Catalysis Science & Technology
·
2022
·Vol. 12
·期 21
·6437-6443
·
IF 6.177
Xingyu Lu,Ke Qi,Di Wang,Xueya Dai,Wei Qi
2,5-Furandicarboxylic acid (FDCA) is a high-value platform molecule that can replace the fossil derivative terephthalic acid in the synthesis of important chemicals. FDCA can be synthesized from the oxidation of the biomass derivative 5-hydroxymethylfurfural (HMF). In this study, we loaded Cu-based catalysts with different morphologies and chemical states on carbon paper, and it was found that the Cu nanocrystalline/carbon paper catalyst with a thin and scattered dendrite structure (Cu(NSD)/CP) exhibits the best performance for the electrooxidation of HMF (96% yield and 100% selectivity for FDCA), which is attributed to the fact that the Cu0 and Cu1+ species in the catalyst are easily oxidized in situ to Cu2+ species, showing high catalytic activity during the reaction process. This paper highlights the importance of the identification of active sites and the rational design of catalysts based on structure–function relations.
研究领域:
催化化学
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电化学
·
材料科学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2016
·
IF 2.653
Xue-Dong Xiao,Lin Shi,Li-Hui Guo,Jun-Wen Wang,Xiang Zhang
The supramolecular interaction between the water-soluble pillar[5]arene (WP[5]) as host and dopamine hydrochloride (DH) as guest was studied by spectrofluorometry . The fluorescence intensity of DH gradually decreased with increasing WP[5] concentration, and the possible interaction mechanism between WP[5] and DH was confirmed by 1 H NMR, 2D NOESY , and molecular modelling. Based on significant DH fluorescence, a highly sensitive and selective method for DH determination was developed for the first time. The fluorescence intensity was measured at 312 nm, with excitation at 285 nm. The effects of pH, temperature, and reaction time on the fluorescence spectra of the WP[5]-DH complex were investigated. A linear relationship between fluorescence intensity and DH concentration in the range of 0.07–6.2 μg mL − 1 was obtained. The corresponding linear regression equation is Δ F = 25.76 C + 13.56 (where C denotes the concentration in μg mL − 1 ), with the limit of detection equal to 0.03 μg mL − 1 and the correlation coefficient equal to 0.9996. This method can be used for the determination of dopamine in injection and urine samples. In addition, the WP[5]-DH complex has potential applications in fluorescent sensing and pharmacokinetics studies of DH.
研究领域:
分析化学
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超分子化学
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药物代谢
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生物分析
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药代动力学
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2020
·
IF 4.551
Jing Hao,Dang-guo Cheng,Fengqiu Chen,Xiaoli Zhan
To explore the effect of channel properties on catalytic activity, ZSM-5 zeolite nanosheets were synthesized with di-quaternary ammonium-type surfactant and used in n-heptane cracking reaction. Nanosheet thickness was changed from around 4 nm–20 nm by adjusting the ratio of surfactant to tetraethyl orthosilicate (TEOS). The synthesized zeolite nanosheets were characterized by physical and chemical adsorption , electron microscopy , X-ray diffraction (XRD), pyridine infrared (Py-IR), Thermogravimetric analysis (TGA) and Raman spectra. The results showed that zeolite with thicker nanosheets had more microporosity and was more conducive to remarkably improving the selectivity of light olefins . High mesoporosity of zeolite nanosheets greatly reduces the diffusion resistance and accelerates mass transfer which even increases the direct diffusion of insufficiently cracked intermediates. Thicker zeolite nanosheets with more micropores prolong the reaction time and thus improve the selectivity of target products.
研究领域:
催化化学
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材料科学
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石油化工
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多相催化
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纳米材料
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xinhui Liu,Chen Yan,Yilin Wang,Peng Zhang,Siyan Yan,Hanbin Wang,Jianguo Zhuang,Yitao Zhao,Yuchen Wang,Yijun Yu,Qichao Zhao,Xuedong Zhu,Fan Yang
A series of Zn loaded ZSM-5 (Zn/ZSM-5) zeolites were prepared utilizing either Zn(NO 3 ) 2 or Zn-based MOFs (ZIF-61, ZIF-8 and ZIF-14) as Zn sources to explore their effects on the catalysts’ physiochemical properties through characterizations and simulations. Results revealed that hierarchical structures containing meso - to macro- pores of 10 ∼ 80 nm aside from the intrinsic micropores were constructed profiting from the use of Zn-based MOFs. On the other side, lager proportions of medium acid and Lewis acid sites were generated by more Zn(OH) + , whose content was proven to be inextricably linked to the binding energy between Zn and ligand as well as local charge valence state of Zn. Benefitting from hierarchical structures and balanced acidities, Zn/Z5(ZIF-14) employing ZIF-14 as Zn source demonstrated higher aromatic selectivity and longer catalyst lifetime (50.9 % and 26 h) than the microporous counterpart synthesized from zinc nitrate hexahydrate (42.1 % and 20 h) in methanol to aromatics (MTA) reaction.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Deyu Si,Meihua Zhu,Xinmei Sun,Miao Xue,Yuqin Li,Ting Wu,Tian Gui,Izumi Kumakiri,Xiangshu Chen,Hidetoshi Kita
The formation progress of the high aluminum ZSM-5 zeolite membrane was investigated and characterized with the organic template-free and fluoride-containing initial synthesis gel. The nano spherical Silicalite-1 seed crystals were dissolved into amorphous by the fluoride-containing precursor synthesis gel. The amorphous contained elementary structural units (TO 4 ) and isolated five-membered ring structure of MFI zeolites. These were retained to provide the nucleation sites for high aluminum ZSM-5 zeolite. The ZSM-5 zeolite nucleus was grown into fine needle-like ZSM-5 zeolites, which were gradually grown into twin crystals, aggregation and compact ZSM-5 zeolites layer on the support without the organic template initial synthesis gel. In addition, the high aluminum ZSM-5 zeolite membranes kept the identical morphology and structure for separation of high concentration acetic acid (H 2 O/HAc) or inorganic acid (1 M H 2 SO 4 ) aqueous mixtures by XRD, SEM and NMR characterization. Furthermore, the membrane had a good dehydration performance and acid-stability by pervaporation. The flux and separation factor of the membrane for 10 wt% H 2 O/HAc mixtures were 0.98 kg∙m −2 ∙h −1 and 3200 at 348 K, respectively.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 12
·3505-3513
·
IF 2.482
Zhang Huifa,Geng Tong,Zhang Huixian,Cao Fahai
Abstract 5-Hydroxymethylfurfural (HMF) is mainly produced by dehydration of hexasaccharides which were limited by the source availability and low yield of the process. Accounting to this, the current study was thus designed to first identify the mesoporous niobium phosphate was a tailored catalyst and further to develop a suitable reaction system for hydroxymethylation of furfural to HMF. The mesoporous niobium phosphate was prepared by a two-step sol–gel hydrothermal method used to catalyze this hydroxymethylation reaction either in a pure water solvent or in an aqueous organic solvent system. Detailed investigation on reaction activity and HMF selectivity was carried out by varying reaction conditions. A highest HMF yield of 51.1% was obtained with a 79.2% furfural conversion under the aqueous dimethyl sulfoxide (DMSO) at 90 °C for 20 h over the current catalyst. Moreover, the mesoporous niobium phosphate could be recovered and reused at least for 6 runs without obvious loss in catalytic activity. Grpahic Abstract Mesoporous niobium phosphate was synthesized by a two-step sol–gel hydrothermal method and firstly investigated for the catalytic hydroxymethylation of furfural to HMF. The results suggest that mesoporous niobium phosphate shows a superior activity and selectivity. The highest yield of 51.1% of HMF was obtained with a 79.2% furfural conversion. The excellent catalytic performance could be attributed to attributed to the strong acid sites and larger porous structure in the catalyst.
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产品关联
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2018
·Vol. 22
·期 3
·129-135
·
IF 3.081
Zhang Di,Zhao Yun-Peng,Fan Xing,Liu Zhong-Qiu,Wang Rui-Yu,Wei Xian-Yong
A series of Ni/HZSM-5 catalysts with different Ni-loadings and Si/Al ratios were prepared by incipient wetness impregnation and employed for catalytic hydrogenation of levulinic acid (LA) to gamma-valerolactone (GVL). Their physicochemical properties were characterized by X-ray diffraction, nitrogen adsorption–desorption, X-ray photoelectron spectrometer, temperature-programmed desorption of ammonia,transmission electron microscopy, temperature-programmed reduction of hydrogen, and pyridine-adsorbed infrared spectroscopy. The diffraction peaks assigned to Ni phase were not observed, implying that nickel particles were small and had a high dispersion on the supports. The catalysts with a strong acidity and the appropriate ratio of Brönsted (B) acid sites to Lewis (L) acid sites (B/L = 4.9) show an excellent activity and selectivity for the hydrogenation of LA to GVL. High conversion of LA and selectivity towards GVL were achieved over 5 wt% Ni/HZSM-5-50. The maximum GVL yield of 100% over 5 wt% Ni/HZSM-5-50 was obtained under the optimized reaction conditions of 210 °C, 2 h, and 3 MPa initial hydrogen pressure.
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 22
·期 3
·577-584
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IF 1.108
Zhao Xinhong,Wen Juanjuan,Zhao Jiangbo,Li An,Li Guixian,Wang Xiaolai
Hierarchically structured SAPO-5 molecular sieve was synthesized by microwave-assisted ionothermal method in eutectic mixture solvent. Their porous texture and acid properties were characterized by nitrogen physisorption, SEM, TEM and NH 3 -TPD. The results show that the mesoporous volume of SAPO-5 can be tuned via simply varying the degree of supersaturation, the type of mineralizer or replacing partly succinic acid with sebacic acid. A lower degree of supersaturation and using ammonium fluoride as a mineralizer favor the synthesis of SAPO-5 with large mesoporous volume. Notably, the introduction of sebacic acid can lead to three-level micro-meso-macroporous structure (sample C1). Five typical samples were selected as catalysts and tested in the alkylation of benzene with benzyl alcohol. Among all catalysts, the sample C1, whose aspect ratio is the lowest, exhibited the best catalytic activity, giving a 91 % benzyl alcohol conversion. The diffraction peak intensity ratio of I 002 /I 100 was proposed to be a good indicator in fabricating a highly active SAPO-5 catalyst for this reaction.
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 106
·104398-104406
·
IF 3.289
Cong Zhang,Jingbo Qi,Jing Xing,Si-Fu Tang,Liang Song,Yuanyuan Sun,Chuanhui Zhang,Hongchuan Xin,Xuebing Li
Aqueous phase catalytic upgrading of lignin monomers to hydrocarbons via hydrodeoxygenation (HDO) has been explored using a combination of Pd/C and HZSM-5 catalysts under 2 MPa of H2 (ambient temperature). Model monomers with varying numbers of methoxy groups, including phenol, anisole, guaiacol and 2,6-dimethoxy-phenol, were chosen as lignin model compounds. Mechanistic studies revealed cascade and parallel reaction pathways via hydrogenation and dehydration (hydrolysis) processes, which were catalyzed by Pd/C and HZSM-5, respectively. Hydrogenation was preferred at lower temperature, whereas higher temperature was favorable for the removal of oxygen-containing functional groups. The effect of methoxy groups on the HDO of these monomers was also investigated systematically. Basically, the conversion of multi-substituted monomers was tougher than that of mono-substituted ones, due to steric constraint and the inhibition of the electron-donating hydroxyl group. The selectivities to cyclohexane from phenol and anisole were improved significantly by increasing the temperature to 413 K. However, cyclohexanone was preferably produced over cyclohexane when using model compounds with multi-substituents (guaiacol and 2,6-dimethoxy-phenol), even at temperatures above 513 K. Comparative experiments were also conducted on the HDO of 1,2-cyclohexanediol with or without the presence of phenol, which clearly suggested that the further HDO of guaiacol and 2,6-dimethoxy-phenol was inhibited, probably due to the strong interactions between cyclohexanediol molecules and Brønsted acid sites.
研究领域:
化学工程
·
催化反应
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Wanzhen Zhu,Yu Meng,Chaoxin Yang,Jun Zhao,Hongliang Wang,Wei Hu,Guangqiang Lv,Yingxiong Wang,Tiansheng Deng,Xianglin Hou
As the frontier in heterogeneous catalyst, a monomer and positively charged active sites in the single-atom catalyst (SAC), anchored by high electronegative N, O, S, P, etc., atoms, may not be active for the multispecies (O2, substrates, intermediates, solvent etc.) involved liquid-phase aerobic oxidation. Here, with catalytic, aerobic oxidation of 5-hydroxymethylfurfural as an example, Pt SAC (Pt1-N4) was synthesized and tested first. With commercial Pt/C (Pt loading of 5 wt %) as a benchmark, 2,5-furandicarboxylic acid (FDCA) yield of 97.6% was obtained. Pt SAC (0.56 wt %) gave a much lower FDCA yield (28.8%). By changing the coordination atoms from highly electronegative N to low electronegative Co atoms, the prepared Pt single-atom alloy (SAA, Pt1-Co3) catalyst with ultralow Pt loading (0.06 wt %) gave a much high FDCA yield (99.6%). Density functional theory (DFT) calculations indicated that positively charged Pt sites (+0.712e) in Pt1-N4 almost lost the capability for oxygen adsorption and activation, as well as the adsorption for the key intermediate. In Pt1-Co3 SAA, the central negatively charged Pt atom (−0.446e) facilitated the adsorption of the key intermediate; meanwhile, the nearby Co atoms around the Pt atom constituted the O2-preferred adsorption/activation sites. This work shows the difference between the SAC with NPs and the SAA during liquid-phase oxidation of HMF and gives a useful guide in the future single-atom catalyst design in other related reactions.
研究领域:
催化化学
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材料科学
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理论计算化学
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DOI
高影响因子
ChemCatChem
·
2013
·Vol. 5
·期 6
·1517-1523
·
IF 5.181
Yan Liu,Xiaozhao Zhou,Xinmei Pang,Yinying Jin,Xiangju Meng,Xiaoming Zheng,Xionghou Gao,Feng-Shou Xiao
Graphical Join the chain gang: Chain-like ZSM-5 crystals that are synthesized in the presence of starch show higher p -xylene selectivity in m -xylene isomerization than normal, mesoporous, and sheet-like ZSM-5 crystals. ZSM-5 zeolite crystals with controllable b- axis length (sheet-like, S-ZSM-5; chain-like, C-ZSM-5) have been synthesized by using urea and starch as additives in the starting aluminosilicate gels. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images show that these zeolite samples have good crystallinity. Transmission electron microscopy (TEM) images show that there is a strong chemical interaction between the stacked crystals in C-ZSM-5 samples. N 2 sorption isotherms indicate that C-ZSM-5 crystals are mesoporous. Catalytic tests for the formation of p -xylene from m- xylene isomerization show that, compared with other zeolite catalysts, C-ZSM-5 catalysts give both high conversion and improved p -xylene selectivity, which are attributed to the combination of relatively long b -axis length and the present mesoporosity in the crystals. The improvement of p -xylene selectivity in catalytic m- xylene isomerisation is of great importance for selective industrial production of p -xylene in the future.
研究领域:
化学工程
·
材料科学
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2019
·
IF 3.834
Yunlei Zhang,Bing Li,Yanan Wei,Changhao Yan,Minjia Meng,Yongsheng Yan
Developing a green and economically viable approach for the direct synthesis of metal-organic frameworks (MOFs) catalysts with multifunctional active sites remains the key step for their applications in heterogeneous catalysis field. Herein, we report a green (aqueous solutions), mild (90 °C, atmospheric pressure), and modulated hydrothermal (MHT) approach to synthesize UiO-66-type MOFs catalysts with acid–base bi-functional sites, which were obtained via the coordination of monosodium 2-sulfoterephthalate and 2-aminoterephthalic with zirconium (Zr) ions. More importantly, a series of acid, base and acid–base catalysts with varied acid–base strengths can be readily prepared, by simply varying the ratio of organic ligands for preparing MOFs. The synthesized catalysts were characterized and their performances in glucose dehydration to produce 5-hydroxymethylfurfural (5-HMF) have been evaluated. The developed approach in this work has clearly depicted a roadmap for the facile synthesis of MOFs catalysts to facilitate their potential use in acid–base catalysis.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）