The effective utilization of natural gas resources is a promising option for the implementation of the"dual carbon"strategy.However,the capture of carbon dioxide with relatively lower concentration after the...The effective utilization of natural gas resources is a promising option for the implementation of the"dual carbon"strategy.However,the capture of carbon dioxide with relatively lower concentration after the combustion of natural gas is the crucial step.Fortunately,the lattice oxygen is used for chemical cycle conversion of methane to overcome the shortcomings mentioned above.A method was proposed to synthesize perovskite for methane cycle conversion using metal organic framework as a precursor.Morphology and pore structure of Fe_(2)O_(3)-LaFeO_(3)composite oxides were regulated by precursor synthesis conditions and calcination process.Moreover,the chemical looping conversion performance of methane was evaluated.The results showed that the pure phase precursor of La[Fe(CN)_(6)]·5H_(2)O was synthesized with the specific surface area of 23.91 m^(2)·g^(-1)under the crystallization of 10 h and the pH value of10.5.Fe_(2)O_(3)-LaFeO_(3)was obtained by controlled calcination of La[Fe(CN)_(6)]·5H_(2)O and Fe_(2)O_(3)with variable mass ratio.The selectivity of CO_(2)can reach more than 99%under the optimal parameters of methane chemical looping conversion:m(Fe_(2)O_(3)):m(LaFeO_(3))=2:1,the reaction temperature is 900℃,the lattice oxygen conversion is less than 40%.Fe_(2)O_(3)-LaFeO_(3)still has good phase and structure stability after five redox reaction and regeneration cycles.展开更多
To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that ...To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites.Furthermore,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of p-nitrophenol.The density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized adsorbent.Both NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites.Among the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1).展开更多
A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the so...A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.展开更多
A new method for regulating the synthesis of Ni Mg Fe hydrotalcites(NMF LDHs) with the addition of hydroxyl compounds was proposed. A series of NMF LDHs were prepared by the above method, and then were calcined to obt...A new method for regulating the synthesis of Ni Mg Fe hydrotalcites(NMF LDHs) with the addition of hydroxyl compounds was proposed. A series of NMF LDHs were prepared by the above method, and then were calcined to obtain the Ni Mg FeOx(NMFOx) samples. The NMFOxsamples were characterized by XRD,SEM, TG-DTG, XPS and CO2-TPD, respectively. The catalytic performance of NMFOxfor depolymerizing calcium lignosulfonate(CLS) was evaluated by hydrothermal reaction. The results showed that the addition of hydroxyl compounds favored reducing the particle sizes of NMF LDHs. For the depolymerization of CSL, the yield of liquid product increased from 45% to 75.8% with the addition of NMFOx-ethanol(NMFOxET). The liquid products were mainly phenolics, aromatics, ketones and esters. The total selectivity of oxy-containing compounds was over 90.6%, among them, the phenolics were approximately 35.2%. The valence of Ni and Fe, crystalline phase and basicity almost remained unchanged. The NMFOx-ET samples were recycled for the depolymerization of CLS, moreover, the NMFOx-ET samples had high activity and stability after 4 cycles.展开更多
Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization(HDS) were synthesized by two different phosphorus sources, in which the surface of Ni_2P catalysts were modified by air instead of bei...Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization(HDS) were synthesized by two different phosphorus sources, in which the surface of Ni_2P catalysts were modified by air instead of being passivated by O_2/N_2 mixture. In addition, the catalysts need not be activated with flowing H_2(30 ml·min^(-1))at 500 °C for 2 h prior to reaction as traditional method. X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), N_2-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni_2P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K, the dibenzothiophene(DBT)conversion of the catalysts modified with air was 98.7%, which was 7.1% higher than that of catalyst passivated by O_2/N_2 mixture. The higher activities of Ni_2P(x)/M41-O catalysts can be attributed to the smaller Ni_2P particles sizes and the increased hydrogen dissociation activity due to the surface modification.展开更多
To realize the resource and high-value utilization,a new approach,named bagasse lignin(BL) used to produce aryl oxygen-containing compounds by catalytic pyrolysis over perovskite,was proposed,LaTi0.2Fe0.8O3(LTF) sampl...To realize the resource and high-value utilization,a new approach,named bagasse lignin(BL) used to produce aryl oxygen-containing compounds by catalytic pyrolysis over perovskite,was proposed,LaTi0.2Fe0.8O3(LTF) samples prepared by the sol-gel method(SG) and the solid-state reaction method(SS)were characterized.The catalytic action on BL pyrolysis was performed by the test of TG-DTG and the evaluation of the fixed bed micro-reactor,the components and contents of the products were determined.The results show that LTF samples have cubic perovskite phase,LTF prepared by SG(LTF-SG) is porous with larger specific surface area than LTF prepared by SS(LTF-SS).During the pyrolysis of BL,the addition of LTF lowers the pyrolysis temperature and the activation energy,the contents of CO2 and CO in gaseous products reduce by 4.6%-8.0% and 30.7%-34.3%,respectively,the total content of aryl oxygencontaining compounds(including phenolics,guaiacols,syringols and phenylates) in liquid products increases from 62 wt% to more than 72 wt%,and LTF-SG shows better catalytic performance.LTF samples have nice phase and catalytic stabilities for BL pyrolysis after five successive redox cycles.展开更多
LaTi(0.2)Fe(0.8)O3(LTF)was prepared by the sol-gel method,and the effects of calcination temperature on the structure and properties were investigated,A new method of preparing aryl oxygen-containing compounds from ba...LaTi(0.2)Fe(0.8)O3(LTF)was prepared by the sol-gel method,and the effects of calcination temperature on the structure and properties were investigated,A new method of preparing aryl oxygen-containing compounds from bagasse lignin(BL)by the catalytic pyrolysis over LTF was proposed.The results show that LTF has cubic crystal phase and porous structure and its optimal calcination temperature is 800℃(LTF-800).In the test for catalytic pyrolysis of BL,with the addition of LTF-800,the yield of liquid product reaches the maximum;the contents of phenolics,guaiacols,syringols,phenylates and furans increase obviously,while those of benzenes,esters and carboxylic acid decrease.The total content of aryl oxygencompounds(including phenolics,guaiacols,syringols and phenylates)in liquid product is more than 74 wt%with the addition of LTF-800,larger than that obtained by single BL pyrolysis(62 wt%).LTF could avoid oxygen-containing functional groups from being excessively destroyed.It has nice regeneration performance by controlled combustion of char even after 5 cycles.展开更多
Herein,sodium dodecylbenzene sulfonate(SDBS)was used as a template to control the synthesis of Ca_(0.5)Pr_(0.5)FeO_(3).Its microstructure,composition,and morphology were detected via X-ray diffraction(XRD),Fourier tra...Herein,sodium dodecylbenzene sulfonate(SDBS)was used as a template to control the synthesis of Ca_(0.5)Pr_(0.5)FeO_(3).Its microstructure,composition,and morphology were detected via X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),and scanning electron microscopy(SEM).The properties of catalyzing bagasse lignin(BL)pyrolysis were determined by thermogravimetric analysis(TG)test and evaluation of a fixed bed alumina microreactor.The results show that the sample Ca_(0.5)Pr_(0.5)FeO_(3)regulated by SDBS has a cubic crystal phase,and the addition of SDBS does not cause phase transition.Moreover,when the SDBS concentration is 0.10 mol/L,the particle size is 200-500 nm and the specific surface area is 11.26 m^(2)/g.The yields of gas,liquid,and solid products in the BL catalytic pyrolysis are 39.58 wt%,26.76 wt%and 32.36 wt%,respectively.The contents of CO_(2)and CO decrease from 54.07%and 4.98%to 45.29%and 3.23%,respectively.The liquid products are mainly guaiacol,syringol,and phenol,and the total selectivity of phenols is 83.67%,accompanied by a small amount of non-aromatic oxygen-containing compounds(five-membered ring(furan)or ester).Compared with the BL pyrolysis and Ca_(0.5)Pr_(0.5)FeO_(3)catalytic pyrolysis products,the selectivity of guaiacol compounds increases by43.26%,while those of syringol compounds and phenylketones decrease by 30.08%and 3.39%,respectively.The selectivity of 2,6-dimethoxyphenol is 28.37%.After five catalytic pyrolysis-regeneration cycles,the characteristic peaks of the catalyst do not change significantly and the particles are uniform,suggesting that the catalyst has good crystal phase stability and regeneration stability.展开更多
基金supported by the National Natural Science Foundation of China(21908021)the China Petroleum Science and Technology Innovation Fund project(2021DQ020701)+2 种基金the High-Level Talent Project of Heilongjiang Province of China(2020GSP17)the New Energy and New Direction Project of Northeast Petroleum University(XNYXLY202102)the Guiding Innovation Fund of Northeast Petroleum University(2021YDL03).
文摘The effective utilization of natural gas resources is a promising option for the implementation of the"dual carbon"strategy.However,the capture of carbon dioxide with relatively lower concentration after the combustion of natural gas is the crucial step.Fortunately,the lattice oxygen is used for chemical cycle conversion of methane to overcome the shortcomings mentioned above.A method was proposed to synthesize perovskite for methane cycle conversion using metal organic framework as a precursor.Morphology and pore structure of Fe_(2)O_(3)-LaFeO_(3)composite oxides were regulated by precursor synthesis conditions and calcination process.Moreover,the chemical looping conversion performance of methane was evaluated.The results showed that the pure phase precursor of La[Fe(CN)_(6)]·5H_(2)O was synthesized with the specific surface area of 23.91 m^(2)·g^(-1)under the crystallization of 10 h and the pH value of10.5.Fe_(2)O_(3)-LaFeO_(3)was obtained by controlled calcination of La[Fe(CN)_(6)]·5H_(2)O and Fe_(2)O_(3)with variable mass ratio.The selectivity of CO_(2)can reach more than 99%under the optimal parameters of methane chemical looping conversion:m(Fe_(2)O_(3)):m(LaFeO_(3))=2:1,the reaction temperature is 900℃,the lattice oxygen conversion is less than 40%.Fe_(2)O_(3)-LaFeO_(3)still has good phase and structure stability after five redox reaction and regeneration cycles.
基金supported by the National Natural Science Foundation of China(22008134)。
文摘To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites.Furthermore,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of p-nitrophenol.The density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized adsorbent.Both NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites.Among the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1).
基金Supported by the National Natural Science Foundation of China,China(51674089)Heilongjiang Provincial Science Fund for Distinguished Youth Scholar(JC2018002)+2 种基金Heilongjiang Postdoctoral Scientific Research Development Fund of China(LBH-Q16037)the Youth Fund of Northeast Petroleum University(2018QNL-17)Postgraduate Innovative Research Projects of Northeast Petroleum University(YJSCX2017-014NEPU)
文摘A new approach,named production of aryl oxygen-containing compounds from the catalytic pyrolysis of bagasse lignin(BL) over perovskite oxide,was proposed,A series of LaTixFe1-xO3(LTF-x) samples were prepared by the solid state reaction method.The crystal phase and morphology of LTF-x were characterized by XRD and SEM respectively.Catalytic pyrolysis performance of LTF-x was performed by TG-DTG and the distribution patterns of gaseous,liquid and solid products from BL was investigated using a fixed-bed micro-reactor.The optimal reaction conditions were determined:the pyrolysis temperature was 600℃,the mass ratio of mBL:mLTF-0.2 was 3:1,the veloeity of earrier gas was 100 ml·min-1.The gaseous produets were mainly eomposed of CO2,CO,CH4 and CnHm(n=2-4,m=2 n+2 or m=2 n),The main aryl oxygen-containing compounds in liquid products were phenolics,guaiacols,syringols and phenylates,the rest were benzenes,furans,esters and carboxylic acid.The total contents of aryl oxygencontaining compounds were from 62% up to more than 72% under the action of the perovskite.Moreover,the LTF-0.2 sample had nice regenerability.
基金Supported by the Program for National Natural Science Foundation of China(No.51674089)Excellent Youth Foundation of Heilongjiang Province of China(No.JC2018002)+2 种基金Postdoctoral Scientific Research Development Fund of Heilongjiang Province of China(No.LBH-Q16037)the Youth Fund of Northeast Petroleum University(No.2018QNL-17)the Postgraduate Innovative Research Projects of Northeast Petroleum University(No.YJSCX2017-014NEPU)
文摘A new method for regulating the synthesis of Ni Mg Fe hydrotalcites(NMF LDHs) with the addition of hydroxyl compounds was proposed. A series of NMF LDHs were prepared by the above method, and then were calcined to obtain the Ni Mg FeOx(NMFOx) samples. The NMFOxsamples were characterized by XRD,SEM, TG-DTG, XPS and CO2-TPD, respectively. The catalytic performance of NMFOxfor depolymerizing calcium lignosulfonate(CLS) was evaluated by hydrothermal reaction. The results showed that the addition of hydroxyl compounds favored reducing the particle sizes of NMF LDHs. For the depolymerization of CSL, the yield of liquid product increased from 45% to 75.8% with the addition of NMFOx-ethanol(NMFOxET). The liquid products were mainly phenolics, aromatics, ketones and esters. The total selectivity of oxy-containing compounds was over 90.6%, among them, the phenolics were approximately 35.2%. The valence of Ni and Fe, crystalline phase and basicity almost remained unchanged. The NMFOx-ET samples were recycled for the depolymerization of CLS, moreover, the NMFOx-ET samples had high activity and stability after 4 cycles.
基金Supported by the National Natural Science Foundation of China(21276048)the Project of Education Department of Heilongjiang Province,China(12541060)the Graduate Innovation Project of Northeast Petroleum University,China(YJSCX2016-019NEPU)
文摘Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization(HDS) were synthesized by two different phosphorus sources, in which the surface of Ni_2P catalysts were modified by air instead of being passivated by O_2/N_2 mixture. In addition, the catalysts need not be activated with flowing H_2(30 ml·min^(-1))at 500 °C for 2 h prior to reaction as traditional method. X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), N_2-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni_2P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K, the dibenzothiophene(DBT)conversion of the catalysts modified with air was 98.7%, which was 7.1% higher than that of catalyst passivated by O_2/N_2 mixture. The higher activities of Ni_2P(x)/M41-O catalysts can be attributed to the smaller Ni_2P particles sizes and the increased hydrogen dissociation activity due to the surface modification.
基金Project supported by National Natural Science Foundation of China(51674089)Heilongjiang Provincial Science Fund for Distinguished Youth Scholar(JC2018002)+2 种基金Postdoctoral Scientific Research Development Fund of Heilongjiang Province(LBH-Q16037)Postgraduate Innovative Research Project of Northeast Petroleum University(YJSCX2017-014NEPU)Youth Fund of Northeast Petroleum University(2018QNL-17)
文摘To realize the resource and high-value utilization,a new approach,named bagasse lignin(BL) used to produce aryl oxygen-containing compounds by catalytic pyrolysis over perovskite,was proposed,LaTi0.2Fe0.8O3(LTF) samples prepared by the sol-gel method(SG) and the solid-state reaction method(SS)were characterized.The catalytic action on BL pyrolysis was performed by the test of TG-DTG and the evaluation of the fixed bed micro-reactor,the components and contents of the products were determined.The results show that LTF samples have cubic perovskite phase,LTF prepared by SG(LTF-SG) is porous with larger specific surface area than LTF prepared by SS(LTF-SS).During the pyrolysis of BL,the addition of LTF lowers the pyrolysis temperature and the activation energy,the contents of CO2 and CO in gaseous products reduce by 4.6%-8.0% and 30.7%-34.3%,respectively,the total content of aryl oxygencontaining compounds(including phenolics,guaiacols,syringols and phenylates) in liquid products increases from 62 wt% to more than 72 wt%,and LTF-SG shows better catalytic performance.LTF samples have nice phase and catalytic stabilities for BL pyrolysis after five successive redox cycles.
基金Project supported by the National Natural Science Foundation of China(51674089)Heilongjiang Provincial Science Fund for Distinguished Youth Scholar(JC2018002)+1 种基金Postdoctoral Scientific Research Development Fund of Heilongjiang Province(LBH-Q16037)Postgraduate Innovative Research Projects of Northeast Petroleum University(YJSCX2017-014NEPU)
文摘LaTi(0.2)Fe(0.8)O3(LTF)was prepared by the sol-gel method,and the effects of calcination temperature on the structure and properties were investigated,A new method of preparing aryl oxygen-containing compounds from bagasse lignin(BL)by the catalytic pyrolysis over LTF was proposed.The results show that LTF has cubic crystal phase and porous structure and its optimal calcination temperature is 800℃(LTF-800).In the test for catalytic pyrolysis of BL,with the addition of LTF-800,the yield of liquid product reaches the maximum;the contents of phenolics,guaiacols,syringols,phenylates and furans increase obviously,while those of benzenes,esters and carboxylic acid decrease.The total content of aryl oxygencompounds(including phenolics,guaiacols,syringols and phenylates)in liquid product is more than 74 wt%with the addition of LTF-800,larger than that obtained by single BL pyrolysis(62 wt%).LTF could avoid oxygen-containing functional groups from being excessively destroyed.It has nice regeneration performance by controlled combustion of char even after 5 cycles.
基金Project supported by the National Natural Science Foundation of China(21908021)the Excellent Youth Foundation of Heilongjiang Province,China(JC2018002)the Youth Fund of Northeast Petroleum University(2018QNL-17)。
文摘Herein,sodium dodecylbenzene sulfonate(SDBS)was used as a template to control the synthesis of Ca_(0.5)Pr_(0.5)FeO_(3).Its microstructure,composition,and morphology were detected via X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),and scanning electron microscopy(SEM).The properties of catalyzing bagasse lignin(BL)pyrolysis were determined by thermogravimetric analysis(TG)test and evaluation of a fixed bed alumina microreactor.The results show that the sample Ca_(0.5)Pr_(0.5)FeO_(3)regulated by SDBS has a cubic crystal phase,and the addition of SDBS does not cause phase transition.Moreover,when the SDBS concentration is 0.10 mol/L,the particle size is 200-500 nm and the specific surface area is 11.26 m^(2)/g.The yields of gas,liquid,and solid products in the BL catalytic pyrolysis are 39.58 wt%,26.76 wt%and 32.36 wt%,respectively.The contents of CO_(2)and CO decrease from 54.07%and 4.98%to 45.29%and 3.23%,respectively.The liquid products are mainly guaiacol,syringol,and phenol,and the total selectivity of phenols is 83.67%,accompanied by a small amount of non-aromatic oxygen-containing compounds(five-membered ring(furan)or ester).Compared with the BL pyrolysis and Ca_(0.5)Pr_(0.5)FeO_(3)catalytic pyrolysis products,the selectivity of guaiacol compounds increases by43.26%,while those of syringol compounds and phenylketones decrease by 30.08%and 3.39%,respectively.The selectivity of 2,6-dimethoxyphenol is 28.37%.After five catalytic pyrolysis-regeneration cycles,the characteristic peaks of the catalyst do not change significantly and the particles are uniform,suggesting that the catalyst has good crystal phase stability and regeneration stability.