A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a...A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a dense SrFe_(0.9)Ta_(0.1)O_(3-σ)(SFT)separation layer and a porous Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Cu_(0.1)O_(3-σ)(SFTC)catalytic layer.In thefirst stage reactor,a CO_(2) splitting reaction(CDS:2CO_(2)→2CO+O_(2))occurs at the SFTC catalytic layer.Subsequently,the O_(2) product is selectively extracted through the SFT separation layer to the permeated side for the methane combustion reaction(MCR),which provides an extremely low oxygen partial pressure to enhance the oxygen extraction.In the second stage,a Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Ni_(0.1)O_(3-σ)(SFTN)catalyst is employed to reform the products derived from MCR.The two-stage CMR design results in a remarkable 35.4%CO_(2) conversion for CDS at 900℃.The two-stage CMR was extended to a hollowfiber configuration combining with solar irradiation.The solar-assisted two-stage CMR can operate stably for over 50 h with a high hydrogen yield of 18.1 mL min^(-1) cm^(-2).These results provide a novel strategy for reducing CO_(2) emissions,suggesting potential avenues for the design of the high-performance CMRs and catalysts based on perovskite oxides in the future.展开更多
In this study, catalytic wet air oxidation of wastewater that contains organic matter (phenol) is investigated in a laboratory scale trickle-bed reactor. The aim of this project is to determine the optimum operating c...In this study, catalytic wet air oxidation of wastewater that contains organic matter (phenol) is investigated in a laboratory scale trickle-bed reactor. The aim of this project is to determine the optimum operating conditions for the reaction of phenol in the wastewater with oxygen using a catalyst. For this purpose, the effects of temperature, gas flow rate, liquid space velocity and initial concentration of phenol on the conversion of phenol at constant pressure and the effect of pressure on the conversion of phenol at constant temperature are investigated. An industrial copper chromite catalyst was used in the experimental studies. It is seen from the experimental results, conversion of phenol increases with increasing temperature, pressure, gas flow rate and liquid space velocity;and also, it is seen that conversion of phenol decreases with increasing initial concentration of phenol. The conversion of phenol reaches at 130?C and 4 bar to 40%. It was also found that, 3 ppm copper amount was determined from the exit stream of the reactor. This result shows that cupper placed in the structure of the catalyst, mixes with the liquid stream during the reaction.展开更多
The manufacture,physical characterization,environmental applications and cytotoxicity properties of nanocomposites consisting of CuO/CeO2 nano-rare earth composite materials prepared using the coprecipitation method a...The manufacture,physical characterization,environmental applications and cytotoxicity properties of nanocomposites consisting of CuO/CeO2 nano-rare earth composite materials prepared using the coprecipitation method at molar ratio of 6:4 with aqueous solutions of copper nitrate and cerium nitrate were reported.The performance of the selective catalytic oxidation of ammonia to N2(NH3-SCO) over a CuO/CeO2 nano-rare earth composite materials in a tubular fixed-bed reactor(TFBR) at temperatures from 423 to 673 K in the presence of oxygen was elucidated.The catalytic redox behavior was determined by cyclic voltammetry(CV).The nanocomposite particles were characterized by TEM,with a tiny particle size around 10 nm with high dispersion phenomena.Further,cell cytotoxicity and the percentage cell survival were determined by using 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetra-zolium(MTS) assay on human lung MRC-5 cell line.Experimental results showed that no apparent cytotoxicity was observed when the MRC-5 was exposed to the CuO/CeO2 nanocomposite materials.展开更多
The oxidative coupling of methane （OCM） to ethylene over a perovskite titanate catalyst in a fixed bed reactor was studied experimentally and numerically. The two-dimensional steady state model accounted for separat...The oxidative coupling of methane （OCM） to ethylene over a perovskite titanate catalyst in a fixed bed reactor was studied experimentally and numerically. The two-dimensional steady state model accounted for separate energy equations for the gas and solid phases coupled with an experimental kinetic model. A lumped kinetic model containing four main species CH4, O2, COx （CO2, CO）, and C2 （C2H4 and C2H6） was used with a plug flow reactor model as well. The results from the model agreed with the experimental data. The model was used to analyze the influence of temperature and feed gas composition on the conversion and selectivity of the reactor performance. The analytical results indicate that the conversion decreases, whereas, C2 selectivity increases by increasing gas hourly space velocity （GHSV） and the methane conversion also decreases by increasing the methane to oxygen ratio.展开更多
Catalytic ozonation technology has attracted copious attention in water purification owing to its favorable oxidative degradation of pollutants and mitigation of membrane fouling capacity.However,its extensive industr...Catalytic ozonation technology has attracted copious attention in water purification owing to its favorable oxidative degradation of pollutants and mitigation of membrane fouling capacity.However,its extensive industrial application has been restricted by the low ozone utilization and limited mass transfer of the short-lived radical species.Interlayer space-confined catalysis has been theoretically proven to be a viable strategy for achieving high catalytic efficiency.Here,a two-dimensional MnO_(2)-incorporated ceramic membrane with tunable interspacing,which was obtained via the intercalation of a carbon nanotube,was designed as a catalytic ozonation membrane reactor for degrading methylene blue.Benefiting from the abundant catalytic active sites on the surface of two-dimensional MnO_(2) as well as the ultralow mass transfer resistance of fluids due to the nanolayer confinement,an excellent mineralization effect,i.e.,1.2 mg O_(3)(aq)mg^(-1) TOC removal(a total organic carbon removal rate of 71.5%),was achieved within a hydraulic retention time of 0.045 s of pollutant degradation.Further,the effects of hydraulic retention time and interlayer spacing on methylene blue removal were investigated.Moreover,the mechanism of the catalytic ozonation employing catalytic ozonation membrane was proposed based on the contribution of the Mn(III/IV)redox pair to electron transfer to generate the reactive oxygen species.This innovative twodimensional confinement catalytic ozonation membrane could act as a nanoreactor and separator to efficiently oxidize organic pollutants and enhance the control of membrane fouling during water purification.展开更多
基金supported by the National Key Research and Development Program of China(2022YFE0101600)the National Natural Science Foundation of China(U23A20117)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20220002,BE2022024)the Leading Talents Program of Zhejiang Province(2024C03223)Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP).
文摘A two-stage catalytic membrane reactor(CMR)that couples CO_(2) splitting with methane oxidation reactions was constructed based on an oxygen-permeable perovskite asymmetric membrane.The asymmetric membrane comprises a dense SrFe_(0.9)Ta_(0.1)O_(3-σ)(SFT)separation layer and a porous Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Cu_(0.1)O_(3-σ)(SFTC)catalytic layer.In thefirst stage reactor,a CO_(2) splitting reaction(CDS:2CO_(2)→2CO+O_(2))occurs at the SFTC catalytic layer.Subsequently,the O_(2) product is selectively extracted through the SFT separation layer to the permeated side for the methane combustion reaction(MCR),which provides an extremely low oxygen partial pressure to enhance the oxygen extraction.In the second stage,a Sr_(0.9)(Fe_(0.9)Ta_(0.1))_(0.9)Ni_(0.1)O_(3-σ)(SFTN)catalyst is employed to reform the products derived from MCR.The two-stage CMR design results in a remarkable 35.4%CO_(2) conversion for CDS at 900℃.The two-stage CMR was extended to a hollowfiber configuration combining with solar irradiation.The solar-assisted two-stage CMR can operate stably for over 50 h with a high hydrogen yield of 18.1 mL min^(-1) cm^(-2).These results provide a novel strategy for reducing CO_(2) emissions,suggesting potential avenues for the design of the high-performance CMRs and catalysts based on perovskite oxides in the future.
文摘In this study, catalytic wet air oxidation of wastewater that contains organic matter (phenol) is investigated in a laboratory scale trickle-bed reactor. The aim of this project is to determine the optimum operating conditions for the reaction of phenol in the wastewater with oxygen using a catalyst. For this purpose, the effects of temperature, gas flow rate, liquid space velocity and initial concentration of phenol on the conversion of phenol at constant pressure and the effect of pressure on the conversion of phenol at constant temperature are investigated. An industrial copper chromite catalyst was used in the experimental studies. It is seen from the experimental results, conversion of phenol increases with increasing temperature, pressure, gas flow rate and liquid space velocity;and also, it is seen that conversion of phenol decreases with increasing initial concentration of phenol. The conversion of phenol reaches at 130?C and 4 bar to 40%. It was also found that, 3 ppm copper amount was determined from the exit stream of the reactor. This result shows that cupper placed in the structure of the catalyst, mixes with the liquid stream during the reaction.
基金Project partially supported by the National Science Council of the Republic of China Taiwan (NSC 98-2221-E-132-003-MY3)
文摘The manufacture,physical characterization,environmental applications and cytotoxicity properties of nanocomposites consisting of CuO/CeO2 nano-rare earth composite materials prepared using the coprecipitation method at molar ratio of 6:4 with aqueous solutions of copper nitrate and cerium nitrate were reported.The performance of the selective catalytic oxidation of ammonia to N2(NH3-SCO) over a CuO/CeO2 nano-rare earth composite materials in a tubular fixed-bed reactor(TFBR) at temperatures from 423 to 673 K in the presence of oxygen was elucidated.The catalytic redox behavior was determined by cyclic voltammetry(CV).The nanocomposite particles were characterized by TEM,with a tiny particle size around 10 nm with high dispersion phenomena.Further,cell cytotoxicity and the percentage cell survival were determined by using 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetra-zolium(MTS) assay on human lung MRC-5 cell line.Experimental results showed that no apparent cytotoxicity was observed when the MRC-5 was exposed to the CuO/CeO2 nanocomposite materials.
文摘The oxidative coupling of methane （OCM） to ethylene over a perovskite titanate catalyst in a fixed bed reactor was studied experimentally and numerically. The two-dimensional steady state model accounted for separate energy equations for the gas and solid phases coupled with an experimental kinetic model. A lumped kinetic model containing four main species CH4, O2, COx （CO2, CO）, and C2 （C2H4 and C2H6） was used with a plug flow reactor model as well. The results from the model agreed with the experimental data. The model was used to analyze the influence of temperature and feed gas composition on the conversion and selectivity of the reactor performance. The analytical results indicate that the conversion decreases, whereas, C2 selectivity increases by increasing gas hourly space velocity （GHSV） and the methane conversion also decreases by increasing the methane to oxygen ratio.
基金supported by the National Natural Science Foundation of China(Grant Nos.21838005 and 21676139)the Key Scientific Research and Development Projects of Jiangsu Province(Grant No.BE201800901)。
文摘Catalytic ozonation technology has attracted copious attention in water purification owing to its favorable oxidative degradation of pollutants and mitigation of membrane fouling capacity.However,its extensive industrial application has been restricted by the low ozone utilization and limited mass transfer of the short-lived radical species.Interlayer space-confined catalysis has been theoretically proven to be a viable strategy for achieving high catalytic efficiency.Here,a two-dimensional MnO_(2)-incorporated ceramic membrane with tunable interspacing,which was obtained via the intercalation of a carbon nanotube,was designed as a catalytic ozonation membrane reactor for degrading methylene blue.Benefiting from the abundant catalytic active sites on the surface of two-dimensional MnO_(2) as well as the ultralow mass transfer resistance of fluids due to the nanolayer confinement,an excellent mineralization effect,i.e.,1.2 mg O_(3)(aq)mg^(-1) TOC removal(a total organic carbon removal rate of 71.5%),was achieved within a hydraulic retention time of 0.045 s of pollutant degradation.Further,the effects of hydraulic retention time and interlayer spacing on methylene blue removal were investigated.Moreover,the mechanism of the catalytic ozonation employing catalytic ozonation membrane was proposed based on the contribution of the Mn(III/IV)redox pair to electron transfer to generate the reactive oxygen species.This innovative twodimensional confinement catalytic ozonation membrane could act as a nanoreactor and separator to efficiently oxidize organic pollutants and enhance the control of membrane fouling during water purification.
