FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Shuzhen Chen,Changlei Qin,Weiyang Yuan,Dawid P. Hanak,Jingyu Ran
Li 4 SiO 4 is acknowledged as a promising sorbent candidate in high-temperature CO 2 adsorption. However, reaction kinetics for the regeneration process of Li 4 SiO 4 , especially its dependence on CO 2 pressure is lack of understanding. This work designed and carried out a series of isothermal tests on the regeneration of pure Li 4 SiO 4 and K-Li 4 SiO 4 under CO 2 partial pressure of 0–0.5 atm and temperature of 625–725 °C. For the first time, the expression of ( P eq − P CO 2 ) n is introduced into the regeneration rate equation so as to reveal its dependence on CO 2 pressure. The reaction order ( n ) is found to grade according to the value of ( P eq − P CO 2 ), and the apparent activation energy is calculated as 284.42 kJ•mol −1 and 146.31 kJ•mol −1 for the regeneration of Li 4 SiO 4 and K-Li 4 SiO 4 , respectively. Furthermore, this work proposes that power law model with m = 4/3 is the most probable mechanism function for the regeneration of Li 4 SiO 4 -based sorbents.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Junjie Chen,Bo Jin,Guan Luo,Huihui Liu,Qingchun Zhang,Qi Huang,Rufang Peng
The thermodynamics and kinetics of the curing reactions between polyglycidyl nitrate (PGN) and toluene diisocyanate, isophorone diisocyanate, and polyaryl polymethylene isocyanate (PAPI) were studied by microcalorimetry. The reaction rate between PGN and PAPI was the fastest among the three reactions above. Three thermodynamics ( i.e. , activation enthalpy, entropy, and free energy), rate constant, and three thermokinetic parameters ( i.e. , activation energy, pre-exponential constant, and reaction order) of the curing reactions were obtained by calculating the results of the reaction between PGN and PAPI at a series of temperature from 303.15 K to 318.15 K. The linear relationship between ln k and the mole ratio of the isocyanate and hydroxyl groups was observed. The corresponding kinetic equation describing the curing reaction between PGN and PAPI was d α /d t = 10 −3.83 (1 − α ) 3.04 at 318.15 K.
研究领域:
高分子化学
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热力学
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反应动力学
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功能材料
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含能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Haoran Ma,Ping Li,Ailing Huang,Wei Zhao,Xuelan Zhang
Sulfonation of 1-tetradecene with liquid-phase sulfur trioxide generates simultaneously the alkene sulfonic acid and alkene sulfonate. The kinetics study is contributed to a deeper understanding of the sulfonation reaction and better controlling the process. The continuous microfluidic system was established to determine the kinetic parameters of 1-tetradecene sulfonation. A comprehensive kinetic model was developed, and the kinetic parameters were obtained. The activation energy is 14.7 ± 0.8 kJ mol −1 , with a pre-exponential factor of 118.4 ± 1.4. The reaction order for 1-tetradecene is second-order, and for sulfur trioxide, the reaction order is 0.3. By discretizing the reactor into microelements and conducting mass balance on each differential element method, integrating the obtained reaction kinetics model, calculating the required reaction time, and comparing it with experimental data within a reasonable range of error, the correctness of the derived reaction kinetics model has been verified.
研究领域:
化学工程
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物理化学
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微流控技术
✓ 已验证
产品关联
DOI
高影响因子
Science Bulletin
·
2025
·
IF 21.1
Yuqing Luo,Binbin Pan,Xiaohan Yu,Xue Ding,Xinmin Shi,Yanguang Li
The electrochemical reduction of CO 2 to formic acid or formate represents one of the most economically promising route for CO 2 utilization. While substantial advances in catalyst design and electrolyzer engineering have been achieved in recent years, critical uncertainties remain regarding the reaction pathway and the often-debated role of alkali metal cations. Resolving these discrepancies requires precise kinetic analysis under well-defined conditions. In this work, we systematically investigate the kinetics of CO 2 reduction to formic acid or formate across a wide pH range, enabled by two key developments: the identification of BiPO 4 as a stable precatalyst under acidic conditions through comprehensive screening, and the implementation of sensitive ion chromatography for accurate product quantification, even at low current density where conventional methods struggle. Our electrokinetic data suggest that the reaction proceeds via sequential electron and proton transfers rather than proton-coupled electron transfer as proposed by many computational simulations. Notably, the rate-determining step transitions from the proton transfer step at low overpotential to the first electron transfer step at high overpotential, with the proton source dependent on electrolyte pH. Furthermore, through K + reaction order analysis and crown ether chelation experiments, we demonstrate that the alkali cations are not merely spectators but actively participate in the reaction, likely by stabilizing negatively charged intermediates via electrostatic interactions.
研究领域:
电化学
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催化
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可持续能源
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二氧化碳利用
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反应动力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2023
·Vol. 13
·期 21
·6185-6197
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IF 5
Hui Guo,Tingting Ge,Yuchao Li,Yuxia Li,Yanxia Zheng,Xinpeng Guo,Haofei Huang,Ming Wang,Cuncun Zuo
Organic solvent method was used to prepare the active component VPO, which was loaded on ball-milled γ-Al2O3 support. VPO/γ-Al2O3 catalysts were synthesized by in situ generation for the synthesis of acrylic acid (AA) by the aldol condensation of acetic acid (HAc) and formaldehyde (HCHO). The effects of the calcination temperature and the loading of the active component VPO on catalytic activity were systematically investigated. XRD, BET, SEM, CO2/NH3-TPD, FT-IR spectroscopy, and TG techniques were used to characterize the VPO/γ-Al2O3 catalysts. The results showed that the catalyst had the best crystal structure and acid–base activity center at a calcination temperature of 350 °C. The catalytic performance was evaluated using a fixed bed reactor. 60% VPO/γ-Al2O3 exhibited the highest reactivity, and the yield of AA was up to 51.5%. Response surface methodology (RAM) was used to optimize the reaction conditions for aldol condensation. The kinetic equation and reaction order of the aldol condensation reaction were determined using the VPO/γ-Al2O3 catalyst. It provides guidance for the in-depth study of aldol condensation reactions in the future.
研究领域:
催化
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化学工程
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材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2025
·
IF 8.1
Xinyao Wang,Zhiling Huang,Yue Meng,Bo Xie,Zheming Ni,Shengjie Xia
In this paper, ZnCdS/ZnCr-LDHs Z-scheme heterojunction containing zinc-oxygen bi-vacancy (V Zn + O ) were constructed and applied to photodegradation of norfloxacin (NOR) in water. A comprehensive investigation was conducted into the effects of concentration of V Zn in the composite, amount of catalyst, concentration of norfloxacin, temperature of the solution, and pH on the degradation activity. It comprehensively investigates the reaction kinetics, establishing a complete kinetic equation and determining the activation energy. Key parameters including catalyst dosage, pH, and reaction orders are systematically analyzed to elucidate their influence on the reaction process. The reaction mechanism of photodegradation of NOR is deeply analyzed from the perspectives of thermodynamics and kinetics. Z-scheme heterojunction not only facilitates the separation of photogenerated charges, but also preserves photogenerated electrons with strong reducing ability and photogenerated holes with high oxidizing ability; The existence of double vacancies not only provides more active sites for the material, but also regulates the band structure of the material, which contributes to the generation of free radicals. The synergistic effect of Z-scheme heterojunction and V Zn + O resulted in a removal rate of 89 % for NOR with a concentration of 20 mg/L after 90 min of visible light irradiation. In addition, based on ESR and XPS test results as well as DFT calculations, the synergistic mechanism of Z-scheme heterojunction and V Zn + O in the photodegradation process was analyzed in detail from the aspects of band structure, electron transfer, free radical species, and built-in electric field. The pathway of NOR photodegradation and the toxicity analysis of intermediate products were also provided.
研究领域:
环境科学
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材料科学
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化学工程
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光化学
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水处理技术
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）