Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)gene...Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)generate harmful environmental emissions.The desulfurization of BFG is urgent for integrated steel plants due to the stringent ultra-low emission standards.Compared with other desulfurization materials,zeolite-based adsorbents represent a viable option with low costs and long service life.In this study,an ammonia-induced CuO modified 13X adsorbent(NH_(3)–CuO/13X)was prepared for H_(2)S removal from simulated BFG at low temperature.The XRD,H_(2)-TPR and TEM analysis proved that smaller CuO particles were formed and the dispersion of Cu on the surface of 13X zeolite was improved via the induction of ammonia.Evaluation on H_(2)S adsorption performance of the adsorbent was carried out using simulated BFG,and the results showed that NH_(3)–CuO/13X-3 has better breakthrough sulfur capacity,which was more than twice the sulfur capacity of CuO/13X.It is proposed that the enhanced desulfurization performance of NH_(3)–CuO/13X is attributed to an abundant pore of 13X,and combined action of 13X and CuO.This work provided an effective way to improve the sulfur capacity of zeolite-based adsorbents via impregnation method by ammonia induction.展开更多
Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understandi...Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.展开更多
Water pollution caused by organic dyes is a critical environmental issue.Although activated carbon(AC)is commonly used for dye adsorption,its effectiveness is limited by challenges in separation and regeneration.To ad...Water pollution caused by organic dyes is a critical environmental issue.Although activated carbon(AC)is commonly used for dye adsorption,its effectiveness is limited by challenges in separation and regeneration.To address these limitations,a convenient recyclable magnetic activated carbon(MAC)was fabricated via co-precipitation and calcination method,serving as adsorbent and catalyst for methyl orange(MO)removal through a Fenton-like degradation process.Characterization techniques,including XRD,FTIR,SEM and TEM,confirmed that Fe_(3)O_(4) nanoparticles(10–20 nm)were uniformly dispersed on AC surface.The MAC maintaining a high surface area(997 m^(2)/g)and pore volume(0.795 cm^(3)/g)and exhibited superparamagnetic properties with a saturated magnetization of 5.52 emu/g,enabling effective separation from aqueous solutions by magnet.Batch adsorption studies revealed that MO adsorption onto MAC followed pseudo-second-order kinetic and Freundlich isotherm model,with a maximum adsorption capacity of 205 mg/g at 25℃.Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic.Simultaneous degradation of MO and in-situ regeneration of MAC were achieved via Fenton-like reaction using sodium persulfate(PS).Under a PS concentration of 9 mmol/L,the MO removal efficiency near 95%after 60 min,with a total organic carbon(TOC)reduction of 83.1%.The reaction of Fe_(3)O_(4) and oxygen functional groups on AC surface with PS facilitated the generation of SO_(4)^(·-),thereby enhancing catalytic degradation of MO.The degradation efficiency improved as the temperature increased from 25℃ to 45℃.Cycle tests demonstrated that the MO removal efficiency of MAC remained above 90%after 5 cycles of regeneration.Overall,this study highlights the potential of MAC for efficient removal of organic dyes from water through the coupling of adsorption and Fenton-like degradation,providing a promising solution for addressing water pollution challenges.展开更多
Nickel cobalt sulfides (MCo2S4) have attracted considerable attention as electrode materials for supercapacitors. Herein, a sea-urchin-like NiCo2S4 material was synthesized through a one-step solvothermal process. Pol...Nickel cobalt sulfides (MCo2S4) have attracted considerable attention as electrode materials for supercapacitors. Herein, a sea-urchin-like NiCo2S4 material was synthesized through a one-step solvothermal process. Polyethylene glycol (PEG) 200 and thiourea were used as a shape-control age nt and sulfur source for in-s让u sulfuration, respectively. The urchin-like NiC02S4 was characterized by X-ray powder diffraction, scanning electron microscopy, Brunauer-Emmett-Teller surface area, and electrochemical measurements. The resulting NiCo2S4 with ion diffusion-favored structure demonstrated remarkable electrochemical characteristics for supercapacitor with a high specific capacitance (1334F/g at 0.5 A/g) and superior rate capability (78.1% of the original capacity from 0.5 to 20 A/g) in 6M KOH aqueous solution. Furthermore, an asymmetric supercapacitor was assembled using NiCo2S4 as a positive electrode and activated carb on (AC) as a n egative electrode. A NiCo2Sj/AC device exhibited a high energy density of 37.32 Wh/kg at a power density of 317.8 W/kg with capacity retention of 91.9% and up to 2000 charge/discharge cycles at 3 A/g. The results demonstrate that the sea-urchin-like NiCo2S4 has potential applications in supercapacitors.展开更多
A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on ...A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on reaction mechanisms and thermodynamics have revealed that the OCM process is highly exothermic and its C2+selectivity and yield is critical in evaluating its commercial viability.Catalytic strategies have been put to enhance C2+selectivity,improve C2+yield and lower reaction temperature.The catalyst MnNa2WO4/SiO2 enables methane activation at a temperature of 800◦C and simultaneously a high C2+selectivity of 70–80%,while the nanowire and La2O3-based catalysts enable to lower the reaction temperature to 200–300◦C and 500◦C,respectively.Reaction engineering aspects have also been dealt in many investigations in order to make the process technically feasible.Particularly,research works on reaction kinetics,reactor selection and reactor operating mode choice have been addressed.Intermediate cooling and distributed oxygen feed have been integrated into a multi-stage adiabatic fixed-bed reactor system to suppress the side oxidation reactions and improve the performance of the catalysts towards CH4 conversion and C2+yield.This review paper proposes employing a circulating reactor system coupled with catalyst fine particles but having little internal diffusion resistance to maximize one-pass C2+selectivity and yield of the OCM reaction and evaluate its industrial application potential.展开更多
To utilize low rank coal efficiently,a fluidized bed two-stage(FBTS)gasification process,mainly consisting of a FB pyrolyzer and a transport FB(TFB)gasifier,has been proposed for the production of clean fuel gas.To v...To utilize low rank coal efficiently,a fluidized bed two-stage(FBTS)gasification process,mainly consisting of a FB pyrolyzer and a transport FB(TFB)gasifier,has been proposed for the production of clean fuel gas.To verify the feasibility and technical features of this novel gasification technology,a pilot autothermal platform,with a treating capacity of 100 kg/h for coal,was designed and built up.By adopting a kind of lignite from Inner Mongolia,the running state and fuel gas quality were compared systematically under typical operational conditions.The results show that by keeping the reaction temperatures of pyrolyzer and gasifier at around 840C and 1000C,respectively,the corresponding tar content in fuel gas at the outlets of pyrolyzer and gasifier were 1127 mg/Nm3 and 365 mg/Nm3,reaching a high tar removal efficiency.Under the stable operation state,the volume fractions of CO,H2,CH4 and CO2 in fuel gas were 14.4%,8.3%,3.4%and 11.3%,respectively,and the corresponding higher heating value of fuel gas was about 1100 kcal/Nm3.Compared with the tar from pyrolyzer,the heavy oil fraction in tar from gasifier reduced significantly,while the light oil components increased sharply simultaneously,showing significant effect of catalytic reforming by hot char bed on tar removal.展开更多
Owing to high thermal conductivity,carbon nanotube and graphene have been used as nanofillers to improve the thermal conductivity of polymer.However,the agglomeration of nanofillers in polymer inhibits their applicati...Owing to high thermal conductivity,carbon nanotube and graphene have been used as nanofillers to improve the thermal conductivity of polymer.However,the agglomeration of nanofillers in polymer inhibits their applications in improving the thermal conductivity of composite.To overcome this problem,graphene was grown on Ni foam by chemical vapor deposition in this work.And graphene-nickel three-dimensional filler was added into epoxy resin to improve the thermal conductivity of epoxy resin.Ni foam can prevent the agglomeration of graphene in epoxy resin and a thermally conductive network by graphene and Ni foam was formed in epoxy resin.By adding graphene-nickel three-dimensional filler into epoxy resin,the thermal conductivity of graphene-nickel/epoxy composite can reach up to 2.6549 W⋅m^(-1)⋅k^(-1),which was 9 times higher than that of raw epoxy resin.展开更多
In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(N...In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(NPC/rGO-x,x=0.5,1.0,1.5,and 2.0)composites,and thenγ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique.The electrochemical characteristics of porous carbon composites(NPC/rGO-x)andγ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge,cyclic voltammetry,and electrochemical impedance spectroscopy.NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g.Also,theγ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70%capacitance retention after 10,000 cycles at 1 A/g.As a result,this study demonstrates thatγ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.展开更多
A new dual-composition catalyst based on Ni-Mo/MgO with high efficiency of producing carbon nanotubes （CNTs） from methane was reported recently. In the present article, with this type of catalyst, the impact of such...A new dual-composition catalyst based on Ni-Mo/MgO with high efficiency of producing carbon nanotubes （CNTs） from methane was reported recently. In the present article, with this type of catalyst, the impact of such experimental parameters as reaction temperature, reaction time, concentration of H2, flow rate ratio of CH4 to H2 on yield and graphitization were investigated, leading to the following optimal growth conditions： reaction time 60min, reaction temperature 900℃, CH4：H2 about 100：20mL/min, under which high-yield multi-walled CNTs bundles were synthesized. Raman measurement indicated that the as-synthesized product was well-graphitized, and the purity was estimated over 95% by TG-DSC analysis. In terms of the above results, an explanation of high-efficiency formation of CNTs bundles and the co-catalysis mechanism of Ni-Mo/MgO were suggested. 2007 Chinese Societv of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.展开更多
In the process of printing and copying,the volatilization of toner produces tiny particles and harmful gases that are detrimental to the human body.Low-temperature printing and copying can reduce harmful gas emissions...In the process of printing and copying,the volatilization of toner produces tiny particles and harmful gases that are detrimental to the human body.Low-temperature printing and copying can reduce harmful gas emissions.Styrene acrylic resin is the main component of toner and the thermal conductivity of toner can be improved by increasing the thermal conductivity of styrene acrylic resin.In this paper,hexagonal boron nitride(h-BN),carboxyl modified multi-walled carbon nanotubes(MWCNTs-COOH)and graphene hybrid fillers were added into styrene acrylic resin to improve the thermal conductivity of resin composite by forming a connected thermal conductivity network in resin.The experimental result shows that the thermal conductivity of the h-BN/styrene acrylic resin composite increases with the increase in h-BN filler content(0-20wt%).When 20.0 wt%h-BN is added into styrene acrylic resin,the thermal conductivity is increased by 83.63%.Hybrid fillers(MWCNTs-COOH/graphene and 3.0 wt%h-BN)were added in styrene acrylic resin and the thermal conductivity of the composite is almost the same or higher than that of 20.0 wt%h-BN/styrene acrylic resin composite.The thermal conductivity of styrene acrylic resin composites improved by 69.57%and 87.14%via adding 1.5wt%CNTs-3 wt%h-BN and 1.0wt%graphene-3 wt%h-BN.MWCNTs-COOH or graphene can bridge isolated h-BN aggregates to form a thermally conductive network in styrene acrylic resin,while the addition of graphene improves the thermal conductivity of resin composite higher than that of MWCNTs-COOH.展开更多
基金financially supported by National Natural Science Foundation of China(Grant.22076189)National Key Research and Development Program of China(No.2023YFC3707003)the Joint Fund of Yulin University and Dalian National Laboratory for Clean Energy(Grant.YLU-DNL Fund 2022003).
文摘Blast furnace gas(BFG)is an important by-product energy for the iron and steel industry and has been widely used for heating or electricity generation.However,the undesirable contaminants in BFG(especially H_(2)S)generate harmful environmental emissions.The desulfurization of BFG is urgent for integrated steel plants due to the stringent ultra-low emission standards.Compared with other desulfurization materials,zeolite-based adsorbents represent a viable option with low costs and long service life.In this study,an ammonia-induced CuO modified 13X adsorbent(NH_(3)–CuO/13X)was prepared for H_(2)S removal from simulated BFG at low temperature.The XRD,H_(2)-TPR and TEM analysis proved that smaller CuO particles were formed and the dispersion of Cu on the surface of 13X zeolite was improved via the induction of ammonia.Evaluation on H_(2)S adsorption performance of the adsorbent was carried out using simulated BFG,and the results showed that NH_(3)–CuO/13X-3 has better breakthrough sulfur capacity,which was more than twice the sulfur capacity of CuO/13X.It is proposed that the enhanced desulfurization performance of NH_(3)–CuO/13X is attributed to an abundant pore of 13X,and combined action of 13X and CuO.This work provided an effective way to improve the sulfur capacity of zeolite-based adsorbents via impregnation method by ammonia induction.
基金supported by the National Natural Science Foundation of China(U1908201,U1903130)the Ministry of Science and Technology of the People’s Republic of China(2020YFC1909300)the Natural Science Foundation of Liaoning Province of China(2021-NLTS-12-09).
文摘Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.
基金supported by the National Key Research and Development Program of China(grant No.2022YFC3701900)the National Natural Science Foundation of China(grant No.22278423,U21A20316)the Science Foundation of China University of Petroleum,Beijing(grant No.2462021QNXZ007).
文摘Water pollution caused by organic dyes is a critical environmental issue.Although activated carbon(AC)is commonly used for dye adsorption,its effectiveness is limited by challenges in separation and regeneration.To address these limitations,a convenient recyclable magnetic activated carbon(MAC)was fabricated via co-precipitation and calcination method,serving as adsorbent and catalyst for methyl orange(MO)removal through a Fenton-like degradation process.Characterization techniques,including XRD,FTIR,SEM and TEM,confirmed that Fe_(3)O_(4) nanoparticles(10–20 nm)were uniformly dispersed on AC surface.The MAC maintaining a high surface area(997 m^(2)/g)and pore volume(0.795 cm^(3)/g)and exhibited superparamagnetic properties with a saturated magnetization of 5.52 emu/g,enabling effective separation from aqueous solutions by magnet.Batch adsorption studies revealed that MO adsorption onto MAC followed pseudo-second-order kinetic and Freundlich isotherm model,with a maximum adsorption capacity of 205 mg/g at 25℃.Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic.Simultaneous degradation of MO and in-situ regeneration of MAC were achieved via Fenton-like reaction using sodium persulfate(PS).Under a PS concentration of 9 mmol/L,the MO removal efficiency near 95%after 60 min,with a total organic carbon(TOC)reduction of 83.1%.The reaction of Fe_(3)O_(4) and oxygen functional groups on AC surface with PS facilitated the generation of SO_(4)^(·-),thereby enhancing catalytic degradation of MO.The degradation efficiency improved as the temperature increased from 25℃ to 45℃.Cycle tests demonstrated that the MO removal efficiency of MAC remained above 90%after 5 cycles of regeneration.Overall,this study highlights the potential of MAC for efficient removal of organic dyes from water through the coupling of adsorption and Fenton-like degradation,providing a promising solution for addressing water pollution challenges.
文摘Nickel cobalt sulfides (MCo2S4) have attracted considerable attention as electrode materials for supercapacitors. Herein, a sea-urchin-like NiCo2S4 material was synthesized through a one-step solvothermal process. Polyethylene glycol (PEG) 200 and thiourea were used as a shape-control age nt and sulfur source for in-s让u sulfuration, respectively. The urchin-like NiC02S4 was characterized by X-ray powder diffraction, scanning electron microscopy, Brunauer-Emmett-Teller surface area, and electrochemical measurements. The resulting NiCo2S4 with ion diffusion-favored structure demonstrated remarkable electrochemical characteristics for supercapacitor with a high specific capacitance (1334F/g at 0.5 A/g) and superior rate capability (78.1% of the original capacity from 0.5 to 20 A/g) in 6M KOH aqueous solution. Furthermore, an asymmetric supercapacitor was assembled using NiCo2S4 as a positive electrode and activated carb on (AC) as a n egative electrode. A NiCo2Sj/AC device exhibited a high energy density of 37.32 Wh/kg at a power density of 317.8 W/kg with capacity retention of 91.9% and up to 2000 charge/discharge cycles at 3 A/g. The results demonstrate that the sea-urchin-like NiCo2S4 has potential applications in supercapacitors.
基金the Fund of National Key Research and Development Projects(Intergovernmental International Cooperation in Science and Technology Innovation Program,No.2018YFE0103400),China.
文摘A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on reaction mechanisms and thermodynamics have revealed that the OCM process is highly exothermic and its C2+selectivity and yield is critical in evaluating its commercial viability.Catalytic strategies have been put to enhance C2+selectivity,improve C2+yield and lower reaction temperature.The catalyst MnNa2WO4/SiO2 enables methane activation at a temperature of 800◦C and simultaneously a high C2+selectivity of 70–80%,while the nanowire and La2O3-based catalysts enable to lower the reaction temperature to 200–300◦C and 500◦C,respectively.Reaction engineering aspects have also been dealt in many investigations in order to make the process technically feasible.Particularly,research works on reaction kinetics,reactor selection and reactor operating mode choice have been addressed.Intermediate cooling and distributed oxygen feed have been integrated into a multi-stage adiabatic fixed-bed reactor system to suppress the side oxidation reactions and improve the performance of the catalysts towards CH4 conversion and C2+yield.This review paper proposes employing a circulating reactor system coupled with catalyst fine particles but having little internal diffusion resistance to maximize one-pass C2+selectivity and yield of the OCM reaction and evaluate its industrial application potential.
基金the financial support provide by the National Key Research and Development Program(No.2016YFB0600404-02).
文摘To utilize low rank coal efficiently,a fluidized bed two-stage(FBTS)gasification process,mainly consisting of a FB pyrolyzer and a transport FB(TFB)gasifier,has been proposed for the production of clean fuel gas.To verify the feasibility and technical features of this novel gasification technology,a pilot autothermal platform,with a treating capacity of 100 kg/h for coal,was designed and built up.By adopting a kind of lignite from Inner Mongolia,the running state and fuel gas quality were compared systematically under typical operational conditions.The results show that by keeping the reaction temperatures of pyrolyzer and gasifier at around 840C and 1000C,respectively,the corresponding tar content in fuel gas at the outlets of pyrolyzer and gasifier were 1127 mg/Nm3 and 365 mg/Nm3,reaching a high tar removal efficiency.Under the stable operation state,the volume fractions of CO,H2,CH4 and CO2 in fuel gas were 14.4%,8.3%,3.4%and 11.3%,respectively,and the corresponding higher heating value of fuel gas was about 1100 kcal/Nm3.Compared with the tar from pyrolyzer,the heavy oil fraction in tar from gasifier reduced significantly,while the light oil components increased sharply simultaneously,showing significant effect of catalytic reforming by hot char bed on tar removal.
基金the Fund of State Key Laboratory of Multiphase Complex Systems(No.MPCS-2019-A-03)Center for Mesoscience(No.COM2016A003)Institute of Process Engineering,and DNL Cooperation Fund(No.DNL180304),Chinese Academy of Sciences.
文摘Owing to high thermal conductivity,carbon nanotube and graphene have been used as nanofillers to improve the thermal conductivity of polymer.However,the agglomeration of nanofillers in polymer inhibits their applications in improving the thermal conductivity of composite.To overcome this problem,graphene was grown on Ni foam by chemical vapor deposition in this work.And graphene-nickel three-dimensional filler was added into epoxy resin to improve the thermal conductivity of epoxy resin.Ni foam can prevent the agglomeration of graphene in epoxy resin and a thermally conductive network by graphene and Ni foam was formed in epoxy resin.By adding graphene-nickel three-dimensional filler into epoxy resin,the thermal conductivity of graphene-nickel/epoxy composite can reach up to 2.6549 W⋅m^(-1)⋅k^(-1),which was 9 times higher than that of raw epoxy resin.
基金This work was supported by the Fund of State Key Laboratory of Multiphase Complex System(No.MPCS-2021-A-12),Institute of Process Engineering,Chinese Academy of Sciences.
文摘In the present work,nanoporous carbon(NPC)was prepared from a metal-organic framework(zeolite imidazolate framework 8,ZIF-8).Different concentrations of graphene oxide(GO)were used to make NPC/reduced graphene oxide(NPC/rGO-x,x=0.5,1.0,1.5,and 2.0)composites,and thenγ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique.The electrochemical characteristics of porous carbon composites(NPC/rGO-x)andγ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge,cyclic voltammetry,and electrochemical impedance spectroscopy.NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g.Also,theγ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70%capacitance retention after 10,000 cycles at 1 A/g.As a result,this study demonstrates thatγ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.
基金This work was supported financially by the National Natural Science Foundation of China （No. 20506010） Beijing Novel Program （2006A74）Natural Science Fund of Shanxi Province （No. 20063004）.
文摘A new dual-composition catalyst based on Ni-Mo/MgO with high efficiency of producing carbon nanotubes （CNTs） from methane was reported recently. In the present article, with this type of catalyst, the impact of such experimental parameters as reaction temperature, reaction time, concentration of H2, flow rate ratio of CH4 to H2 on yield and graphitization were investigated, leading to the following optimal growth conditions： reaction time 60min, reaction temperature 900℃, CH4：H2 about 100：20mL/min, under which high-yield multi-walled CNTs bundles were synthesized. Raman measurement indicated that the as-synthesized product was well-graphitized, and the purity was estimated over 95% by TG-DSC analysis. In terms of the above results, an explanation of high-efficiency formation of CNTs bundles and the co-catalysis mechanism of Ni-Mo/MgO were suggested. 2007 Chinese Societv of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.
基金supported by National Key Research and Development Projects(Intergovernmental International Cooperation in Science and Technology Innovation Program,No.2018YFE0103400),China.
文摘In the process of printing and copying,the volatilization of toner produces tiny particles and harmful gases that are detrimental to the human body.Low-temperature printing and copying can reduce harmful gas emissions.Styrene acrylic resin is the main component of toner and the thermal conductivity of toner can be improved by increasing the thermal conductivity of styrene acrylic resin.In this paper,hexagonal boron nitride(h-BN),carboxyl modified multi-walled carbon nanotubes(MWCNTs-COOH)and graphene hybrid fillers were added into styrene acrylic resin to improve the thermal conductivity of resin composite by forming a connected thermal conductivity network in resin.The experimental result shows that the thermal conductivity of the h-BN/styrene acrylic resin composite increases with the increase in h-BN filler content(0-20wt%).When 20.0 wt%h-BN is added into styrene acrylic resin,the thermal conductivity is increased by 83.63%.Hybrid fillers(MWCNTs-COOH/graphene and 3.0 wt%h-BN)were added in styrene acrylic resin and the thermal conductivity of the composite is almost the same or higher than that of 20.0 wt%h-BN/styrene acrylic resin composite.The thermal conductivity of styrene acrylic resin composites improved by 69.57%and 87.14%via adding 1.5wt%CNTs-3 wt%h-BN and 1.0wt%graphene-3 wt%h-BN.MWCNTs-COOH or graphene can bridge isolated h-BN aggregates to form a thermally conductive network in styrene acrylic resin,while the addition of graphene improves the thermal conductivity of resin composite higher than that of MWCNTs-COOH.
