Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure a...Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.展开更多
Rational design of electrocatalysts is important for a sustainable oxygen evolution reaction(OER).It is still a huge challenge to engineer active sites in multi-sizes and multi-components simultaneously.Here,a series ...Rational design of electrocatalysts is important for a sustainable oxygen evolution reaction(OER).It is still a huge challenge to engineer active sites in multi-sizes and multi-components simultaneously.Here,a series of CoxP nanoparticles(NPs)confined in an SiO2matrix(SiO2/CoxP)is designed and synthesized as OER electrocatalysts.The phosphorization of the hydrolyzed Co-phyllosilicate promotes the formation of ultrasmall and small Co2P and CoP.These are firmly confined in the SiO2matrix.The coupling of multi-size and multi-component CoxP catalysts can regulate reaction kinetics and electron transfer ability,enrich the active sites,and eventually promote the intrinsic OER activity.The SiO2matrix provides abundant porous structure and oxygen vacancies,and these facilitate the exposure of active sites and improve conductivity.Because of the synergy and interplay of multisized/component CoxP NPs and the porous SiO2matrix,the unique SiO2/CoxP heterostructure exhibits low overpotential(293 m V@10 mA cm-2),and robust stability(decay 12 mV after 5000 CV cycles,97.4%of initial current after 100 h chronoamperometric)for the OER process,exceeding many advanced metal phosphide electrocatalysts.This work provides a novel tactic to design low-cost,simple,and highly efficient OER electrocatalysts.展开更多
To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthre...To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthrene as the organic modifier.The impacts of FP-NiPS on the thermal stability,flame retardancy,and mechanical and tribological properties of EP composites were explored.The findings demonstrated that 5 wt%FP-NiPS elevated the limiting oxygen index of the EP composite from 23.8%to 28.4%,achieving a V-0 rating during vertical burning tests.FP-NiPS could enhance the thermal stability of epoxy resin(EP)and facilitate the development of a dense and continuous carbon layer,thereby significantly improving the fire safety of the EP composites.The FP-NiPS led to an 8.2%increase in the tensile strength and a 38.8%increase in the elastic modulus of the EP composite,showing outstanding mechanical properties.Furthermore,FP-NiPS showed remarkable potential in enhancing the wear resistance of EP.The wear rate of 1 wt%FP-NiPS is 2.34×10^(−5) mm^(3)·N^(−1)·m^(−1),a decrease of 66.7%compared to EP.This work provides a novel promising modification method to enhance the fire safety,mechanical and wear resistance properties of EP.展开更多
Selective hydrogenation of hydroxyaldehydes to polyalcohols is challenging due to the competitive hydrogenation of C=O and CAO.This study develops heterogeneous Cu catalysts for the selective synthesis of ethylene gly...Selective hydrogenation of hydroxyaldehydes to polyalcohols is challenging due to the competitive hydrogenation of C=O and CAO.This study develops heterogeneous Cu catalysts for the selective synthesis of ethylene glycol via batch liquid-phase hydrogenation of glycolaldehyde.SiO_(2)supported Cu,fabricated by ammonia evaporation,enables to catalyze the C=O bond hydrogenation with retaining the CAO bond intact,yielding higher selective hydrogenation activity with ethylene glycol selectivity up to 99.8%relative to MgO,Al_(2)O_(3),CeO_(2),and TiO_(2)supports and Cu/SiO_(2)synthesized by deposition–precipitation and impregnation.Characterizations confirm that highly efficient 20Cu/SiO_(2)-AE-623 K catalyst fabricated by ammonia evaporation is featured with larger Cu^(0)and Cu^(+)surface areas,of which the Cu^(+)species created from reducing copper phyllosilicate exhibit higher reactivity.A synergistic effect between Cu^(+)and Cu^(0)facilitates the selective adsorption/activation of glycolaldehyde on Cu^(+)sites and the dissociation of H_(2)on Cu^(0)sites,bringing a remarkable improvement in the selective hydrogenation performance.展开更多
The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process.The flower-like nickel phyllosilicate particles were firstly synthesized us...The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process.The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method,and the morphology and lamellar structure were examined carefully.Several properties of mechanical,thermal and tribological responses of epoxy nanocomposites were performed.It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix,and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected.In addition,friction coefficient and wear rate were increased first and then decreased along with the particle content,and showed the lowest values at a mass fraction of 5%.Nevertheless,the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin(EP)nanocomposites.This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.展开更多
In this study,nickel phyllosilicate was synthesized based on molybdenum disulfide(MoS2@NiPS)by the sol-gel method,and then MoS2@NiPS was used to prepare epoxy composites.The thermal stability,flame retardancy,and fric...In this study,nickel phyllosilicate was synthesized based on molybdenum disulfide(MoS2@NiPS)by the sol-gel method,and then MoS2@NiPS was used to prepare epoxy composites.The thermal stability,flame retardancy,and frictional performances of epoxy composites were studied.With the addition of 3 wt%MoS2@NiPS,the epoxy composite increased the limiting oxygen index from 23.8%to 26.1%and reduced the vertical burning time from 166 s for epoxy resin to 35 s.The residual char of the epoxy composite increased from 11.8 to 20.2 wt%.MoS2@NiPS promoted the graphitization of the residual char,and facilitated the formation of a dense and continuous char layer,thereby improving the fire safety of epoxy resin.The epoxy composite with 3 wt%MoS2@NiPS had excellent wear resistance property with a wear rate of 2.19×10^(‒5) mm^(3)·N^(-1)·m^(-1),which was 68.8%lower than that of epoxy resin.This study presented a practical approach to improve the frictional and fire resistance of epoxy composites.展开更多
Poor interfacial adhesion and dispersity severely obstruct the continued development of carbon nanotube(CNT)-reinforced epoxy(EP)for potential applications.Herein,hierarchical CNT nanohybrids using nickel phyllosilica...Poor interfacial adhesion and dispersity severely obstruct the continued development of carbon nanotube(CNT)-reinforced epoxy(EP)for potential applications.Herein,hierarchical CNT nanohybrids using nickel phyllosilicate(Ni-PS)as surface decorations(CNT@Ni-PS)were synthesized,and the nanocomposites derived from varied mass fractions of EP and CNT@Ni-PS were prepared.The morphological structures,tribological performances,curing behaviors and thermal properties of EP/CNT@Ni-PS nanocomposites were carefully investigated.Results show that hierarchical CNT nanohybrids with homogeneous dispersion and well-bonded interfacial adhesion in the matrix are successfully obtained,presenting significantly improved thermal and tribological properties.Moreover,analysis on cure kinetics proves the excellent promotion of CNT@Ni-PS on the non-isothermal curing process,lowering the curing energy barrier steadily.展开更多
Metal−organic framework-derived materials have attracted significant attention in the applications of functional materials.In this work,the rod-like nickel-based metal−organic frameworks were first synthesized and sub...Metal−organic framework-derived materials have attracted significant attention in the applications of functional materials.In this work,the rod-like nickel-based metal−organic frameworks were first synthesized and subsequently employed as the hard templates and nickel sources to prepare the whisker-shaped nickel phyllosilicate using a facile hydrothermal technology.Then,the nickel phyllosilicate whiskers were evaluated to enhance the mechanical,thermal,flammable,and tribological properties of epoxy resin.The results show that adequate nickel phyllosilicate whiskers can disperse well in the matrix,improving the tensile strength and elastic modulus by 13.6%and 56.4%,respectively.Although the addition of nickel phyllosilicate whiskers could not obtain any UL-94 ratings,it enhanced the difficulty in burning the resulted epoxy resin nanocomposites and considerably enhanced thermal stabilities.Additionally,it was demonstrated that such nickel phyllosilicate whiskers preferred to improve the wear resistance instead of the antifriction feature.Moreover,the wear rate of epoxy resin nanocomposites was reduced significantly by 80%for pure epoxy resin by adding 1 phr whiskers.The as-prepared nickel phyllosilicate whiskers proved to be promising reinforcements in preparing of high-performance epoxy resin nanocomposites.展开更多
文摘Cu/SiO2 catalysts prepared by a convenient and efficient method using the urea hydrolysis deposition-precipitation （UHDP） technique have been proposed focusing on the effect of copper loading.The texture,structure and composition are systematically characterized by ICP,FTIR,N 2-physisorption,N2O chemisorption,TPR,XRD and XPS.The formation of copper phyllosilicate is observed in Cu/SiO2 catalyst by adopting UHDP method,and the amount of copper phyllosilicate is related to copper loading.It is found the structure properties and catalytic performance is profoundly affected by the amount of copper phyllosilicate.The excellent catalytic activity is attributed to the synergetic effect between Cu0 and Cu ＋.DMO conversion and EG selectivity are determined by the amount of Cu0 and Cu＋,respectively.The proper copper loading （30 wt%） provides with the highest ratio of Cu ＋ /Cu0,giving rise to the highest EG yield of 95% under the reaction conditions of p=2.0 MPa,T=473 K,H2/DMO=80 and LHSV=1.0h-1.
基金supported by the Training Program for Academic and Technical Leaders of Major Disciplines in Jiangxi Province(No.20212BCJ23020)the Science and Technology Project of Jiangxi Provincial Department of Education(No.GJJ211305)+1 种基金the National Natural Science Foundation of China(No.51671010)the National University Students Innovation and Entrepreneurship Training Program(No.202110408005)。
文摘Rational design of electrocatalysts is important for a sustainable oxygen evolution reaction(OER).It is still a huge challenge to engineer active sites in multi-sizes and multi-components simultaneously.Here,a series of CoxP nanoparticles(NPs)confined in an SiO2matrix(SiO2/CoxP)is designed and synthesized as OER electrocatalysts.The phosphorization of the hydrolyzed Co-phyllosilicate promotes the formation of ultrasmall and small Co2P and CoP.These are firmly confined in the SiO2matrix.The coupling of multi-size and multi-component CoxP catalysts can regulate reaction kinetics and electron transfer ability,enrich the active sites,and eventually promote the intrinsic OER activity.The SiO2matrix provides abundant porous structure and oxygen vacancies,and these facilitate the exposure of active sites and improve conductivity.Because of the synergy and interplay of multisized/component CoxP NPs and the porous SiO2matrix,the unique SiO2/CoxP heterostructure exhibits low overpotential(293 m V@10 mA cm-2),and robust stability(decay 12 mV after 5000 CV cycles,97.4%of initial current after 100 h chronoamperometric)for the OER process,exceeding many advanced metal phosphide electrocatalysts.This work provides a novel tactic to design low-cost,simple,and highly efficient OER electrocatalysts.
基金Youth Scientific Research Project in Anhui Province(Grant No.2022AH020055)the Key Research and Development Projects in Anhui Province(Grant Nos.2022i01020016,2023g07020001)+1 种基金the National Natural Science Foundation of China(Grant No.52074011)the University Synergy innovation Program of Anhui Province(Grant No.GXXT-2022-018).
文摘To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthrene as the organic modifier.The impacts of FP-NiPS on the thermal stability,flame retardancy,and mechanical and tribological properties of EP composites were explored.The findings demonstrated that 5 wt%FP-NiPS elevated the limiting oxygen index of the EP composite from 23.8%to 28.4%,achieving a V-0 rating during vertical burning tests.FP-NiPS could enhance the thermal stability of epoxy resin(EP)and facilitate the development of a dense and continuous carbon layer,thereby significantly improving the fire safety of the EP composites.The FP-NiPS led to an 8.2%increase in the tensile strength and a 38.8%increase in the elastic modulus of the EP composite,showing outstanding mechanical properties.Furthermore,FP-NiPS showed remarkable potential in enhancing the wear resistance of EP.The wear rate of 1 wt%FP-NiPS is 2.34×10^(−5) mm^(3)·N^(−1)·m^(−1),a decrease of 66.7%compared to EP.This work provides a novel promising modification method to enhance the fire safety,mechanical and wear resistance properties of EP.
基金supported by the National Key Research and Development Program of China (2018YFA0704502)Haihe Laboratory of Sustainable Chemical Transformations (CYZC202101)。
文摘Selective hydrogenation of hydroxyaldehydes to polyalcohols is challenging due to the competitive hydrogenation of C=O and CAO.This study develops heterogeneous Cu catalysts for the selective synthesis of ethylene glycol via batch liquid-phase hydrogenation of glycolaldehyde.SiO_(2)supported Cu,fabricated by ammonia evaporation,enables to catalyze the C=O bond hydrogenation with retaining the CAO bond intact,yielding higher selective hydrogenation activity with ethylene glycol selectivity up to 99.8%relative to MgO,Al_(2)O_(3),CeO_(2),and TiO_(2)supports and Cu/SiO_(2)synthesized by deposition–precipitation and impregnation.Characterizations confirm that highly efficient 20Cu/SiO_(2)-AE-623 K catalyst fabricated by ammonia evaporation is featured with larger Cu^(0)and Cu^(+)surface areas,of which the Cu^(+)species created from reducing copper phyllosilicate exhibit higher reactivity.A synergistic effect between Cu^(+)and Cu^(0)facilitates the selective adsorption/activation of glycolaldehyde on Cu^(+)sites and the dissociation of H_(2)on Cu^(0)sites,bringing a remarkable improvement in the selective hydrogenation performance.
基金the National Natural Science Foundation of China(Grant No.51775001)Anhui Province Natural Science Foundation(Grant No.1908085J20)University Synergy Innovation Program of Anhui Province(Grant No.GXXT-2019-027)and the Leading Talents Project in Colleges and Universities of Anhui Province.
文摘The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process.The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method,and the morphology and lamellar structure were examined carefully.Several properties of mechanical,thermal and tribological responses of epoxy nanocomposites were performed.It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix,and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected.In addition,friction coefficient and wear rate were increased first and then decreased along with the particle content,and showed the lowest values at a mass fraction of 5%.Nevertheless,the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin(EP)nanocomposites.This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.
基金gratefully acknowledge Outstanding Youth Scientific Research Project in Anhui Province(Grant No.2022AH020055)Key Research and Development Projects in Anhui Province(Grant No.2022i01020016)+1 种基金the National Natural Science Foundation of China(Grant No.52074011)the University Synergy innovation Program of Anhui Province(Grant No.GXXT-2022-018).
文摘In this study,nickel phyllosilicate was synthesized based on molybdenum disulfide(MoS2@NiPS)by the sol-gel method,and then MoS2@NiPS was used to prepare epoxy composites.The thermal stability,flame retardancy,and frictional performances of epoxy composites were studied.With the addition of 3 wt%MoS2@NiPS,the epoxy composite increased the limiting oxygen index from 23.8%to 26.1%and reduced the vertical burning time from 166 s for epoxy resin to 35 s.The residual char of the epoxy composite increased from 11.8 to 20.2 wt%.MoS2@NiPS promoted the graphitization of the residual char,and facilitated the formation of a dense and continuous char layer,thereby improving the fire safety of epoxy resin.The epoxy composite with 3 wt%MoS2@NiPS had excellent wear resistance property with a wear rate of 2.19×10^(‒5) mm^(3)·N^(-1)·m^(-1),which was 68.8%lower than that of epoxy resin.This study presented a practical approach to improve the frictional and fire resistance of epoxy composites.
基金the National Natural Science Foundation of China(Grant No.51775001)Natural Science Foundation of Anhui Province(Grant No.1908085J20)+1 种基金University Synergy Innovation Program of Anhui Province(Grant No.GXXT-2019-027)the Leading Talents Project in Colleges and Universities of Anhui Province.
文摘Poor interfacial adhesion and dispersity severely obstruct the continued development of carbon nanotube(CNT)-reinforced epoxy(EP)for potential applications.Herein,hierarchical CNT nanohybrids using nickel phyllosilicate(Ni-PS)as surface decorations(CNT@Ni-PS)were synthesized,and the nanocomposites derived from varied mass fractions of EP and CNT@Ni-PS were prepared.The morphological structures,tribological performances,curing behaviors and thermal properties of EP/CNT@Ni-PS nanocomposites were carefully investigated.Results show that hierarchical CNT nanohybrids with homogeneous dispersion and well-bonded interfacial adhesion in the matrix are successfully obtained,presenting significantly improved thermal and tribological properties.Moreover,analysis on cure kinetics proves the excellent promotion of CNT@Ni-PS on the non-isothermal curing process,lowering the curing energy barrier steadily.
基金the Key research and development project in Anhui Province(Grant No.2022i01020016)the National Natural Science Foundation of China(Grant No.51775001)+3 种基金the Anhui Province Natural Science Foundation(Grant Nos.1908085J20,2008085QE269)the University Synergy Innovation Program of Anhui Province(Grant Nos.GXXT-2019-027,GXXT-2020-057)the Natural Science Research Project of Universities in Anhui Province(Grant No.KJ2020A0326)the Leading Talents Project in Colleges and Universities of Anhui Province.
文摘Metal−organic framework-derived materials have attracted significant attention in the applications of functional materials.In this work,the rod-like nickel-based metal−organic frameworks were first synthesized and subsequently employed as the hard templates and nickel sources to prepare the whisker-shaped nickel phyllosilicate using a facile hydrothermal technology.Then,the nickel phyllosilicate whiskers were evaluated to enhance the mechanical,thermal,flammable,and tribological properties of epoxy resin.The results show that adequate nickel phyllosilicate whiskers can disperse well in the matrix,improving the tensile strength and elastic modulus by 13.6%and 56.4%,respectively.Although the addition of nickel phyllosilicate whiskers could not obtain any UL-94 ratings,it enhanced the difficulty in burning the resulted epoxy resin nanocomposites and considerably enhanced thermal stabilities.Additionally,it was demonstrated that such nickel phyllosilicate whiskers preferred to improve the wear resistance instead of the antifriction feature.Moreover,the wear rate of epoxy resin nanocomposites was reduced significantly by 80%for pure epoxy resin by adding 1 phr whiskers.The as-prepared nickel phyllosilicate whiskers proved to be promising reinforcements in preparing of high-performance epoxy resin nanocomposites.
