COMBUSTION AND FLAME
·
2024
·
IF 5.8
Hong Wang,Bingzhi Liu,Qiang Xu,Shijun Dong,Zhandong Wang,Long Zhu
Cyclopentanone (CPN) is a widely available biofuel with excellent combustion properties, but detailed speciation profiles during its pyrolysis have rarely been studied. This work examines the pyrolysis of CPN in a jet-stirred reactor (JSR) at atmospheric pressure, with residence time of 2 s and a temperature range from 830 K to 1100 K. Dozens of pyrolysis intermediates and products were measured using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) and gas chromatography (GC). Among them, several new species were observed, including water, carbon dioxide , formaldehyde, indene , 1,2-dihydroindene, naphthalene , 1,2-dihydronaphthalene, 1-methylnaphthalene, acenaphthylene , biphenyl , and fluorene . A detailed kinetic model was developed based on the literature, and in general, it predicted the experimental results for most species well. Kinetic analyses indicated that the consumption of CPN was controlled by the bimolecular reactions with H atom. The formation of water, carbon dioxide and formaldehyde could be explained by the reaction pathways of OH radical. The pyrolysis of CPN yielded a significant number of alkenes and alkynes at higher temperatures; the bimolecular addition reactions of these species with resonantly stabilized radicals are important to the formation of polycyclic aromatic hydrocarbons (PAHs). Based on those, this work provides valuable insights into CPN pyrolysis chemistry and it promotes the development of a comprehensive CPN combustion model.
研究领域:
燃烧化学
·
能源化学
·
反应动力学
·
分析化学
·
环境化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 15
·21459-21465
·
IF 4.527
Xianwei Su,Xiaojia Shang,Yusi Che,Shaolong Li,Jianxun Song,Jilin He
Homogenous ZrC x O y powders have been successfully synthesized by in-situ electro-reduction of solid ZrO 2 –C composite precursors in molten CaCl 2 . The effect of applied cell voltage and molar ratio of ZrO 2 to C on preparation of ZrC x O y were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO 2 is firstly converted to CaZrO 3 . The resulting CaZrO 3 is then reduced to ZrC x O y . The ZrC x O y formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO 2 to C: a higher cell voltage and lower molar ratio of the ZrO 2 to C are more preferable for the formation of ZrC x O y powder. Homogenous ZrC x O y powders with particle size of ~100 nm are synthesized by ZrO 2 /C starting elemental powders in CaCl 2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO 2 to carbon starting materials is 1:1.0.
研究领域:
材料科学
·
无机非金属材料
·
电化学合成
·
粉末冶金
·
固态化学
✓ 已验证
DOI
高影响因子
EES Catalysis
·
2023
·Vol. 1
·期 3
·312-321
·
IF 0
Yiqiao Wang,Siyuan Pan,Huan Li,Dewang Li,Yong Guo,Sijia Chi,Chuannan Geng,Shichao Wu,Quan-Hong Yang
Despite lithium–air batteries having unprecedented theoretical energy supremacy, rambling Li2O2 growth typically impedes O2 diffusion and electron transfer, causing low capacity, poor charging kinetics and short cycle life. Herein, we propose synergistic catalysis in the cathode by engineering the crystal facet of Fe2O3 nanoplates and introducing a visible light-excited photochemical effect. The growth of Li2O2 is regulated with a uniform distribution, mitigating local product aggregation and thus reducing the barriers of O2 diffusion and electron transfer. The improved reaction kinetics lead to ∼420% capacity improvement, low charge potential, superior rate performance, and long-term stability (300 cycles) in actual air. We reveal a mechanism that photoelectrons around each catalyst node and the resultant homogeneous internal electric field increase charge transfer, decrease soluble intermediates, and enable high electrochemical reversibility of amorphous Li2O2 with an ordered process. This study provides inspiring insights for future research into controlling product ordering in Li–air batteries.
研究领域:
电化学
·
纳米材料科学
·
能源化学
·
催化化学
·
电池技术
✓ 已验证
DOI
CHINESE JOURNAL OF CHEMISTRY
·
2011
·Vol. 29
·期 9
·1906-1910
·
IF 0.773
Lin Yan,Wenguo Yang,Lixin Li,Yang Shen,Zhiyong Jiang
A mild and facile Wittig reaction between N -substituted maleimides and aldehydes has been developed. Various synthetically valuable alkylidenesuccinimides were obtained from this one-pot reaction in high yields (up to 99%). The product was obtained by simple filtration and no extra purification was necessary. Ethanol, an environment-benign solvent, was found to be a suitable reaction medium.
研究领域:
有机化学
·
药物化学
·
绿色化学
·
合成方法学
·
medicinal chemistry
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Xiaozhen Chen,Ji Qi,Pan Wang,Chuang Li,Xiao Chen,Changhai Liang
Herein, PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness are synthesized via a polyvinyl alcohol (PVA) involved approach and used for hydrogen evolution reaction (HER). The average crystallite size of the PVA protected nMo 2 CN nanospheres (6.1 nm) is one third of that of the PVA-Mo 2 C/Mo 2 N without PVA protection (17.9 nm). At 10 mA cm −2 current density, the as-synthesized PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness exhibit HER overpotentials of 132 mV and 142 mV with corresponding Tafel slope of 51.8 mV dec −1 and 50.4 mV dec −1 in acid and alkaline medium, respectively. This high apparent activity can be attributed to the high intrinsic activity originated from the adjacent surface active sites of Mo 2 C and Mo 2 N as well as the large ECSA of PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Meng Wan,Han Zhu,SongGe Zhang,HaoNan Jin,YanKun Wen,LiNa Wang,Ming Zhang,MingLiang Du
Oxygen evolution reaction (OER) plays an important role in various renewable energy systems . Owing to its complex four-electron redox process , the OER process with sluggish kinetics often requires electrocatalysts to reduce the overpotential and promote the reaction rate. Herein, we have proposed an “all-in-one” strategy to synthesize mutil-elemental perovskite oxides nanofibers (NFs) with hollow and porous structures by using electrospinning technology and Ostwald ripening approach. The hollow La 0.7 Sr 0.3 Co 0.25 Mn 0.75 O 3 nanofibers (LSCM NFs) consist of large amounts of building block La 0.7 Sr 0.3 Co 0.25 Mn 0.75 O 3 nanoparticles (LSCM NPs), forming the unique architecture and the morphologies can be engineering by adjusting the calcination temperatures and the heating rates . Notably, the hollow LSCM NFs prepared at 800 °C and 10 °C min −1 demonstrated the excellent electrocatalytic performance, with overpotential of 340 mV at current density of 10 mA cm −2 and Tafel slope of 111 mV dec −1 , as well as the long-term stability in alkaline electrolyte . The hollow NFs architectures exhibited a large specific surface area , a high porosity and a large inner space, which are beneficial for the OER, reducing the overpotentials and accelerating the electrode kinetics .
研究领域:
材料化学
·
电化学
·
纳米材料科学
·
能源催化
·
功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2013
·Vol. 34
·期 12
·2161-2166
·
IF 1.304
Mingming Zhang,Manman Jiang,Changhai Liang
A basic anion exchange resin , Amberlite IRA-900, was loaded with Pd(C 3 H 5 )(C 5 H 5 ) by an easy metal-organic chemical vapor deposition (MOCVD) approach to give Pd@IRA-900 catalyst after reduction at room temperature . Ultraviolet-Visible spectroscopy results showed a red shift of the absorption peak of Pd 2+ after the Pd precursor was loaded on the resin, indicating that a chemical reaction occurred between the precursor and the support. Pd nanoparticles with 2.6 nm of average size were well dispersed on the support. The Pd@IRA-900 catalyst showed high activity for different kinds of aryl halides in Suzuki-Miyaura coupling reactions under mild and aerobic conditions. Excellent recyclability of Pd@IRA-900 catalyst was also observed in the Suzuki-Miyaura coupling reaction of iodobenzene and phenylboronic acid . A bifunctional catalyst Pd@IRA-900(OH) was synthesized by pretreating the ion exchange resin support with NaOH before Pd loading, which successfully catalyzed the Suzuki-Miyaura reaction of iodobenzene and phenylboronic acid without base under aerobic conditions.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
纳米催化
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 44
·17502-17510
·
IF 3.069
Jie Ren,Zhenguo Wang,Yu Feng,Bangjun Guo,Ke Yu,Ziqiang Zhu
In this work, we report the first-principles investigation and synthesis method for a hollow-MoS2/C heterostructure applied to a hydrogen evolution catalytic material. First principles investigation was used to calculate the free energy of hydrogen ion adsorption at the heterostructure interface at different surface adsorption ratios. The change of the density of states before and after carbon coating proved that carbon coating improves the conductivity of the catalyst. Higher reactivity areas and higher conductivity can significantly improve hydrogen evolution catalytic performance, which is also demonstrated by electrochemical testing. Hollow-MoS2/C exhibits a low onset overpotential of 96 mV and a low Tafel slope of 67.4 mV dec−1, as well as good catalytic stability. The composite catalyst prepared by a two-step method has a larger specific surface area and a larger porosity, can significantly suppress the collapse and stacking effect caused by the electrode circulation process, and improve the cyclic reversibility and stability of the material. This work is expected to provide a meaningful reference for solving the problem of cycling performance degradation of non-precious metal-catalyzed hydrogen evolution materials.
研究领域:
材料化学
·
电化学
·
纳米材料科学
·
催化化学
·
能源材料
·
理论计算化学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2014
·Vol. 16
·期 37
·8910-8916
·
IF 3.858
Feng Ye,Hui Liu,Wenlai Huang,Jun Yang
Controlling the morphology of noble metal nanoparticles can be an effective way to produce nanomaterials with favourable properties. Herein, we report our study on the effects of diffusion rate and reaction kinetics on the morphology of a number of noble metal (Au, Ag, Pd, and Pt) nanoparticles. A glass reactor based on electrochemical reduction or photo-reduction has been designed to achieve control of diffusion and chemical reduction of the different noble metal precursors. The results show that the noble metal nanoparticles with flower-like, core–shell, or wheel-like morphologies could be obtained at a relatively high diffusion rate due to the presence of additional growth of metal precursors on the preformed metal nuclei, while at relatively low diffusion, the as-prepared noble metal nanoparticles are small and quasi-spherical due to the relatively fast reduction of metal precursors. The experimental observations are also confirmed qualitatively by kinetic Monte Carlo (kMC) simulations. Since diffusion and reaction kinetics are universal and key factors in the synthesis of nanomaterials, the findings in this work might provide an effective way to manipulate the morphology of nanomaterials for a given application.
研究领域:
纳米材料科学
·
物理化学
·
材料合成
·
胶体与界面化学
·
计算材料学
✓ 已验证
DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 6
·期 5
·e12415
·
IF 13.443
Lin Chen,Jingwen Zhou,Junxiang Zhang,Guicai Qi,Bin Wang,Jianli Cheng
High energy density Li-CO 2 batteries have attracted much attention owing to the “two birds with one stone” feature in fixing greenhouse gas CO 2 and providing renewable energy. However, poor reversibility of the discharge product Li 2 CO 3 is one of the main problems that limit its application, resulting in poor cycling stability and severe polarization. Herein, copper indium sulfide (CIS), a semiconducting non-precious metal sulfide, is fabricated as cathode catalysts for high-performance Li-CO 2 batteries. Combined with the synergistic effect of bimetallic valence bonding and coordinated electron transfer, Li-CO 2 batteries using CIS cathodes exhibit high full specific discharge capacity, excellent rate capability and cycle stability, namely it delivers a high specific full discharge capacity of 8878 μAh cm −2 , runs steadily from 10 to 100 μA cm −2 , and performs a stable long-term cycling behavior (>1050 h) under a high energy efficiency of 84% and a low charge voltage of approximately 3.4 V at 20 μA cm −2 within 100 μAh cm −2 . In addition, a flexible Li-CO 2 pouch cell is constructed to reveal the potential of employing CIS to fabricate flexible high energy storage devices in practical applications. This work shows a promising development pathway toward next-generation sustainable energy storage devices.
研究领域:
电化学
·
能源材料
·
纳米催化
·
可持续能源存储
·
金属-气体电池
✓ 已验证
DOI
高影响因子
Energy & Environmental Materials
·
2022
·Vol. 6
·期 3
·e12351
·
IF 13.443
Qiyu Wang,Xiangqun Xu,Bo Hong,Maohui Bai,Jie Li,Zhian Zhang,Yanqing Lai
Quasi-solid-state lithium metal battery is a promising candidate for next generation high energy density and high safety power supply. Despite intensive efforts on electrolytes, uncontrolled interfacial reactions on lithium with electrolyte and patchy interfacial contacts still hinder its practical process. Herein, we bring in rationally designed F contained groups into polymer skeleton via in-situ gelation for the first time to establish quasi-solid-state battery. This method achieves a capacity retention of 90% after 1000 cycles at 0.5C with LiFePO 4 cathodes. The interface constructed by polymer skeleton and reaction with –CF 3 lead to the predicted solid electrolyte interface species with high stability. Furthermore, we optimize molecular reactivity and interface stability with regulating F contained end groups in the polymer. Comparisons on different structures reveal that high performance solid stable lithium metal batteries rely on chemical modification as well as stable polymer skeleton, which is more critical to construct robust and steady SEI with uniform lithium deposition. New approach with functional groups regulation proposes a more stable cycling process with a capacity retention of 94.2% at 0.5C and 87.6% at 1C after 1000 cycles with LiFePO 4 cathodes, providing new insights for the practical development of quasi-solid-state lithium metal battery.
研究领域:
电化学
·
材料科学
·
能源存储
·
界面化学
·
高分子化学
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 6
·期 3
·1801663
·
IF 4.834
Wentian Huang,Qingwei Zhou,Shaoqiang Su,Jing Li,Xubin Lu,Xingsen Gao,Xin Wang,Mingliang Jin,Guofu Zhou,Zhang Zhang,Junming Liu
Loading 2D layered transition metal dichalcogenides (TMDs) on p-type silicon photocathode is suitable for hydrogen production in solar-driven photoelectrochemical (PEC) water splitting. Similarly, various nanostructured TMDs exposing more active sites are widely explored for improving the PEC performances of composite photoelectrodes. Here, defect engineering using a controllable argon ion beam bombardment is presented on ReS 2 /Si photocathode. The atomic vacancy defects are introduced on the 2D ReS 2 to realize high-density active sites, which significantly enhance the solar-driven hydrogen evolution reaction performance of ReS 2 /Si photocathode. The highest photocurrent density of 18.5 mA cm −2 (at 0 V vs reversible hydrogen electrode) is achieved, under a simulated sun irradiation.
研究领域:
材料科学
·
光催化
·
能源化学
·
半导体器件
·
纳米科技
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）