CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2023
·Vol. 39
·期 6
·1064-1069
·
IF 3.1
He Huan,Zou Zhengxi,Hua Weiming,Yue Yinghong,Gao Zi
A series of ZnO-modified cobaltous ion exchanged ZSM-5 catalysts is prepared using incipient wetness impregnation and characterized by X-ray diffraction (XRD), N 2 adsorption, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DR UV-Vis), X-ray photoelectron spectroscopy (XPS), pyridine-adsorbed Fourier transform infrared (Py-IR) and Raman. Their catalytic performance towards CO 2 -assisted dehydrogenation of ethane to ethylene has been evaluated. The addition of ZnO onto CoZSM-5 obviously improved the yield of ethylene as well as the conversion of CO 2 . The promoting effect is attributed to the good activity of ZnO for the reverse water gas shift (RWGS) reaction, which enhances the coupling between RWGS and ethane dehydrogenation.
研究领域:
催化化学
·
化学反应工程
·
材料科学
·
环境化学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2020
·
IF 3.795
Shaoqi Zhou,Xuexia Wang,Xiangning Bu,Huaizhi Shao,Yue Hu,Muidh Alheshibri,Biao Li,Chao Ni,Yaoli Peng,Guangyuan Xie
In this study, kerosene emulsions with different average droplet sizes (700 nm, 854 nm, and 996 μm) were prepared to investigate their effects on the entrainment of gangue materials and the selectivity index in the flotation of aphanitic graphite. The calculation results based on Neethling and Cillers’s model indicate that a decrease in the average droplet size of emulsified kerosene would result in a decrease in the entrainment of gangue materials, which corresponds to the observations of froth layer height, maximum water recovery rate, and bubble size in the top section of the froth zone. This may be ascribed to the enhanced collision probability between graphite particles and oil droplets, as well as the increased modified flotation rate constant compared to the micro-scale droplets. It is also noted that the selectivity index in graphite flotation increases as the average droplet size of kerosene emulsions decreases. This is largely due to the synthetic effect of the mitigated gangue entrainment and the intensified collision between graphite particles and oil droplets in the presence of nano-scale oil droplets.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Xiaojun He,Xiaojing Li,Hao Ma,Jiufeng Han,Hao Zhang,Chang Yu,Nan Xiao,Jieshan Qiu
3D interconnected graphene nanocapsules (GNCs) were prepared from diverse aromatic hydrocarbons by a nano-ZnO-template strategy coupled with in-situ KOH activation technique. The as-made graphene networks feature thin carbonaceous shells with well-balanced micropores and mesopores. Such 3D porous networks provide freeways for good electron conduction , short pores for ion fast transport, and abundant micropores for ion adsorption. As the electrodes in supercapacitors , the unique 3D GNCs show a high capacitance of 277 F g −1 at 0.05 A g −1 , a good rate performance of 194 F g −1 at 20 A g −1 , and an excellent cycle stability with over 97.4% capacitance retention after 15000 cycles in 6 M KOH electrolyte. This synthesis strategy paves a universal way for mass production of 3D graphene materials from diverse aromatic hydrocarbon sources including coal tar pitch and petroleum pitch for high performance supercapacitors as well as support and sorbent .
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
Mining Metallurgy & Exploration
·
2024
·Vol. 41
·期 2
·1051-1067
·
IF 1.5
Wang Shiwei,Wei Guomin,Kong Rongjie
Owing to the selective oxidation and uneven combustion that occur on the surface of carbon anode, some carbon particles detach and form carbon residue, which is defined as spent anode slag (SAS). The highly graphitized and toxic impurities such as fluorite (CaF 2 ), corundum (α-Al 2 O 3 ), and cryolite (NaAl 11 O 17 ) are crucial components of SAS resource but are difficult to separate from graphite. This study developed a method of using water-soluble (emulsified) kerosene to separate the carbon particles from the toxic impurities in the SAS resource. The flotation purification approach of utilizing conventional kerosene was experimentally investigated and compared with that of using water-soluble kerosene. The results showed that with the use of emulsified kerosene, the maximum combustible matter recovery of the carbon particles was 89.86% while that of using traditional kerosene was 80.30%. The emulsified kerosene was comprehensively examined by various instruments to clarify its adsorption mechanism on the carbon particle surfaces. Because of the superior dispersibility of emulsified kerosene, it effectively envelops carbon particles with a smooth surface, oxygen-containing functional groups, and hydrophilic C–F bonds, thereby increasing the surface hydrophobicity and flotation responses of targeted carbon particles.
研究领域:
冶金学
·
环境科学
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2021
·
IF 6.186
Dongjing Liu,Lingtao Yang,Bin Li,Jiang Wu
Rice husk , as an abundant agricultural waste and renewable biomass, is adopted to produce porous silica which is used as a potential carbon-free adsorbent for mercury emission control of coal-fired power plants. The rice husk derived porous silica (RHS) exhibits a good Hg 0 adsorption capability with Hg 0 removal efficiency above 80% in the temperature range of 60–140 °C, which is plausibly due to the big specific surface area and mesoporous structure. The mercury removal performance of RHS can be evidently reinforced by KBr modification. The optimal KBr loading value and reaction temperature are 2 wt% and 140 °C, respectively. Acidic gas components, such as NO and SO 2 , both show slight inhibitive effects on Hg 0 adsorption process probably owing to the competitive adsorption or the elimination of adsorption sites.
研究领域:
环境科学
·
大气污染控制
·
材料科学
·
吸附技术
·
能源工程
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Jian Qiao,Xiang-Ming Hu,Yun-Tao Liang,Qian Zhang,Wei Wang,Yan-Yun Zhao,Shuang Ju,Fu-Chao Tian
In order to improve the stability time and foaming ratio of gel foam, and change the traditional preparation method of gel foam. In this paper, using super-hydrophobic nanoparticles , PVA, sodium tetraborate and sodium bicarbonate as the main raw materials, based on the self-assembly effect of super-hydrophobic nanoparticles and hydrophilic macromolecules, a high-foaming gel foam (PGF) without foaming agent was prepared. Through the test, the foaming volume of the 100 ml PGF can reach 329 ml without adding foaming agent, which is 1.4 times of the traditional gel foam (TGF) and 1.2 times of the viscous foam (VF). Even without foaming agent, the PGF has a half-life of more than 13 days and can retain water for more than 15 h at 100 °C. Response surface analysis showed that the foaming performance of the PGF was affected by nanoparticles, sodium tetraborate and sodium bicarbonate, among which the content of nanoparticles was the main factor. At the same time, sodium tetraborate and sodium bicarbonate also significantly affect the water retention performance of PGF. Fire prevention experiments show that the gel foam prepared by this method also has excellent fire prevention ability, which can effectively inhibit the consumption of hydroxyl group and the generation of methyl and methylene group in the process of coal oxidation. Moreover, it can still play an inhibiting ability at a high temperature of 400 °C, and can effectively prevent the recurrence of coal fire after extinguishing. The development of PGF provides a new method for the preparation of gel foam in the future. At the same time, the application of foaming agent is avoided, which reduces the pollution of surfactant to the environment.
研究领域:
材料科学
·
消防工程
·
能源安全
·
高分子化学
·
界面科学
✓ 已验证
DOI
高影响因子
EES Catalysis
·
2023
·Vol. 2
·期 1
·365-378
·
IF 0
Yaqi Hu,Zhong Liang,Yabin Zhang,Yaping Du,Hongbo Zhang
Hydrogen production with high efficiency and low CO selectivity in methanol steam reforming (MSR) is of pivotal importance. However, there is limited understanding of the active sites and reaction mechanisms during catalysis. In this study, we maximized the interfacial site, known as the active component in MSR, of Ni–CeOx by atomically dispersed Ni and Ce over the carbon–nitrogen support to generate the Ni and Ce dual-atomic catalyst (DAC), which achieved 6.5 μmolH2 gcat.−1 s−1 H2 generation rate and 0.8% CO selectivity at 99.1% methanol conversion at 513 K. The finely dispersed Ni and Ce structure was confirmed by systematic characterization of AC HAADF-STEM and EXAFS. Electron transfer from Ce to Ni was confirmed simultaneously by quasi-in situ XPS analysis. Moreover, the reaction mechanism of methanol steam reforming was clarified by combining kinetic studies with isotope-tracing/exchange analysis (i.e., KIEs and steady-state isotopic transient kinetic analysis (SSITKA)), which suggests that the steam reforming consists of two tandem reaction processes: methanol decomposition (MD) and water–gas shift (WGS) reaction, with methanol and water activation at independent active sites (e.g., Ni and oxygen vacancy over CeOx), and that hydrogen generation was primarily determined by both C–H bond rupture and OL–H (OL represents the lattice oxygen) cleavage within methoxy and hydroxyl groups, respectively, with the catalytic surface mainly covered by CO and methoxy groups. A shift of WGS involvement in hydrogen generation from negligibly influenced to significantly promoted was selectively observed once modifying the reaction from differential conditions to a high methanol conversion regime, and two quantification methods have been established by comparing the molecule ratio between CO and CO2 or H2.
研究领域:
催化化学
·
能源科学
·
材料科学
·
表面化学
✓ 已验证
DOI
Open Ceramics
·
2024
·
IF 2.9
Rui Gao,Zhangjian Zhou,Jing Yang,Jinquan Zhang
The relationship between the intrinsic properties of seven different types of fly ash and the compressive strength of the resulting geopolymers was investigated. A comprehensive examination of the effect of chemical and mineralogical compositions, particle size distribution, on the compressive strength of the fly ash-based geopolymers were performed. Results revealed that particle size distribution had a more significant impact on reaction activity than amorphous phase content or average particle size alone. Therefore, a novel concept of 'reaction volume' based on the geopolymerization reaction mechanism was proposed, which reveals a high correlation between the reactivity of fly ash and the compressive strength of geopolymers, thereby enhancing the predictability of the process. The degree of reactivity, formulated through the integration of reaction volume and amorphous silica-aluminum content, was identified as a robust predictor of compressive strength, which can serve as a crucial tool for evaluating fly ash for the production of alkali-activated materials.
研究领域:
材料科学
·
土木工程
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Wen-ying Li,Wei Wang,Hai Mu,Wang Li,Cui-ping Ye,Jie Feng
To realize the fast and accurate determination of coal-based crude oils, gas chromatography combined with mass spectrometry and flame ionization detection is employed to assist in qualitative and quantitative analysis. In addition, material balance is introduced into the analysis at the same time as a constraint. A new equation is deduced and verified, which can predict flame ionization detection relative response factors mainly by the molecular formula of the compounds. Meanwhile, the formula is integrated with the area normalization method. The standard compound addition method is employed to test the reliability as well, and the recovery experiments show that the designed system is simple, fast, accurate and effective. Finally, the analytical method system is applied to characterize the light weight fractions of coal-based crude oil, and the results show that approximately 70–80 wt% of the components can be balanced.
研究领域:
能源化学
·
分析化学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Shoutao Ma,Qiang Yu,Yafei Hou,Jinfang Li,Yuan Li,Zhanhua Ma,Lanyi Sun
Coal tar is a byproduct of low temperature coal carbonization. The separation of the compounds has great significance since its main component is the mixture of phenols and hydrocarbons. In this paper, the separation of specific phenolic compounds from model coal tar (phenols + hexane) was studied. The solvent was screened by empirical analysis, the universal quasichemical functional group activity coefficient (UNIFAC), and conductor-like screening model COSMO-SAC (segment activity coefficient). COSMO-SAC was used to calculate the capacity, selectivity, and performance index of solvents. Finally, the monoethanolamine (MEA) was selected as the solvent to extract the phenols. The liquid–liquid equilibrium for the ternary mixture of phenols + hexane + MEA was measured at 303.15 K and 323.15 K under atmospheric pressure, and the results showed that MEA provided a high distribution coefficient, efficiency, and selectivity for phenols. Meanwhile, the extraction process of phenols was simulated based on the nonrandom two-liquid (NRTL) model, for which binary interaction parameters were obtained through calculations of phase equilibrium. The results showed that the purity of phenols can achieve more than 99.5 wt % using MEA as a solvent.
研究领域:
化学工程
·
分离科学
·
热力学
·
燃料化学
·
环境化工
✓ 已验证
DOI
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2016
·
IF 3.48
Zuhua Zhang,John L. Provis,Jin Zou,Andrew Reid,Hao Wang
Variations between fly ashes can lead to significant differences in the geopolymers derived from them, in both microstructural and mechanical properties. This study assesses the effect of physical, crystallographic and chemical characteristics of fly ash on geopolymerisation performance and the strength of the resulting binders. Physical and glass chemistry factors are combined to develop a comprehensive index to evaluate the suitability of fly ashes for the production of high-strength geopolymers. An equation for this index is proposed, developed using five typical low-calcium fly ashes and then validated against a further eight literature datasets, showing a good relationship between the ranking order of the calculated index and the compressive strengths of geopolymer pastes produced with comparable activator and paste workability. This index can be used to screen the source materials, which is of significant value in moving alkali activated cements towards acceptance in practice.
研究领域:
材料科学
·
硅酸盐化学
·
建筑材料
·
固废资源化
·
胶凝材料化学
✓ 已验证
DOI
高影响因子
FUEL
·
2014
·
IF 3.406
Wenqing Li,Liying Wang,Yu Qiao,Jian-Ying Lin,Meijun Wang,Liping Chang
Understanding the effect of the atmosphere on the release of alkali and alkaline-earth metals (AAEM) during oxy-fuel combustion is important for the development of oxy-fuel combustion technologies with reduced problems with particulate formation and corrosion. To this end, we examined the release behavior of AAEM during oxy-fuel combustion in different gas environments. A drop-tube reactor and ion chromatography were used to investigate the release rates of AAEM. Our results show that the release rates of Na and K were higher than those of Ca and Mg in all types of gas environments. Experimental conditions that favor combustion, namely, higher temperature, higher oxygen content, and longer residence time, markedly increased the release rates of Na and K, whereas changes in the release rates of Ca and Mg were much smaller. The presence of SO 2 in the atmosphere suppressed the release of AAEM via formation of sulfates, whereas the presence of H 2 O promoted it. A synergistic effect of H 2 O and SO 2 on the release of AAEM during oxy-fuel combustion was observed.
研究领域:
燃烧化学
·
能源工程
·
环境化学
·
材料腐蚀
·
颗粒物形成
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）