball milling. The orthogonal array approach was applied to optimize this process, and the stirring speed and pH were found to significantly affect the leaching ratio and copper yield, respectively. When used for the Rochow process, the optimized ternary Cu-Cu2O-CuO catalyst greatly enhanced the dimethyldichlorosilane selectivity and Si conversion compared with Cu-Cu2O-CuO catalysts prepared without ball milling, bare Cu catalysts, and Cu-Cu2O-CuO catalysts with different compositions. This could be attributed to their small particle size and the strong synergistic effect among the multiple components in the catalyst with the optimized composition.展开更多
文摘The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.
基金supported by Beijing National Laboratory for Molecular Sciences and the National Natural Science Foundation of China(21872079)。
文摘Renewable-energy-powered electrochemical CO or CO_(2)reduction reactions(CO_(2)RR)provide one of the most promising strategies to upgrade CO_(2)to valuable products.In the past decade,the existence and the mechanistic role of oxygen-containing species,such as(sub)surface oxide,hydroxide and oxyhydroxide species,at the electrode–electrolyte interface under reductive conditions have emerged as a topic of acute discussion within the CO_(2)RR field.Oxide-derived Cu attracted the most attention,while other surfaces,including Au,Ag and Sn,were also widely investigated.This review identifies likely causes for contrasting results and views in the literature,summarizes possible oxygen sources for the interfacial oxygen-containing species at the CO_(2)RR conditions,and discusses potential roles these species could play in affecting the rate and product distribution.Finally,perspectives on future efforts to reveal the identity and role of oxygen-containing species in the CO_(2)RR are presented.
基金support from the National Natural Science Foundation of China(22078130)the Fundamental Research Funds for the Central Universities(1042050205225990/010)Starting Research Fund of Qingyuan Innovation Laboratory(00523001).
文摘Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.
基金the financial support provided by the National Natural Science Foundation of China(Grant No.11872013).
文摘Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.
基金This work was partially funded by the Key R&D Programs of Shandong Province,China(Grant Nos.2018CXGC1411 and 2021CXGC010514).
文摘Cuproptosis shows enormous application prospects in lung metastasis treatment.However,the glycolysis,Cu^(+)efflux mechanisms,and insufficient lung drug accumulation severely restrict cuproptosis efficacy.Herein,an inhalable poly(2-(N-oxide-N,N-diethylamino)ethyl methacrylate)(OPDEA)-coated copper-based metal–organic framework encapsulating pyruvate dehydrogenase kinase 1 siRNA(siPDK)is constructed for mediating cuproptosis and subsequently promoting lung metastasis immunotherapy,namely OMP.After inhalation,OMP shows highly efficient lung accumulation and long-term retention,ascribing to the OPDEA-mediated pulmonary mucosa penetration.Within tumor cells,OMP is degraded to release Cu2+under acidic condition,which will be reduced to toxic Cu^(+)to induce cuproptosis under glutathione(GSH)regulation.Meanwhile,siPDK released from OMP inhibits intracellular glycolysis and adenosine-5ʹ-triphosphate(ATP)production,then blocking the Cu^(+)efflux protein ATP7B,thereby rendering tumor cells more sensitive to OMP-mediated cuproptosis.Moreover,OMP-mediated cuproptosis triggers immunogenic cell death(ICD)to promote dendritic cells(DCs)maturation and CD8^(+)T cells infiltration.Notably,OMP-induced cuproptosis up-regulates membrane-associated programmed cell death-ligand 1(PD-L1)expression and induces soluble PD-L1 secretion,and thus synergizes with anti-PD-L1 antibodies(aPD-L1)to reprogram immunosuppressive tumor microenvironment,finally yielding improved immunotherapy efficacy.Overall,OMP may serve as an efficient inhalable nanoplatform and afford preferable efficacy against lung metastasis through inducing cuproptosis and combining with aPD-L1.
基金Acknowledgements The authors gratefully acknowledge the financial supports from the National Natural Science Foundation of China （Nos. 21506224 and 51272252）. Z. Y. Zhong thanks Institute of Chemical and Engineering Sciences （ICES） for the kind support of the collaboration.
文摘A series of copper catalysts with a core-shell or tubular structure containing various contents of Cu, Cu2O, and CuO were prepared via controlled oxidation of Cu nanowires （NWs） and used in the synthesis of dimethyldichlorosilane （M2） via the Rochow reaction. The Cu NWs were prepared from copper （Ⅱ） nitrate using a solution-based reduction method. The samples were characterized by X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy. It was found that the morphology and composition of the catalysts could be tailored by varying the oxidation temperature and time. During the gradual oxidation of Cu NWs, the oxidation reaction inflated on the outer surface and gradually developed into the bulk of the NWs, leading to the formation of catalysts with various structures and layered compositions, e.g., Cu NWs with surface Cu2O, ternary Cu-Cu2O-CuO core-shell NWs, binary Cu2O-CuO nanotubes （NTs）, and single CuO NTs. Among these catalysts, ternary Cu-Cu2O-CuO core-shell NWs exhibited superior M2 selectivity and Si conversion in the Rochow reaction. The enhanced catalytic performance was mainly attributed to improved mass and heat transfer resulting from the peculiar heterostructure and the synergistic effect among layered components. Our work indicated that the catalytic property of Cu-based nanoparticles can be improved by carefully controlling their structures and compositions.
基金the National Natural Science Foundation of China(21838003,91834301 and 21978278)the Shanghai Scientific and Technological Innovation Project(18JC1410500 and 19JC1410400)the Fundamental Research Funds for the Central Universities(222201718002).
文摘Electrocatalytic upgrading of biomass-derived platform molecules has emerged as a sustainable and environmentally benign route to produce high-value chemicals.The main challenge lies in developing efficient catalysts for the selective activation of designated chemical bonds in the presence of various reducible groups.This work demonstrated a high-efficiency electrochemical conversion of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF),an important industrial synthetic reagent.A highly porous Cu-based catalyst was developed that achieved nearly 100%BHMF selectivity and long-term stability.Through comprehensive operando and ex-situ structural characterizations,an electrochemically generated catalyst with abundant Cu/Cu2O interfaces was identified as a catalytically active phase for HMF conversion.Deuterated BHMF,with the potential to produce deuterated drugs,was also synthesized using D2O as the deuterium source.Density functional theory calculations show that the Cu/Cu2O interface structure exhibits relatively low energy barriers for the hydrogenation of HMF to BHMF.This work provides insights into the origin of electrocatalytic hydrogenation activity and highlights the promising potential of the electrocatalytic synthesis of high-value chemicals.
基金The work was supported by the National Natural Science Foundation of China （grant number 21506224）. Z.Z. is grateful for support from the Institute of Chemical and Engineering Sciences.
文摘In this work, we report a simple and inexpensive approach to synthesize effective multicomponent Cu-Cu2O-CuO catalysts for the Rochow process from industrial waste contact masses （WCMs）. WCMs from the organosilane industry were treated with acid followed by reduction with metallic iron powder. The obtained copper powder was then subjected to controlled oxidation in air at different temperatures, followed by ball milling. The orthogonal array approach was applied to optimize this process, and the stirring speed and pH were found to significantly affect the leaching ratio and copper yield, respectively. When used for the Rochow process, the optimized ternary Cu-Cu2O-CuO catalyst greatly enhanced the dimethyldichlorosilane selectivity and Si conversion compared with Cu-Cu2O-CuO catalysts prepared without ball milling, bare Cu catalysts, and Cu-Cu2O-CuO catalysts with different compositions. This could be attributed to their small particle size and the strong synergistic effect among the multiple components in the catalyst with the optimized composition.
