CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Huihui Deng,Baozhen Li,Wenchun Zheng,Qin Sun,Mengjia Zhu,Jun Zuo,Yu Tang,Lizhi Wu,Li Tan
Propane dehydrogenation is one of the most promising routes for propylene production due to its single reactant, product and high economic efficiency. For Co-based catalysts, the state of Co species is one of the important factors affecting the performance of propane dehydrogenation. Here, we designed zeolite Silicalite-1 (S-1) with different silanol nests content as support to investigate the effect of silanol nests content to form Td-Co(II) species. It is found that the content of silanol nests in the S-1 supports have a linear correlation with the formation of T d -Co(II) species and corresponding PDH catalytic activity through the study of the catalyst structure-performance relationship. And the silanol nests of S-1 could be fully coordinated with 0.5 wt% Co content over 0.5Co/S-1-1-HTS in the form of T d -Co(II) species to maximize the Co atomic utilization. Correspondingly, 0.5Co/S-1-1-HTS shows the most excellent catalytic activity and stability, with C 3 H 6 generation rate of 3014 mmol C 3 H 6 g Co −1 h −1 and deactivation rate of 0.07 h −1 at 550 °C.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Zhikang Xu,Yunxing Zhang,Xing Wu,Haibo Zhu
Co-based catalysts are emerging as one of the most promising catalysts for propane dehydrogenation (PDH) due to their abundant availability, environmental friendliness, and efficient activation of the C–H bond. Isolated Co(II) is recognized as the active site for activating the C–H bond in PDH; however, the controllable synthesis of Co catalysts with well-defined isolated Co(II) remains a challenge. In this study, a direct and straightforward route was developed for the synthesis of Co-Beta using a fluorine-assisted hydrothermal crystallization method. The structure of Co-Beta was studied using various characterization tools, including XRD, STEM, H 2 -TPR, UV–vis, XPS, solid-state 29 Si MAS NMR and EXAFS techniques. It was confirmed that the Co species are incorporated into the structure of Beta zeolite, existing as isolated Co(II) sites embedded within the framework of Beta zeolite. The optimized catalyst, 1.0Co-Beta, exhibits excellent performance in PDH, achieving a propane conversion of approximately 50 % and propylene selectivity of around 96 % at 600 °C. This performance surpasses that of previously reported non-noble metal catalysts. This study provides fundamental insights on the design and synthesis of highly dispersed metal oxide catalysts for PDH.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
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IF 7.2
Fangfang Li,Xiaofang Hou,Wei Fu,Jinjin Wang,Ying-Hua Zhou
The efficient transformation of CO 2 into high-value chemicals remains a significant challenge, particularly in the design of heterocatalysts capable of simultaneous multi-site activation towards the substrate. In this work, we develop the novel Zr-MOF catalysts incorporating both cobalt(II) meso-tetra(4-carboxyphenyl)porphine (CoTCPP) complex and the imidazolium bromide-based ionic liquid (IL) containing different alkyl chain (RImBr), where R = Et, Pr, Bu, and Pe), denoted as CoTCPP-UiO-66-IL(RImBr). The catalysts were synthesized through a solvothermal method followed by a post-synthetic modification. Among the prepared catalysts, CoTCPP-UiO-66-IL(BuImBr) demonstrated exceptional performance on the solventless and cocatalyst-free conversion of epichlorohydrin into chloropropene carbonate, achieving a remarkable 99% yield under mild conditions (90 °C and 1.0 bar CO 2 ). This outstanding catalytic efficiency was attributed to the synergistic effects of the dual Lewis-acid active sites offered by Zr-MOF node and the integrated CoTCPP complex, the strong nucleophilicity resulting from the incorporated imidazolium bromide-type IL, and the improved CO 2 adsorption capacity. Additionally, the CoTCPP-UiO-66-IL(BuImBr) catalyst exhibited excellent recyclability and broad substrate versatility in epoxide cycloaddition. These findings provide valuable insights into the development of multifunctional MOF-based heterogeneous catalysts with high activity and sustainability for CO 2 conversion applications.
研究领域:
材料科学
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催化化学
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环境科学
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DOI
高影响因子
Molecular Catalysis
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2020
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IF 3.687
Sihao Xu,Guojun Shi,Ya Feng,Chong Chen,Lijun Ji
Acetophenone is an important industrial intermediate and generally produced by the Friedel-Crafts acylation reaction, suffering from a low reactivity and serious equipment corrosion. Direct oxidation of ethylbenzene to acetophenone by molecular oxygen will be benign and cost-effective. The catalytic performance of NHPI/Co(II) herein was investigated by selective oxidation of ethylbenzene to acetophenone in different solvents at room temperature. The solvent hexafluoropropan-2-ol (HFIP) was found to markedly enhance the transformation efficiency from ethylbenzene to acetophenone in comparison with acetic acid, pyridine and ethanol, and the ethylbenzene conversion and the selectivity to acetophenone was high up to 87.9 % and 61.2 %, respectively. A higher concentration of phthalimide -N- oxyl (PINO) radicals was observed by an in situ electron paramagnetic resonance spectrometer (EPR) in HFIP with respect to other solvents, suggesting that HFIP may facilitate the generation of the N-oxyl radical and thus promote the selective oxidation of ethylbenzene to acetophenone. Furthermore, the benzylic carbon radical (PhCHCH 3 ) from ethylbenzene was trapped by tetramethylpiperidine N-oxyl radical (TEMPO) and observed by a high resolution mass spectrometer. The findings of both PINO and PhCHCH 3 under reaction conditions indicated that the selective oxidation of ethylbenzene to acetophenone catalyzed by NHPI/Co(II) should proceed via a radical mode. The selective oxidation of ethylbenzene to acetophenone using molecular oxygen by NHPI/Co(II) in HFIP exhibited an important industrial application prospect.
研究领域:
化学工程
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有机化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Yan Yu,Lele Zhou,Juntao Tang,Peng Wu,Li Feng,Beixiao Ge,Hui Chen,Jinxing Hu,Shuang Song,Tao Zeng
Adsorption of pollutants onto adsorbents is extremely important for water purification systems. In this study, the dynamic adsorption of radionuclides Co(II) and Sr(II) onto covalent triazine frameworks (CTFs) was explored. The effects of the adsorption conditions such as the amount of CTF (10, 25, and 50 mg), radionuclides concentrations (0.50–500.0 mg L −1 ), and adsorption temperature (293, 303, and 313 K) on the adsorption capacity was examined. Adsorption kinetics data were analyzed by using the pseudo-first-order and pseudo-second-order kinetic models. Langmuir and Freundlich models were used for analyzing adsorption isotherms. The results showed that the Langmuir isotherm and pseudo-second-order models described the experimental data better than the other models. The adsorption equilibrium time of CTF-N and CTF-B are 600 s and 200 s. The maximum monolayer adsorption capacity (q max ) of CTF-B and CTF-N for Co(II) were determined as 50.76 mg g −1 and 60.82 mg g −1 at 303 K. The q max of CTF-B and CTF-N for Sr(II) were 43.12 mg g −1 and 55.89 mg g −1 at 303 K. Thermodynamic analyses indicated that the adsorption process of Co(II) and Sr(II) onto CTF was spontaneous (ΔG < 0) and endothermic (ΔH > 0) and was favored at higher temperature.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Polymers
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2018
·Vol. 10
·期 9
·934
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IF 2.935
Guangqian Zhu,Xianhui Zhang,Mengmeng Zhao,Liang Wang,Chuyang Jing,Peng Wang,Xiaowu Wang,Qinggang Wang
A series of iminopyridine complexes of Fe(II) and Co(II) complexes bearing fluorinated aryl substituents were synthesized for the polymerization of isoprene. The structures of complexes3a,2band3bwere determined by X-ray diffraction analysis. Complex3acontained two iminopyridine ligands coordinated to the iron metal center forming an octahedral geometry, whereas2badopted a chloro-bridged dimer, and3bfeatured with two patterns of cobalt centers bridged via chlorine atoms. Complexes2band3brepresented rare examples of chlorine bridged bimetallic Co(II) complexes. The fluorine substituents effects, particularly on catalytic activity and polymer properties such as molecular weight and regio-/stereo-selectivity were investigated when these complexes were employed for isoprene polymerization. Among the Fe(II)/methylaluminoxane (MAO) systems, the 4-CF3substituted iminopyridine Fe(II) complex1awas found as a highly active isoprene polymerization catalyst exhibiting the highest activity of 106g·(mol of Fe)−1·h−1. The resultant polymer displayed lower molecular weight (Mn= 3.5 × 104g/mol) and moderate polydispersity index (PDI = 2.1). Furthermore, the ratio ofcis-1,4-/3,4 was not affected by the F substituents. In the series of Co(II)/AlEt2Cl binary systems, complexes containing electron-withdrawing N-aryl substituents (R = 4-CF3, 2,6-2F) afforded higher molecular weights polyisoprene than that was obtained by the complex containing electron-donating N-alkyl substituents (R = octyl). However, ternary components system, complex/MAO/[Ph3C][B(C6F5)4] resulted in low molecular weight polyisoprene (Mn< 2000) with hightrans-1,4-unit (>95%).Keywords:iminopyridine ligands;Fe(II);Co(II) complexes;isoprene polymerization;fluorinated aryl substituents
研究领域:
有机金属化学
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高分子科学
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催化
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产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
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2014
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IF 1.968
Shi Li,Shang-Ru Zhai,Qing-Da An,Ming-Hui Li,Yu Song,Xiao-Wei Song
The preparation of Co(II) supported magnetic heterogeneous catalyst, i.e. Fe 3 O 4 @SiO 2 –NH 2 @CS–Co, and its efficient and selective catalytic properties toward the oxidation of ethylbenzene to acetophenone are presented. The materials were characterized by various physicochemical techniques such as scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, elemental analysis, inductively coupled plasma-atomic emission spectrometer and X-ray photoelectron spectroscopy, etc. The reaction conditions were thoroughly investigated and highly improved catalytic performance (82.5% conversion of ethylbenzene and 80.1% selectivity to acetophenone) was gained under more mild reaction conditions of lower temperature (70 °C), shorter reaction period (60 min) and cheaper and greener oxygen source (H 2 O 2 ). More importantly, it could be reused successively at least 10 times when more than 80% of its catalytic activity maintained.
研究领域:
材料科学
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催化化学
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环境化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Yifei Niu,Jinjin Qian,Hongfang Hao,Dandan Zhao,Zichuan Ma,Xiaolong Ma
The application of carbon composite materials (CCMs) spans across various fields, and their preparation primarily involves the non-oxygen pyrolysis of non-volatile macromolecular precursors, which poses challenges in tailoring their composition and microstructure. Here, we propose a binary co-pyrolysis approach for the synthesis of CCMs, utilizing small organic molecules such as Phenanthroline (Phen), o -Phenylenediamine ( o PD), and Melamine (Mel) as precursors, along with Co(II) salt as a catalyst. We conducted a thermogravimetric analysis of these three binary systems, aiming to synthesize CCMs at moderate temperatures (330 − 460 °C). Subsequently, we characterized the CCMs in terms of their bulk structure, composition, and surface properties. Finally, we assessed their decontamination performance through catalytic H 2 O 2 degradation of methylene blue and adsorption of Pb(II)/phosphate. The results revealed that Co(II) can promote the preferential formation of thermally stable intermediate polymeric structures and inhibit the direct evaporation of the precursors. The prepared CCM-Phen-Co, CCM- o PD-Co, and CCM-Mel-Co exhibit a lamellar and (N, O, Co)–co-doped amorphous structure. Furthermore, both CCM-Phen-Co and CCM- o PD-Co demonstrate complete removal efficiency for methylene blue at a concentration of 10 mg/L, while the maximum adsorption capacity of CCM- o PD-Co for Pb(II) and CCM-Phen-Co for phosphate are 58.0 mg/g and 13.6 mg/g respectively. The CCMs demonstrate promising efficacy in environmental catalysis and adsorption for decontamination purposes.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
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2021
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IF 3.247
Donghai Yuan,Wanxia Liu,Jiazhuo Wang,Jun Cui,Liansheng He,Chenling Yan,Yingying Kou,Junqi Li
In this study, an efficient adsorption and reusable magnetic ligand material (Fe3O4@Chitosan-EDTA) was synthesized by binding EDTA dianhydride onto magnetic chitosan, and it was employed in removal of Co(II) from aqueous solution. The maximum adsorption capacity of Co(II) onto Fe3O4@CS-EDTA was 48.78 mg/g at pH = 5 (303 K), which is much higher than that of Fe3O4@Chitosan as well as chitosan. The kinetics of Co(II) on the Fe3O4@CS-EDTA was consistent with the pseudo-second-order model. The equilibrium data were better fit with the Langmuir isothermal model than with the Freundlich isothermal model, suggesting that the adsorption mechanism was chemical monolayer homogeneous adsorption. The thermodynamic data showed that the sorption of Co(II) was spontaneous. Furthermore, after four cycles, the adsorption capacity of Co(II) onto the Fe3O4@CS-EDTA still retained 84.5% of the capacity of the fresh adsorbent, indicating that Fe3O4@CS-EDTA can be considered a promising recyclable adsorbent to remove heavy-metal ions from wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Qiyuan Zheng,Zuoying Cao,Shengxi Wu,Qinggang Li,Mingyu Wang,Wenjuan Guan,Guiqing Zhang
As the production and consumption of lithium-ion batteries increase, high purity Ni(II) and Co(II) products are becoming increasingly critical as key raw materials for battery cathodes. However, the clean and efficient separation of Ni(II) and Co(II) has been a bottleneck problem since they often coexist in ores and secondary resources and have similar ionic radii, oxidation states, and coordination numbers. Thus, this paper proposes a novel extractant (NNPA) and a breakthrough method to separate Ni(II) and Co(II). The effects of chloride ion concentration , pH value, temperature, O/A ratio and extraction time on extractant selectivity and extraction efficiency were investigated. Under optimum conditions, NNPA demonstrated high extraction ability (E = 94.6 %) and selectivity (β Ni(II)/Co(II) = 481) for Ni(II) at pH 0, whereas at pH 6, it has high extraction ability (E = 93.9 %) and selectivity (β Co(II)/Ni(II) = 510.88) for Co(II). To provide in-depth insights into the Ni(II) and Co(II) separation mechanism, based on the single crystal XRD analyses of the extracted Ni(II) complex and the extracted Co(II) complex, DFT calculations were performed. The results show that the extraction order of NNPA is NNPANiHCl 3 > NNPACoCl 2 > NNPANiCl 2 (H 2 O) 2 . Due to the different selectivity of NNPA towards Ni(II) or Co(II) at different pH values, it is able to greatly reduce the consumption of extractant and significantly shorten the extraction process flow by selectively extracting the low concentration Ni(II) or Co(II) from Ni(II)-Co(II) solutions, thereby improving efficiency, reducing energy consumption and achieving cleaning production.
研究领域:
化学工程
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材料科学
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环境科学
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产品关联
DOI
高影响因子
LANGMUIR
·
2024
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IF 3.7
Yinyin Peng,Ting Pan,Chuang Chen,Yuchen Zhang,Guoyuan Yuan,Derong Liu,Xiaoqin Pu,Wei Xiong
In this study, researchers developed a novel composite material called NH2-MIL-53-Al/PAN, which consists of metal–organic frameworks (MOFs) grown on electrospun PAN nanofibers (NFs). The successful formation of the composite was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR), and the hydrophilicity of NH2-MIL-53-Al/PAN was demonstrated by the water contact angle (WCA). Batch experiments were conducted to investigate the adsorption performance of Co(II) under different conditions. The maximum adsorption capacity reached 58.72 mg/g, and almost 95% of the adsorption was achieved within the first 6 h. The adsorption process was found to be spontaneous and endothermic and followed the pseudo-second-order kinetics and Langmuir models. Chemisorption and molecular layer adsorption are the main mechanisms of adsorption, and X-ray photoelectron spectroscopy (XPS) analysis further reveals that the interaction between the adsorbent and cobalt is a coordination interaction. In this study, NH2-MIL-53-Al was grown in situ on PAN to ensure effective loading of MOFs and prevent agglomeration during the NF mixing process. This approach successfully addressed the challenge of exposing active sites within the embedded MOF crystals. Additionally, it overcame the difficulty of recycling traditional MOF adsorbents. As a result, the exceptional performance of MOF NFs offers a promising solution for the efficient removal of cobalt-containing wastewater.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2018
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IF 2.631
Sheng Zhang,Xiaxia Song,Guowei Lin,Qi Yang,Quan Shi,Hui Zheng,Xin Liu,Qing Wei,Gang Xie,Sanping Chen,Shengli Gao
In this paper, two new H 2 ZTO-Co(II) coordination polymers (H 2 ZTO = 4,4′-azo-1,2,4-triazol-5-one), [Co(H 2 ZTO) 2 (H 2 O) 4 ](NO 3 ) 2 (1) and {[Co(H 2 ZTO)(H 2 O) 4 ](NO 3 ) 2 ·2H 2 O} n (2), have been synthesized and characterized. Polymer 2 is derived from 1 and undergoes a multistage transformation by soaking 1 in distilled water. X-ray single crystal structure analyses showed that 2 exhibit a one-dimensional (1D) chain geometry coordinated by 0D units of 1 through uncoordinated nitrogen atoms of H 2 ZTO ligands. The thermal decomposition behaviors and magnetic properties of 1 and 2 were discussed. In addition, the low-temperature (1.9–300 K) heat capacities of 1 and 2 were measured using the heat capacity option of a Quantum Design Physical Property Measurement System (PPMS). The thermodynamic functions of 1 in the experimental temperature range were derived by fitting the heat capacity data to a series of theoretical and empirical models. Using the fitted heat capacity results, the standard molar entropy and standard molar enthalpy have been respectively calculated to be (871.1 ± 8.7) J·mol −1 ·K −1 and (132.7 ± 1.3) kJ·mol −1 for 1 .
研究领域:
化学
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材料科学
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物理化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）