ENVIRONMENTAL TECHNOLOGY
·
2023
·
IF 2.8
Jiaying Zhu,Yanyang Wu,Bin Wu,Kui Chen,Lijun Ji
m-Cresol and p-cresol are widely used in medicine and pesticides as important chemical intermediates. They are generally produced as a mixture in industry and are difficult to separate due to the similarities in both chemical structures and physical properties. The adsorption behaviours of m-cresol and p-cresol on zeolites (NaZSM-5 and HZSM-5) with different Si/Al ratios have been compared by static experiments. Selectivity on NaZSM-5(Si/Al = 80) could be greater than 6.0. Adsorption kinetics and isotherms were investigated in detail. The kinetic data was correlated by PFO, PSO, and ID models, the NRMSE of which were 14.03%, 9.41%, and 21.11%, respectively. In the meanwhile, according to the NRMSE of Langmuir (6.01%), Freundlich (57.80%), D-R (1.1%), and Temkin (0.56%) isotherms, adsorption on NaZSM-5(Si/Al = 80) was mainly a monolayer and chemical adsorption process. It was endothermic for m-cresol and exothermic for p-cresol. The Gibbs free energy, entropy, and enthalpy were calculated accordingly. The adsorption of cresol isomers on NaZSM-5(Si/Al = 80) were both spontaneous, and it was exothermic (ΔH = −37.11kJ/mol) for p-cresol while endothermic (ΔH = 52.30kJ/mol) for m-cresol. Additionally, ΔS were respectively −0.05 and 0.20 kJ·mol−1·K−1for p-cresol and m-cresol, which were both close to zero. The adsorption was mainly driven by enthalpy. The result of breakthrough further demonstrated m-cresol and p-cresol could be separated effectively by NaZSM-5(Si/Al = 80). Additionally, the selectivity increased from 7.53 to 14.72 after four cycles regeneration with 9.95% and 53.96% decreases in the adsorption amounts for m-cresol and p-cresol, respectively. In conclusion, NaZSM-5(Si/Al = 80) could be a feasible adsorbent for the separation of m-cresol and p-cresol.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2025
·
IF 2.3
Caidi Zhang,Wanchuan Shang,Xiaoning Zhang,Xueli Huang,Xueying Wang
Cresol is an important phenolic compound derived primarily from low-temperature coal tar. The presence of m/p-cresol increases the unsaturated bonds in coal tar. This increases the hydrogen consumption in the hydrogenation process. Separation and further purification of m/p-cresol can improve the value of coal tar. The boiling points of m-cresol and p-cresol are similar and therefore difficult to separate. It has become a major problem in the development of crude phenol refining. In this work, a novel complexing agent, hexamethylenetetramine, was used to complex and separate cresols. The effects of crystallization temperature, complexing agent dosage, solvent dosage and crystallization time were investigated. The process was optimized using response the surface methodology. As a result, the purity of m-cresol could reach more than 94.2% and the yield reached more than 30.4%, indicating that the process could effectively separate the mixture of m-cresol and p-cresol.
研究领域:
化学工程
·
煤化工
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 55
·期 4
·1614-1626
·
IF 3.442
Pan Liuyi,He Yulong,Niu Menglong,Dan Yong,Li Wenhong
Ni 2 P catalysts supported on different supports, such as SiO 2 from different sources, Al 2 O 3 , TiO 2 and ZrO 2 were prepared for the hydrodeoxygenation of p-cresol (monocyclic phenol model in coal tar). The reaction was carried out on a fixed-bed reactor at a temperature of 330–390 °C under 2 MPa. The order of conversion of p-cresol was as follows: Ni 2 P/SiO 2 -2 > Ni 2 P/SiO 2 -3 > Ni 2 P/SiO 2 -1 > Ni 2 P/Al 2 O 3 > Ni 2 P/ZrO 2 > Ni 2 P/TiO 2 . Ni 2 P/SiO 2 -3 shown higher DDO path selectivity, resulting in the conversion of p-cresol of 93% and a selectivity of 72.6% for BTX products under the reaction temperature of 370 °C with LHSV of 0.5 h −1 . This catalyst was also used for the hydrodeoxygenation of the crude phenolic mixture extracted from coal tar, which shown that the phenol deoxidation rate was 87.6% and the BTX product selectivity was 73.7% by GC–MS.
研究领域:
化学工程
·
催化反应
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DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Bowen Wu,Yixi Chen,Mingtai Liu,Yi Tang,Gengfeng Zheng,Linping Qian
The surface properties of CoMg/Al 2 O 3 were evaluated in the aerobic oxidation of p -cresol. The surface interaction is enhanced greatly after Co and Mg impregnation with the mole ratio of Co/Mg from 2 : 1 and 2 : 3. The strongest interaction for the nonpolarity and benzene ring was found on CoMg/Al 2 O 3 with Co/Mg of 2 : 3. But for the interaction with p -π group bonding with negative anion, the highest value appears on the catalyst with the Co/Mg of 2 : 2. In aerobic oxidation of p -cresol, the conversion is significantly increased with Co addition and reaches around 60 % after 24 h' reaction at 338 K. The highest selectivity of p -hydroxybenzaldehyde of 99 % is achieved on Al 2 O 3 with the co-impregnation mole ratio of Co/Mg of 2 : 2. It is suggested that medium adsorption of the reactants and strong stabilization of the intermediates facilitate the aerobic oxidation of p -cresol to p -hydroxybenzaldehyde.
研究领域:
催化化学
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材料科学
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有机化学
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产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 37
·21175-21185
·
IF 3.049
Liuyi Pan,Yulong He,Menglong Niu,Yong Dan,Wenhong Li
Ni–M/SiO2 with different binary metals M (M = Ce, Co, Sn, Fe) prepared by an incipient impregnation method was used in the hydrodeoxygenation (HDO) of low-temperature coal tar distillate, which is rich in phenolic compounds. p-Cresol, as a model compound of the distillate, was used to evaluate the activity and selectivity of BTX products on the series of reduced Ni–M/SiO2 catalysts in a fixed bed reactor. The properties of the catalysts were characterized by N2 adsorption–desorption, ICP-AES, XRD, H2-TPR, and XPS. Benzene and toluene as the direct deoxygenation (DDO) products and cyclohexane and methylcyclohexane as the hydrogenolysis (HYD) products were detected to evaluate the selectivity of the path in the deoxygenation process. In this series of catalysts, the order of reactivity was Ni–Ce > Ni–Sn > Ni–Co > Ni–Fe > monometallic Ni. Meanwhile, the addition of Ce and Co loaded in the Lewis acid sites of the catalyst affected the electron distribution of nickel atom and its atomic arrangement on the surface of the carrier. Compared to monometallic Ni, the DDO path become dominant on Ni–Ce and Ni–Co and the selectivity for BTX products increased from 58.8% to 77.4% and 71.1%, respectively. The binary metal Sn, unlike the former two metals, formed a Ni3Sn crystal form with Ni, which resulted in significant enhancement of the HYD path while obviously increasing the reactivity.
研究领域:
化学工程
·
催化材料科学
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DOI
PubMed
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 1.9
Xudong Wang,Yanyang Wu,Tianyou Wang,Bin Wu,Kui Chen,Lijun Ji
M-cresol and p-cresol, typically produced as mixtures in industrial processes, are crucial chemical intermediates. However, their separation is challenging due to their similar structures and properties. ZSM-5 zeolite has shown potential as an adsorbent for separation, while the performance is yet to be improved. In this study, ZSM-5-F(x) was synthesized via hydrothermal method, incorporating F − ions during the synthesis process. The adsorption behaviour of m-cresol and p-cresol on ZSM-5-F(x) was investigated through static experiments, with ZSM-5-F(8) demonstrating the highest selectivity (9.01). Both ZSM-5-F(0) and ZSM-5-F(8) were characterized using XRD, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) techniques. In addition, the introduction of F − ions increased the material's electronegativity, as demonstrated by the change in zeta potential from 53.22 to −45.93 mV. Single-component adsorption of m-cresol or p-cresol on ZSM-5-F(0) and ZSM-5-F(8) respectively were investigated in detail. The adsorption of m-cresol on ZSM-5-F(8) showed a non-monotonic phenomenon with a significant decrease after 0.06 mol/L. The thermodynamic parameters including Δ G , Δ H , and Δ S were calculated accordingly. All the values |Δ G |, |Δ H |, and |Δ S | of both components on ZSM-5-F(8) were greater than those on ZSM-5-F(0), suggesting that the introduction of F − ions facilitated the adsorption. Competitive adsorption experiments on both ZSM-5-F(0) and ZSM-5-F(8) were conducted at 298.2 K. The results indicated that the selectivity α p/m on ZSM-5-F(8) increased with increasing initial concentration and laid between 13 and 14. After seven consecutive regeneration cycles, the selectivity (α p/m ) only decreased to 13. This study suggests that ZSM-5-F(8) could be a promising adsorbent for m-cresol and p-cresol in industrial applications.
研究领域:
化学工程
·
材料科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Cheng Liang,Xuefeng Li,Diefeng Su,Qiyi Ma,Jianyong Mao,Zhirong Chen,Yong Wang,Jia Yao,Haoran Li
Efficient aerobic oxidation has been developed for the selective preparation of a sequence of valuable p -hydroxybenzaldehydes from corresponding p -cresols, using a new magnetically separable catalyst of nano-structured cobalt–cobalt oxide/nitrogen-doped carbon (CoO x @CN) material. CoO x @CN showed high activity for the 2-methoxy-4-cresol oxidation to vanillin, giving great yield (90%) and with good turnover number (210), as well as other p -cresols in good to great yields. The catalytic performance was investigated and related to the structural, chemical and magnetic properties which determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometer (VSM). The effects of base to substrate molar ratio, catalyst concentration, temperature, and solvent on the conversion and selectivity patterns also have been studied. The investigation revealed that remarkable catalytic properties of CoO x @CN could be ascribed to the active species cobalt oxide, doped nitrogen and porous carbon with large surface area. The size of the catalyst is a key factor for catalyst performance. The ferromagnetic property of catalyst enables to recycle easily by an external magnetic field and reuse six successive times without significant activity loss.
研究领域:
材料科学
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催化化学
·
纳米技术
✓ 已验证
产品关联
DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xiaoling Liu,Xiaoli Hou,Yijin Zhang,Hong Yuan,Xinlin Hong,Guoliang Liu
Catalytic hydrodeoxygenation (HDO) of phenolics to aromatics is one of the most important reaction routes in bio-oil upgrading. Sulfided CoMo catalysts are good candidates for this reaction, but their activities are strongly associated with the number of exposed surface sites and Co–Mo synergy. Herein, we employ zeolitic imidazolate framework-67 as a cobalt precursor and template for inverse deposition of MoS2 ultrathin sheets inside the framework to form CoMoS interfaces by using a simple hydrothermal method. The size-confined MoS2 possesses a few-layered structure and abundant surface defects. It is found that in situ generation of a CoMoS active phase would take place to reach the best activity of our catalysts under the HDO reaction condition or by H2 prereduction treatment. With varying different Co–Mo molar ratios, the optimized CoMoS-0.18 catalyst exhibits the highest HDO activity, with a p-cresol conversion of 92.4% and a toluene selectivity of 95.5% at 250 °C. The high performance is ascribed to the formation of an accessible surface CoMoS phase after surface restructuring.
研究领域:
催化化学
·
生物质能升级
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 7
·1-10
·
IF 6.232
Li Shanshan,Zhang Yintang,Mu Shuai,Ma Minrui,Liu Xiaoyan,Zhang Haixia
A novel magnetic organic porous polymer (denoted as Fe 3 O 4 @PC-POP) was developed for magnetic solid-phase extraction (MSPE) of two gastric cancer biomarkers (P-cresol and 4-hydroxybenzoic acid) from urine samples prior to high-performance liquid chromatographic analysis. The adsorbent was characterized by scanning electron microscope, transmission electron microscope, FTIR, powder X-ray diffraction, and other techniques. The result of dynamic light scattering shows that the particle size of the adsorbent is mainly distributed around 400 nm. Based on the design concept of the Fe 3 O 4 @PC-POP, the proposed material can effectively capture the target analytes through electrostatic and hydrophobic interaction mechanism. Furthermore, the enrichment conditions were optimized by the response surface method, and the method was utilized for the determination of P-cresol and 4-hydroxybenzoic acid in real urine samples from health and gastric cancer patients with high enrichment factors (34.8 times for P-cresol and 38.7 times for 4-hydroxybenzoic acid), low limit of detection (0.9–5.0 μg L −1 ), wide linear ranges (3.0–1000 μg L −1 ), satisfactory relative standard deviation (2.5%–8.5%), and apparent recoveries (85.3–112% for healthy people’s and 86.0–112% for gastric cancer patients’ urine samples). This study provides a guided principle for design of the versatile polymer with specific capturing of the target compounds from complex biological samples.
Graphical abstract
研究领域:
分析化学
·
医学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子