International Journal of Electrochemical Science
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2023
·Vol. 11
·期 12
·10135-10149
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IF 1.5
Lijuan Gong,Kangquan Qiao
The corrosion inhibition performances of Diantipyrylmethane (DAM) for mild steel in 0.5 M H 2 SO 4 were investigated using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscope (SEM) and quantum chemical calculation. The obtained results reveal that DAM acts as a mixed-type inhibitor with a predominantly anodic reaction, and the inhibition efficiency increases with increasing inhibitor concentration whereas decreases with increasing temperature. The adsorption of DAM on steel surface is found to obey Langmuir isotherm, and the adsorption mechanism is mixed physical and chemical adsorption. The results of quantum chemical calculation demonstrate that pyrazolone rings within molecular structure of DAM play a dominant role in corrosion inhibition of mild steel.
研究领域:
材料腐蚀与防护
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物理化学
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电化学
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表面科学
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量子化学
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DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 13
·期 2
·1985-2000
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IF 1.5
Zhe Zhang,Le Ruan,Weipeng Zhang,Yuzeng Lyu,Wei Shang,Yuqing Wen,Xiuying Li,Ling Wu,Yanni Jiao
The triazol-3-ylamine and three different kinds of Schiff base compounds are self-assembled on bronze surface. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements show that the triazol-3-ylamine and Schiff base self-assembled films can protect bronze from corrosion in 0.5 M HCl solution. The corrosion efficiency increases with the self-assembly time increasing and reaches a stable value after 8 h. The highest corrosion efficiency of the bronze electrode modified with self-assembled films reaches 95.81% after immersing in 0.005 M 2,4-Dibromo-6-[(4H-[1,2,4]Triazol-3-ylimino)-methyl]-phenol Schiff base solution for 10 h. X-ray photoelectron spectroscopy and scanning electrochemical microscope are used to characterize the inhibitive ability of the self-assembled films. Quantum chemical calculations and dynamic simulations indicate that the triazol-3-ylamine and Schiff bases molecules can absorb on the copper surface via chemisorption. The adsorption energy increases with the number of aromatic rings.
研究领域:
材料腐蚀与防护
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物理化学
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表面科学
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电化学
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计算化学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·Vol. 36
·期 10
·1726-1732
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IF 1.964
Huanhui Chen,Xiaoci Li,Guoqing Zhao,Hongbo Gu,Zhirong Zhu
The side-chain alkylation of toluene represents a novel, environmentally friendly, and low cost route for the production of styrene . However, the yield of styrene produced in this way is currently low, and the mechanism responsible for the side-chain alkylation of toluene is poorly understood. Furthermore, the reason for the higher catalytic efficiency of CsX over NaX and KX remains unclear. In this work, the free radical mechanism of the side-chain alkylation of toluene over basic zeolite X has been elucidated using quantum chemical calculations , together with isotope tracing experiments and the reaction between p -nitrotoluene and methanol. The adsorption isotherm of methanol showed that Cs + ions could block methanol from accessing the β-cage, which is where the side-chain alkylation reaction occurred. Furthermore, the H–D exchange results between toluene and deuterated toluene (C 6 D 5 CD 3 ) showed that CsX was more efficient as a catalyst than KX for the conversion of toluene to the corresponding benzyl radical (C 6 H 5 CH 2 • ). These two results therefore explain the higher catalytic activity of CsX towards side-chain alkylation than KX. Based on the free radical mechanism, the selectivity of styrene could be increased from 17.4% to 59.4% using CO 2 as carrier gas instead of N 2 .
研究领域:
物理化学
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催化化学
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材料化学
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反应机理
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理论化学
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能源化学
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环境化学
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2022
·
IF 3.841
Qi Wang,Shaopeng Fu,Xingyao Yang,Qinghao Sun,Junwei Zhang,Yichun Peng,Rongling Zhang,Zezhou Liang,Jianfeng Li
An organic nitrogen/oxygen-rich polymer (PFN-NDIN) was prepared via Suzuki reaction between 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-bis(3-N,N- dimethylaminopropyl)-9H-fluorene (FNB) and 4,9-dibromo-2,7-bis(3-(dimethyl-amino)propyl)naphthalenediimide (NDINBr 2 ) and utilized as a new inhibitor for HRB400 steels corrosion in alkaline medium of simulated concrete pore solution. The inhibition efficiency of this inhibitor was evaluated by electrochemical techniques. The electrochemical impedance spectroscopy (EIS) results showed that the protective capacity of PFN-NDIN on HRB400 steel increased with increasing concentration to attain 92.85% efficacy with 400 ppm at 288 K. Potentiodynamic polarization (PDP) plots indicated that PFN-NDIN is effective and acts as a hybrid inhibitor. The adsorption behavior of PFN-NDIN was fitted and found to follow the Langmuir isothermal adsorption line, with discussion of the relevant thermodynamic parameters. The effect of temperature on this inhibitor's the rust-inhibiting effect was investigated. The surface was then studied, showing that the interfacial corrosion of HRB400 steel was inhibited by PFN-NDIN molecules. The relationship between PFN-NDIN molecules’ structure and the inhibition efficiency was investigated by quantum chemical calculations. Several parameters were calculated, the findings revealed that the prepared materials correlated well with their electronic contribution capability.
研究领域:
材料腐蚀与防护
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高分子化学
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电化学
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建筑材料科学
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表面科学
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量子化学
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DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 36
·22485-22491
·
IF 3.108
Hailiang Zhao,Shanshan Tang,Qun Zhang,Lin Du
The weak intermolecular interaction between 2,2,2-trifluoroethanol (TFE) and 3-chloro-2-methyl-1-propene (CMP) has been investigated by gas phase FTIR spectroscopy and DFT calculations. CMP offers two hydrogen bond docking sites to the hydrogen bond donor: the chlorine atom (O–H⋯Cl) and the CC π electron system (O–H⋯π). DFT calculations suggest that MeOH approaches CMP in five different orientations. The structural, energetic, and spectroscopic parameters of the most stable structures in each orientation were studied, and their binding energies range from −25.5 to −19.5 kJ mol−1. The docking to the π system is at least 1 kJ mol−1 more favored than the docking to the chlorine atom. The equilibrium constant for complexation (2.3 × 10−2) was determined from the experimental and calculated intensity of the OH-stretching transition. The Gibbs free energy of formation was found to be 9.3 kJ mol−1. The nature of the non-covalent interaction was analyzed with the atoms in molecules (AIM) method.
研究领域:
物理化学
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结构化学
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分子光谱学
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量子化学计算
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分子间相互作用
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DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Xiaodong Wang,Lili Ye,Xiaoyuan Zhang,Zhihe Zhang,Jiuzhong Yang,Long Zhao
Acetaldehyde, ethylene oxide , and vinyl alcohol are three C 2 H 4 O isomers that are ubiquitous in combustion over a wide temperature range. A comprehensive reaction kinetics study has been performed for reactions that occur on the same C 2 H 4 O potential energy surface , mainly including the unimolecular reactions of three C 2 H 4 O isomers and the recombination reaction of CH 3 with HCO. Temperature- and pressure-dependent rate coefficients were updated or newly predicted by performing quantum chemical calculations coupled with RRKM/master equation simulations. The dominance of C C bond fission is reconfirmed for acetaldehyde decomposition at higher temperatures. The negligible contribution of CH 4 + CO channel from usual tight intramolecular H-shift transition state provides indirect evidence for previously reported roaming mechanism that was proposed to explain the observation of CH 4 + CO in acetaldehyde pyrolysis . For ethylene oxide pyrolysis , current experiment and kinetic prediction have a good consistency in branching ratios between the formation of acetaldehyde and vinyl alcohol products. The radicals of CH 3 + HCO can also be directly generated from ethylene oxide through a well-skipping reaction mechanism especially at higher temperatures. For CH 3 + HCO recombination, we highlight the importance of CH 3 CO + H channel that was often overlooked previously. Kinetic simulations show that the incorporation of updated rate coefficients and newly identified channels results in a measurable influence on C2 chemistry , indicating the possibility and necessity of further improvement of core mechanism in combustion kinetic models .
研究领域:
物理化学
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燃烧化学
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反应动力学
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量子化学计算
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分子反应机制
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DOI
高影响因子