Co–Mo catalysts applied on the hydrodesulfurization（HDS） for FCC gasoline were prepared with Zn–Al layered double hydroxides（LDHs） to improve their performances,and the effects of pore structures and acidity on ...Co–Mo catalysts applied on the hydrodesulfurization（HDS） for FCC gasoline were prepared with Zn–Al layered double hydroxides（LDHs） to improve their performances,and the effects of pore structures and acidity on HDS performances were studied in detail. A series of Zn–Al/LDHs samples with different pore structures and acidities are synthesized on the bases of co-precipitation of OH-,CO2-,Al3＋,and Zn2＋. The neutralization p H is a main factor to affect the pore structures and acidity of Zn–Al/LDHs,and a series of Zn–Al/LDHs with different pore structures and acidities are obtained. Based on the representative samples with different specific surface areas（SBET） and acidities,three Co Mo/LDHs catalysts were prepared,and their HDS performances were compared with traditional Co Mo/Al2O3 catalysts. The results indicated that catalysts prepared with high SBETpossessed high HDS activity,and Br？nsted acid sites could reduce the thiol content in the product to some extent. All the three catalysts prepared with LDHs displayed little lower HDS activity but higher selectivity than Co Mo/Al2O3,and could restrain the reactions of re-combination between olefin and H2 S which could be due to the existence of Br？nsted acid sites.展开更多
Based on the analysis of flow characteristics of the FCC riser feedstock injection zone, two novel feedstock injection structures are put forward. By investigating three flow parameters in the feedstock injection zone...Based on the analysis of flow characteristics of the FCC riser feedstock injection zone, two novel feedstock injection structures are put forward. By investigating three flow parameters in the feedstock injection zone under the three different structures (the traditional and the novel No. 1, No. 2 structures): the local density, the particle backmixng ratio, and the jet eigen-concentration, the flow feature under three structures were obtained. The experimental results demonstrate that the flow features under both proposed structures are obviously improved comparing with those under the traditional structure. Especially, the performance of the deflector-structured No. 2 is more desirable than that of No. 1.展开更多
Petroleum-based polycyclic aromatic hydrocarbons(PAHs),as by-products of petroleum,offer the advantages of abundant availability and high carbon content,making them ideal high-quality raw materials for the fabrication...Petroleum-based polycyclic aromatic hydrocarbons(PAHs),as by-products of petroleum,offer the advantages of abundant availability and high carbon content,making them ideal high-quality raw materials for the fabrication of carbon anode materials in lithium batteries(LIBs).This study presents a novel,dual-purpose strategy to fabricate hollow core–shell silicon-carbon composites(Si@Void@Cx)via the in-situ catalytic polycondensation of Fluid Catalytic Cracking(FCC)slurry.Unlike traditional synthesis routes employing metallic Lewis acids(e.g.,AlCl_(3),FeCl_(3)),silicon tetrachloride(SiCl_(4))was used as a cleaner,bifunctional catalyst that avoids metallic contamination while facilitating the precise polymerization of the carbon matrix.This approach not only circumvents the integration of heteroatoms via the catalyst,but also simplifies the process flow,reduces energy consumption,and contributes to a greener,sustainable technology by enhancing the high-value utilization of FCC,benefiting both resource conservation and environmental protection.The optimized composite(Si@Void@C1)delivers a robust electrochemical performance,exhibiting a specific capacity of 601.9 mAh/g and maintaining electrode integrity with a negligible thickness expansion of only 7%after 1000 cycles.Si@Void@C1 capitalizes on the well-dispersed silicon(Si)nanoparticles and the intact hollow core–shell structure to effectively buffer against the volume expansion stress of Si,thus maintaining electrode structural integrity and achieving superior cycling performance.This work provides a scalable,sustainable pathway for transforming petrochemical byproducts into advanced energy storage materials.展开更多
Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepare...Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepared ceramics exhibit a single cubic phase belonging to the Pm3 m space group.The high entropy is the driving force of the formation of single-phase ceramics.A larger entropy(ΔS_(mix)) and a negative enthalpy(ΔH_(mix)) are conducive to the formation of single-phase compounds.Herein,ΔS_(mix)=0.323 R mole-1andΔH_(mix)=43.88 kJ/mol.The sluggish-diffusion effect ensures the thermal stability of high-entropy systems.Dielectric measurements reveal that the as-prepared BTZSHC high-entropy ceramics are relaxor ferroelectrics,and the degree of relaxor(γ) is 1.9.The relaxor behavior of the as-prepared ceramics can be ascribed to the relaxation and thermal evolution of their polar units(PUs).The findings of this work provide a theoretical basis and technical support for the preparation of single-phase high-entropy ceramics.展开更多
Two types of lath structures and kinked ε martensite were observed in the high manganese non-magnetic steel.Both the short non-continuous lath formed by quenching and the long thin straight lath induced by plastic de...Two types of lath structures and kinked ε martensite were observed in the high manganese non-magnetic steel.Both the short non-continuous lath formed by quenching and the long thin straight lath induced by plastic deformation are composed of ε martensite and fcc twin. The transformation mechanism was discussed.The crystallographic analysis indicates that the e martensite at both sides of the fcc twin boundary is of kinked morphology owing to the orientation of their matrices differing from each other.The kinked region is hcp twin.展开更多
In the present work the research of grain boundary (CB) energy versus angle of misorientation in fcc metals Al, Cu, An and Ni was carried out. An axis of CB misorientation is a direction [100], angle of misorientatio...In the present work the research of grain boundary (CB) energy versus angle of misorientation in fcc metals Al, Cu, An and Ni was carried out. An axis of CB misorientation is a direction [100], angle of misorientation makes from 2皍p in 23*. The interatomic interaction was opproximated by Morse' s pair semi-empirical potential. Two variants of relaxation technique were used: (1) rigid relax- ation with the change of atom quantity per a GB (vacancy relaxation ) and (2) full atomic relaxation by a molecular static method. The obtained orientation dependence has a good agreement with experi- ment. There are cusps on a curve in the range of special GB angles.The comparison of obtained curves with calculated ones in model Van der Merwe was carried out. Dependencies obtained in our investiga- tions are not smooth and have an oscillatory character. The oscillations reflect a discrete structure of a lattice.展开更多
文摘Co–Mo catalysts applied on the hydrodesulfurization（HDS） for FCC gasoline were prepared with Zn–Al layered double hydroxides（LDHs） to improve their performances,and the effects of pore structures and acidity on HDS performances were studied in detail. A series of Zn–Al/LDHs samples with different pore structures and acidities are synthesized on the bases of co-precipitation of OH-,CO2-,Al3＋,and Zn2＋. The neutralization p H is a main factor to affect the pore structures and acidity of Zn–Al/LDHs,and a series of Zn–Al/LDHs with different pore structures and acidities are obtained. Based on the representative samples with different specific surface areas（SBET） and acidities,three Co Mo/LDHs catalysts were prepared,and their HDS performances were compared with traditional Co Mo/Al2O3 catalysts. The results indicated that catalysts prepared with high SBETpossessed high HDS activity,and Br？nsted acid sites could reduce the thiol content in the product to some extent. All the three catalysts prepared with LDHs displayed little lower HDS activity but higher selectivity than Co Mo/Al2O3,and could restrain the reactions of re-combination between olefin and H2 S which could be due to the existence of Br？nsted acid sites.
文摘Based on the analysis of flow characteristics of the FCC riser feedstock injection zone, two novel feedstock injection structures are put forward. By investigating three flow parameters in the feedstock injection zone under the three different structures (the traditional and the novel No. 1, No. 2 structures): the local density, the particle backmixng ratio, and the jet eigen-concentration, the flow feature under three structures were obtained. The experimental results demonstrate that the flow features under both proposed structures are obviously improved comparing with those under the traditional structure. Especially, the performance of the deflector-structured No. 2 is more desirable than that of No. 1.
基金financially supported by National Key Research and Development Program of China(2022YFB3504000)the National Natural Science Foundation of China(22508430).
文摘Petroleum-based polycyclic aromatic hydrocarbons(PAHs),as by-products of petroleum,offer the advantages of abundant availability and high carbon content,making them ideal high-quality raw materials for the fabrication of carbon anode materials in lithium batteries(LIBs).This study presents a novel,dual-purpose strategy to fabricate hollow core–shell silicon-carbon composites(Si@Void@Cx)via the in-situ catalytic polycondensation of Fluid Catalytic Cracking(FCC)slurry.Unlike traditional synthesis routes employing metallic Lewis acids(e.g.,AlCl_(3),FeCl_(3)),silicon tetrachloride(SiCl_(4))was used as a cleaner,bifunctional catalyst that avoids metallic contamination while facilitating the precise polymerization of the carbon matrix.This approach not only circumvents the integration of heteroatoms via the catalyst,but also simplifies the process flow,reduces energy consumption,and contributes to a greener,sustainable technology by enhancing the high-value utilization of FCC,benefiting both resource conservation and environmental protection.The optimized composite(Si@Void@C1)delivers a robust electrochemical performance,exhibiting a specific capacity of 601.9 mAh/g and maintaining electrode integrity with a negligible thickness expansion of only 7%after 1000 cycles.Si@Void@C1 capitalizes on the well-dispersed silicon(Si)nanoparticles and the intact hollow core–shell structure to effectively buffer against the volume expansion stress of Si,thus maintaining electrode structural integrity and achieving superior cycling performance.This work provides a scalable,sustainable pathway for transforming petrochemical byproducts into advanced energy storage materials.
基金financially supported by the National Natural Science Foundation of China (Nos.52102144,52172099)the Provincial Joint Fund of Shaanxi (No.2021JLM-28)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (No.2022JM-255)the Scientific Research Plan Projects of Shaanxi Education Department (No.19JK0525)。
文摘Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepared ceramics exhibit a single cubic phase belonging to the Pm3 m space group.The high entropy is the driving force of the formation of single-phase ceramics.A larger entropy(ΔS_(mix)) and a negative enthalpy(ΔH_(mix)) are conducive to the formation of single-phase compounds.Herein,ΔS_(mix)=0.323 R mole-1andΔH_(mix)=43.88 kJ/mol.The sluggish-diffusion effect ensures the thermal stability of high-entropy systems.Dielectric measurements reveal that the as-prepared BTZSHC high-entropy ceramics are relaxor ferroelectrics,and the degree of relaxor(γ) is 1.9.The relaxor behavior of the as-prepared ceramics can be ascribed to the relaxation and thermal evolution of their polar units(PUs).The findings of this work provide a theoretical basis and technical support for the preparation of single-phase high-entropy ceramics.
文摘Two types of lath structures and kinked ε martensite were observed in the high manganese non-magnetic steel.Both the short non-continuous lath formed by quenching and the long thin straight lath induced by plastic deformation are composed of ε martensite and fcc twin. The transformation mechanism was discussed.The crystallographic analysis indicates that the e martensite at both sides of the fcc twin boundary is of kinked morphology owing to the orientation of their matrices differing from each other.The kinked region is hcp twin.
文摘In the present work the research of grain boundary (CB) energy versus angle of misorientation in fcc metals Al, Cu, An and Ni was carried out. An axis of CB misorientation is a direction [100], angle of misorientation makes from 2皍p in 23*. The interatomic interaction was opproximated by Morse' s pair semi-empirical potential. Two variants of relaxation technique were used: (1) rigid relax- ation with the change of atom quantity per a GB (vacancy relaxation ) and (2) full atomic relaxation by a molecular static method. The obtained orientation dependence has a good agreement with experi- ment. There are cusps on a curve in the range of special GB angles.The comparison of obtained curves with calculated ones in model Van der Merwe was carried out. Dependencies obtained in our investiga- tions are not smooth and have an oscillatory character. The oscillations reflect a discrete structure of a lattice.
