NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 32
·13755-13763
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IF 3.288
Xia Wang,Wulan Zeng,Wenjing Liu,Xiaoyu Cao,Chunhui Hou,Qi Ding,Yaxuan Lü
The design and development of low-cost sorbents is vital for CO2 capture from flue gases. In this study, the lignite char from Ordos coal (SE) was treated by a one-step KOH activation method to prepare microporous activated carbons for CO2 adsorption. The textural pore properties, surface functional groups and element contents of SE before and after activation were characterized and discussed; the effects of the mass ratio of KOH to SE, activation temperature and time, as well as the adsorption temperature on CO2 adsorption for prepared porous sorbents were investigated and optimized; the isosteric heat of adsorption and adsorption kinetics for the optimized sorbent were further calculated and fitted. When the mass ratio of KOH to SE was 1 : 1, the activation temperature and time were 700 °C and 120 min respectively, and the sorbent of K/SE700(120) showed an adsorption capacity of 1.35 mmol g−1 at 20 °C, which dropped by 2.96% after ten regenerations. The Langmuir adsorption isotherms fitted the adsorption data of K/SE700(120) well, and the isosteric heats of adsorption were 11–13 kJ mol−1, showing the physisorption characteristic. In addition, the good fit of the adsorption data to the Avrami model suggested that there are multiple adsorption routes for K/SE700(120).
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
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Fengqin Li,Jingjie Zhou,Yuqi Liu,Jinyuan Sun,Ke Zhang,Huibin Liang,Chunyu Wang,Tao Geng,Riccardo Tesser,Vincenzo Russo,Martino Serio
The reaction of butylene oxide with fatty alcohols produces interesting products for the surfactant industry; however, no detailed study on the kinetics of this reaction can be found in the literature. In this paper, the kinetics of butoxylation of dodecanol catalyzed by KOH was deeply investigated. An orthogonal design approach was used to determine the optimum reaction conditions, which were analyzed in conjunction with the residues of fatty alcohols and epoxidized butanes by using a combined metric analysis. On this basis, BO solubility was measured and finally compared with the UNIFAC model, and it was found that the kinetics of epoxidized butane was modeled in the same way as the ethoxylation and propoxylation of primary fatty alcohols. It is concluded that the alkoxylation reaction rate decreases mainly with the increase in the steric hindrance of the employed epoxide. Finally, the models and data in this paper can be used for industrial reactor design and production optimization.
研究领域:
化学工程
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表面活性剂工业
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
·
IF 9.5
Bin Hu,Min Liu,Qinghai Chen,Xiaowei Zhou,Hongjing Li,Meizi He,Zhongyan Li,Rong Zhang,Yingda Huang,Tauqir A. Sherazi,Nanwen Li
The porosity of polybenzimidazole (PBI) based ion-solvating membranes (ISM) with thin skin layer is controlled and utilized to enhance its capacity for electrolyte absorption for the use of alkaline water electrolysis (AWE). The solution of poly(2,2’-(1,4-naphthalene)-5,5′-benzimidazole) (NPBI) containing porogen additive in DMSO solvent was casted and then transformed into a porous membrane by using selective solvents to leaching out the low-molecular-weight additive. Compared with the pristine NPBI membrane, the introduction of porosity significantly enhanced electrolyte absorption from 70 % to 190 %, and reduced the areal resistance from 0.4 Ω cm 2 to 0.15 Ω cm 2 . Besides, the lower H 2 permeability (7.3 Barrer) and higher bubble point pressure (>10 Bar) exhibited by the KOH doped porous NPBI membrane (NPBI-75) depicted its potential to work efficiently and safely. In an alkaline water electrolysis test using a PGM-free catalyst in 6 M KOH at 80 °C, the NPBI-75 exhibited a current density of 2500 mA/cm 2 at 2.06 V, which outperformed the pristine membrane and commercial Zirfon separator. Moreover, the NPBI-75 exhibited excellent durability up to 700 h at 2000 mA/cm 2 , which is the highest current density reported so far. The excellent ionic conductivity of NPBI-75 enabled it to work at a relatively lower temperature for 700 h without voltage increase. The improved strategy based on PBI polymer proposed in this paper provided a new strategy for the development of high-performance ion-solvating membranes for AWE.
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
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2020
·Vol. 150
·期 11
·3174-3183
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IF 2.482
Wang Xun-Qiang,Li He,Yuan Qi-Yue,Liu Xiao-Qin,Liu Ding-Hua
Abstract Polycarbonate diols (PCDLs) are intermediates used in the synthesis of polyurethanes (PU), and therefore their efficient and green synthesis is a necessity. In this work, KOH/K 2 CO 3 @ γ -Al 2 O 3 catalysts were prepared and employed in the synthesis of PCDLs. A 4 wt% KOH/40 wt% K 2 CO 3 @ γ -Al 2 O 3 catalyst and a DMC: 1,4-BDO molar ratio of 1.25:1 exhibited the best activity for the reaction and gave a PCDL yield of 95% with a molecular weight of 4527 g·mol −1 . Moreover, the catalyst could be reused 4 times without a significant loss of the catalytic activity in transesterification. The effects of the catalyst composition and reaction conditions on the synthesis of PCDLs were investigated. The results indicate that the catalyst amount and the molar ratio of DMC: 1,4-BDO can influence the purity of PCDLs. Graphic Abstract The reaction equation
Catalyst preparation
The synthesis of PCDLs using DMC and 1,4-BDO
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
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2014
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IF 1.178
Yong Xiao,Chao Long,Ming-Tao Zheng,Han-Wu Dong,Bing-Fu Lei,Hao-Ran Zhang,Ying-Liang Liu
High-performance supercapacitor electrode materials are prepared from the commercially available activated carbon (AC) through a facile and low-cost chemical activation method. The obtained results show that AC activated by KOH with an alkali/carbon ratio of 6/1 (ACK6) possesses a specific surface area of 3405 m 2 /g, a large pore volume of 2.01 cm 3 /g, and exhibits the highest initial specific capacitance of 335 F/g at the current density of 0.5 A/g in 6 mol/L KOH, and 85% coloumbic efficiency for 5000 cycles at 20 mV/s.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Jie Wang,Gang Chen,Xue Bai,Chao Chen,Zixuan Zhang,Zhengtang Su,Zhijun Zhou,Fei Chen,Yilong Ma,Wei Cai,Rongli Gao,Chunlin Fu
To further study the microwave absorbing properties of hexagonal barium ferrites (abbreviated as BaM) fabricated by using an innovative hydrothermal method with different mineralizers, the crystal structure, morphology, magnetoelectric and the microwave absorption properties of BaM were systematically studied. X-ray diffraction patterns (XRD) show that all samples exhibit a pure phase for BaM. At the same time, the grain size and morphology can be controlled and the thicker and regular hexagonal flakes were obtained using KOH mineralizer. The maximal magnetization in the field 15 kOe of BaM can be improved by using KOH mineralizer compared to NaOH mineralizer, while the coercivity ( H c ) is slightly reduced. The maximal magnetization in the field 15 kOe is 31.83 emu/g and 43.36 emu/g for BaM synthesized with NaOH and KOH mineralizers, and the H c is 860.23 Oe and 842.00 Oe, respectively. Meanwhile, the RL values of BaM synthesized with NaOH mineralizer are greater than − 3.00 dB indicating poor absorbing property. While, as for the BaM synthesized with KOH mineralizer, the electromagnetic wave absorption performance is enhanced greatly. The minimum value of the reflection loss ( RL min ) is − 17.59 dB obtained at 13.2 GHz with a thickness of 1.5 mm, and the effective absorption bandwidth is up to 3.2 GHz (11.6∼14.8 GHz) for BaM with KOH mineralizer. This work provides a kind of effective method to enhance the microwave absorption properties of BaM material by changing the mineralizer, and suggests that BaM is a microwave absorbing material with great potential engineering applications for 5 G communication.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2022
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IF 6.437
Weixi Zhang,Haodi Tan,Yingquan Chen,Haiping Yang,Hanping Chen
The pyrolysis of hydrochar from hydrothermal treatment of kitchen waste was investigated, including the process parameters and characteristics of pyrolysis products. A novel process, KOH-assisted catalytic pyrolysis , was proposed to simultaneously produce oil and char products with high quality. The optimum pyrolysis temperature was 550 ℃, at which the three-state products presented better properties. Four zeolite catalysts were investigated to improve the quality of the oil product. SAPO presented the highest promoting effect on aromatic hydrocarbons, whereas HZSM-5 promoted the selectivity of nitrogen components. Upon KOH addition, the selectivity of aromatic hydrocarbons increased from 42.2% to 98.8% for HZSM-5, whereas oxygen- and nitrogen-containing substances disappeared. In addition, the char S BET increased from 7.16 to 1753.57 m 2 /g, with specific capacitance of 206 F/g and methylene blue adsorption capacity of 317.68 mg/g. The results provide a useful background for the development of the treatment of hydrochar.
研究领域:
环境科学
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能源工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Chenyu Wang,Xiaolong Ling,Chaoyue Wu,Chao He,Biao Gui,Weibo Sun
Phosphorus is a very important resource, and dewatered cyanobacteria contains a large amount of it. Basic additives, such as KOH, are often used to promote hydrogen production during supercritical water gasification (SCWG) of biomass, but their effects phosphorus transformation have rarely been investigated. In this study, SCWG of dewatered cyanobacteria with potassium salt and KOH was conducted in autoclave at 400 °C for 10 min, to investigate the effect of K + on the transformation of phosphorus under neutral and alkaline conditions. Results showed that K + increased the proportion of phosphorus in the solid phase from 88.4% to 90.8–98.3%. Furthermore, K + could promote the transformation of iron-combined phosphorus to calcium-combined phosphorus and occluded phosphate. Only when the reaction environment was alkaline, the proportion of phosphorus in the solid phase was significantly reduced to a minimum of 26.1%. When the amount of OH − was sufficient, can this part of phosphorus and organic phosphorus , which was decomposed and transformed by the promotion of OH − , be transferred to the liquid products. Results from this study laid a foundation simultaneously for hydrogen production and phosphorus recovery more environmentally and high-effectively.
研究领域:
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Xi Zhang,Yan Xu,Yong Zhou,Yinyan Gong,Yongli Huang,Chang Q Sun
An incorporation of the hydrogen bond (O:H O or HB) cooperativity notion, contact angle detection, and the differential phonon spectrometrics (DPS) has enabled us to gain refined information on the HCl, KCl and KOH solvation resolved solute-solvent molecular interactions and the solution surface stresses. Results show that ionic polarization stiffens the solvent H O bond phonon from 3200 to 3480 cm −1 in the hydration shells. The HO − in alkaline solution, however, shares not only the same H O phonon redshift of compressed water from 3200 to < 3100 cm −1 but also the dangling bonds of H 2 O surface featured at 3610 cm −1 . Salt and alkaline solvation enhances the solution surface stress by K + and Cl − ionic polarization. The excessive H + proton in acid solution forms a H↔H anti-HB that depresses the solution surface stress, instead. The solute capability of transforming the fraction of the O:H O bonds of the solvent matrix is featured by: f H = 0 and f x ∝ 1-exp(-C/C 0 ) (x = HO − , K + and Cl − ) towards saturation. Exercises not only confirm the presence of the H↔H anti-HB point fragilization, the O:⇔:O super-HB point compression, and ionic polarization dominating the performance of the respective HCl, KOH, and KCl solutions, but also demonstrate the power of the DPS that enables high resolution of solute-solute-solvent interactions and correlation between HB relaxation and solution surface stress.
研究领域:
化学
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物理化学
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DOI
高影响因子
ChemCatChem
·
2020
·Vol. 13
·期 3
·916-923
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IF 4.853
Qianqian Xu,Xueru Sheng,Haiyuan Jia,Na Li,Jian Zhang,Haiqiang Shi,Meihong Niu,Qingwei Ping
Graphical A heterogeneous catalyst (KOH/diatomite) was prepared in a simple way, and exhibited good activity (overall yield: 85.0 %). We suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond, the impurity elements existed in diatomite and higher BET surface areas may also benefit. Aldol condensation of cyclopentanone is an attractive reaction for bio-jet fuel production. KOH is an efficient homogeneous catalyst for aldol condensation but suffering the problem of separation. In this paper, a heterogeneous catalyst, diatomite stabilized KOH (KOH/diatomite) was prepared in a simple way (dry-mixed impregnation process), and exhibited good activity (overall yield: 85.0 %) and reusability. To clarify the support effect of diatomite, KOH/SiO 2 catalyst was also prepared. According to characterizations of these two catalysts, we suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond. In addition, the impurity elements existed in diatomite (e. g. CaO, Na 2 O, Al 2 O 3 ) and higher BET surface areas may also benefit to this reaction. This study provides a new possibility for converting homogeneous catalyst (KOH) to heterogeneous catalyst (KOH/diatomite). In this way, KOH/diatomite performed excellent catalytic activity and exhibited stable reusability, which can avoid the problem of separation and pollution.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2012
·
IF 2.947
Xing Li,Jijuan Su,Honghong Chang,Gong Li,Yanwei Li,Wenlong Wei
A simple and efficient method has been developed which describes KOH-oriented catalytic regioselective ring-opening reactions of various N -tosylaziridines with malonates. In the presence of 20 mol% KOH, most N -tosylaziridines can smoothly react with malonates to give the corresponding products in good to excellent yields (up to 99%) and with good to excellent regioselectivity under mild experimental conditions.
研究领域:
有机化学
·
合成化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Jian Tian,Lu Wang,Lixue Qi,Qun Li,Daohua Sun,Qingbiao Li
As an abundant and renewable biological resource, straw has been attracting wide attention due to its distinctive tubular structure and property. Herein, soybean straw was pretreated by KOH and was used as a support for Pt nanoparticles (NPs) to realize efficient benzene combustion. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of straw-derived samples illustrated the channel wall with open macropores and uniform distribution of Pt NPs in the straw skeleton. As a result, the temperature for 90% benzene conversion (T90%) by Pt/KAC-3 (Pt/KAC-n, where n represents the mass ratio of straw to KOH that was varied between 1:1, 1:2, and 1:3) was determined to be 179 °C under a space velocity (SV) of 120 000 mL/(g·h). Additionally, thermal stability was enhanced to nearly 96 h. This performance is predominantly attributed to its inherent channel structure, which has open and accessible pores, resulting in a uniform distribution of Pt NPs. Such structure enables the rapid transfer of benzene molecules between channels and ensures the accessibility of Pt NPs. Furthermore, the diffusion properties were confirmed by Fick’s second law. This study demonstrated a design of more efficient catalysts while using a renewable and abundant biomaterial.
研究领域:
环境科学
·
材料科学
✓ 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）