RSC Advances
·
2023
·Vol. 13
·期 36
·24944-24954
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IF 3.9
Lin Li,Tao Zeng,Hongyu Huang,Jun Li,Noriyuki Kobayshi,Xiaohu Yang
In this study, the influences of nano γ-Al2O3 on the thermal storage performance of LiCl were experimentally investigated. The XRD results show that a complex of lithium aluminium oxychloride (LiAlOCl2) was formed through the LiCl·H2O and γ-Al2O3 composites preparation process. The in situ diffuse reflectance infrared Fourier transform spectroscopy measurement reveals that the addition of γ-Al2O3 accelerated the hydration rate of LiCl composites, concentrated the spectrum utilization range, and promoted the desorption rate of physical adsorbed H2O and low-frequency structural –OH in the materials. The highest specific surface area of the composite is 34.5 times higher than that of pure LiCl. The addition of γ-Al2O3 can increase the conversion rate of LiCl·H2O to approximately 100% at the hydration time of 1 h and the addition content of γ-Al2O3 at 15 wt%. A maximum heat storage density (HSD) for the LiCl·H2O-γ-Al2O3 composite can reach 714.7 kJ kgLiCl·H2O−1 in 1 h when the addition content of γ-Al2O3 was 15%wt and its water uptake can reach 0.26 g g−1 in 1 h. It also can be found that the addition of Al2O3 in LiCl resulted in a decrease of the activation energy from 90.89 kJ mol−1 to 79.76 kJ mol−1. However, the thermal conductivity of the LiCl·H2O-γ-Al2O3 composite slightly decreased with the increase of nano γ-Al2O3 content.
研究领域:
材料科学
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能源存储
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化学工程
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产品关联
DOI
PubMed
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 8
·期 4
·778-783
·
IF 5.2
Huan Liu,Yi-Xuan Yao,Hong-Yan Shang,Da Yang,Yuan-Yu Tian
The tandem hydroformylation–acetalization of olefins with H2O as the hydrogen source was accomplished over an Ir(I)-catalyst using the phased warming strategy. Due to the release of protons by AlCl3-hydrolysis equilibrium, the tandem reaction was significantly enhanced. The conversion of 1-hexene was 100% and the selectivity for oxo-products was 89%, where 91% of acetals was obtained. Moreover, the hydrogenation by-products were detected to be less than 3%, showing that H2O as the hydrogen source inhibited the hydrogenation of olefins in this tandem reaction. Moreover, isotope-labeling experiments confirmed that water was the hydrogen source, and the key Ir–H active species for hydroformylation were captured by high-pressure 1H NMR spectroscopy analyses.
研究领域:
化学催化
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有机合成
✓ 已验证
产品关联
DOI
高影响因子
FARADAY DISCUSSIONS
·
2016
·Vol. 190
·219-230
·
IF 3.544
Yong-Qi Li,Huan Liu,Peng Wang,Da Yang,Xiao-Li Zhao,Ye Liu
A highly efficient and stable Rh–P catalytic system in the RTIL of [PEmim]BF4 was developed for the biphasic hydroformylation of 1-octene by using the diphosphine-functionalized ionic liquid (FIL) of 2. While 2-Rh(acac)(CO)2 was immobilized in [PEmim]BF4 (solvent), a typical biphasic catalysis was fulfilled with advantages of facile separation and recycling ability – 9 runs without any loss of activity. It was found that not only the acquired π-acceptor character of 2, but also the synergetic role of the piperidyl group in [PEmim]BF4 as an N-containing donor, cooperatively contributed to the efficient hydroformylation due to the facilitated formation and stability of the Rh-H active species (ν 2045 cm−1). This was supported by the in situ high-pressure FT-IR spectral analysis.
研究领域:
化学工程
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催化科学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·
IF 4.914
Zhi-Hua Zhou,Xiao Zhang,Yong-Fu Huang,Kai-Hong Chen,Liang-Nian He
Inexpensive and efficient Cu(I) catalysis is reported for the synthesis of α-hydroxy ketones from propargylic alcohols, CO 2 , and water via tandem carboxylative cyclization and nucleophilic addition reaction. Notably, hydration of propargylic alcohols can be carried out smoothly under atmospheric CO 2 pressure, generating a series of α-hydroxy ketones efficiently and selectively. This strategy shows great potential for the preparation of valuable α-hydroxy ketones by using CO 2 as a crucial cocatalyst under mild conditions.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 16
·8887-8897
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IF 14.511
Donglin Han,Peng Zhong,Xiaorong Zhang,Lulu Jiang
Electrolytes with excellent chemical stability and high proton conductivity are key materials for protonic ceramic fuel cells and electrolyzers. Doping aliovalent cations to increase the number of oxygen vacancies is a common method to increase conductivity. However, determining proper sites for efficient doping is a matter of general concern because in many cases, there are several cation sites in complex oxides. In this work, we used EXAFS analysis to probe the changes in the local structure of proton-conducting pyrochlore oxides, La2(Nb0.4Y0.6)2O7−δ (LNY60) and La2(Nb0.35Y0.65)2O7−δ (LNY65), upon hydration and found that the coordination number of the oxygen sites in the vicinity of La and Y increased after hydration, indicating that these oxygen sites were active for the hydration reaction to introduce protons. Thereafter, the trivalent La sites were doped with divalent Ca, Sr and Ba cations to introduce more oxygen vacancies into the adjacent oxygen sites to facilitate the hydration reaction. As expected, the proton conductivity increased with increasing content of Ca, Sr and Ba. The conductivities of 2.54 at% Ca-doped LNY60 and 0.98 at% Sr-doped LNY65 were both 1.16 × 10−3 S cm−1 at 700 °C, nearly four times higher than those of the pristine oxides. These results indicate that assisted by EXAFS analysis, proper dopant sites can be determined precisely to further elevate proton conductivity in oxides.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2024
·Vol. 27
·期 32
·e202400241
·
IF 2.2
Donglin Jiang,Yuchen Zhou,Mengfan Du,Zezhi Chen,Huijuan Gong
Graphical The modification of ZIF-8 with dopamine results in a large amount of hydrophilic and CO 2 friendly groups introducing into the ZIF-8 molecules, and the structure and specific surface area of ZIF-8 is also improved. These factors lead to an improvement performance of ZIF-8 in the catalytic CO 2 absorption in water and alkaline solutions. CO 2 capture technology has been widely used to reduce CO 2 emissions, resulting in a variety of capture methods and materials. Among them, the more widely used is the chemical absorption method. However, the chemical absorption method has problems such as high energy consumption and slow absorption rate. In order to solve the above problems, we prepared an effective catalyst to improve the CO 2 absorption rate. ZIF-8 and hydrophilic ZIF-8-DA were prepared by in situ synthesis under ambient conditions. The catalytic effect of the hydration reaction of ZIF-8 and ZIF-8-DA was tested using CO 2 absorption regeneration experiments under aqueous and alkaline conditions, respectively. The results showed that the synthesized catalysts could significantly enhance the CO 2 absorption in water and alkaline solution. The addition of 0.1 wt % of ZIF-8 in alkaline solution increased the average CO 2 absorption by 1.80–15.84 %, respectively, while the addition of 0.1 wt % of ZIF-8-DA increased the CO 2 absorption by 7.01–25.36 %. In addition, both catalysts had excellent reusability and maintained high performance even after five absorption and regeneration cycles. Polymer dispersibility index (PDI) results showed that ZIF-8-DA dispersed more uniformly in aqueous solution.
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
CHEMICAL PAPERS
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2020
·Vol. 74
·期 11
·3987-3993
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IF 1.68
Pan Binfeng,Zhang Zhimin,Lu Xuchen
Abstract The reaction between rare earth oxychloride (REOCl) and water was investigated. X-ray diffractometer, volumetric titrations, FTIR spectrograph and scanning electron microscope were used to determine the reaction process and the reaction products. It was found that the reaction could be concluded as follows: 5REOCl(s) + 5H 2 O(l) = 2RE 2 (OH) 5 Cl(s) + RE 3+ (aq) + 3Cl − (aq). Based on this reaction, a new method for determining the purity of anhydrous rare earth chloride was proposed. Compared with the conventional method, the maximum absolute error decreased from 22 to < 1% and the maximum relative error decreased from 111 to < 4% under the experimental conditions. Graphic abstract
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Wen Xu,Xiaoshu Wang,Weilong Hou,Kang Tang,Xinqing Lu,Yijing Gao,Rui Ma,Yanghe Fu,Weidong Zhu
Although the titanosilicate zeolite catalyzed one-pot oxidative hydration of ethylene with hydrogen peroxide (H 2 O 2 ) to ethylene glycol (EG) takes advantages of step-saving and facile operation, both H 2 O 2 utilization efficiency and EG yield are relatively low. In the present work, Sn-doped Ti-MWW zeolites, named Sn-Ti-MWW, were developed for this oxidative hydration, showing the much higher H 2 O 2 utilization efficiency and EG yield, compared to Ti-MWW. The extensive characterizations of Sn-Ti-MWW zeolites, in combination with Density Functional Theory (DFT) calculations, verify that the doping of Sn into Ti-MWW leads to the higher electropositivity of the Ti species, resulting in the stronger acidity of the zeolite, which is helpful to the H 2 O 2 utilization and EG production. In addition, although the catalyst deactivation is observed due to the deposition of the bulky byproducts onto the active sites and/or into the zeolite micropores, the simple calcination of the used catalyst readily restores its catalytic activity. Therefore, it is anticipated that the developed Sn-Ti-MWW catalyst might be applicable in the one-pot oxidative hydration of ethylene with H 2 O 2 to EG industrially.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
Journal of Energy Storage
·
2022
·
IF 8.907
Zhiguo Bian,Yingjie Li,Feifei Wang,Yi Fang,Jianli Zhao,Jianhui Qi
CaO/Ca(OH) 2 heat storage system is one of the most promising candidates for large-scale thermochemical heat storage at temperature of 300–600 °C. In this work, the CaO/Ca(OH) 2 heat storage performances of the Ce- and Mn-doped CaO were investigated and the mechanisms of promoting hydration by Ce and Mn doping were determined via density functional theory (DFT) calculations. The Mn-doped CaO exhibits the higher hydration conversion than CaO and Ce-doped CaO. The structural parameters, partial density of states, electron differential densities and energy barriers during hydration stage on the CaO, Ce- and Mn-doped CaO surfaces were compared to clarify the effects of Ce and Mn on hydration of CaO. The results show the detailed hydration reaction pathways on the CaO, Ce- and Mn-doped CaO surfaces. During the H 2 O adsorption stage, H 2 O on the Ce-doped CaO surface approaches the Ca atom first, while H 2 O on the Mn-doped CaO surface approaches the O s atom first. The adsorption energy for Ce- and Mn-doped CaO are −1.612 and −0.896 eV, respectively, which are higher than that for CaO. The doping of Ce and Mn accelerates the H 2 O adsorption on the CaO surface. The Mn doping causes the 84.3 % reduction in the energy barrier for hydration of CaO and the reduction by Mn doping is larger than that by Ce doping. Thus, Mn-doped CaO exhibits the higher hydration reactivity and hydration conversion than CaO and Ce-doped CaO. The DFT calculations determined the promotion mechanism of Ce and Mn doping on the hydration of CaO in CaO/Ca(OH) 2 heat storage.
研究领域:
材料科学
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热能储存
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计算化学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 4
·942
·
IF 3.1
Hao Zhang,Zhaozhou Wei,Deyuan Xiong,Yao Wu,Menglong Tong,Huiping Su,Zuoyuan Zhang,Jian Liao
Using sodium lignosulfonate as feedstock, ZnCl2and NaHCO3co-activated the hierarchical porous carbons (HPCs) were prepared by one-pot pyrolysis with different NaHCO3dosages (0–4 g) and carbonization temperatures (400–600 °C). Subsequently, phosphotungstate (HPW) was supported with the resulting biochar for the α-pinene hydration reaction to produce α-terpineol. The optimum preparation conditions were determined according to the yield of α-terpineol. The formation mechanism and physicochemical properties of HPCs were analyzed through TG, SEM, XPS, XRD, FT-IR, and N2adsorption–desorption isotherms. The results demonstrated that NaHCO3underwent a two-step reaction which liberated a substantial quantity of CO2, thereby enhancing activated carbon’s macroporous and mesoporous structures. Simultaneously, NaHCO3mitigated strong acid gas (HCl) emissions during ZnCl2activation. Compared with AC450-4:8:0 prepared by ZnCl2activation alone, the total pore volume of AC450-4:8:2 prepared by co-activation is increased from 0.595 mL/g to 0.754 mL/g and the mesopore rate from 47.7% to 77.8%, which is conducive to reducing the steric hindrance of the hydration reaction and improving the selectivity. Hydration experiments show that the selectivity of α-terpineol is 55.7% under HPW/AC450-4:8:2 catalysis, higher than 31.0% for HPW and 47.4% for HPW/AC450-4:8:0.
研究领域:
材料科学
·
催化化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Yuchen Zhou,Yu Wang,Zezhi Chen,Huijuan Gong,Lu Chen,Huiqiang Yu
Carbonic anhydrase (CA) is an enzyme with unparallele d catalytic activity in CO2 hydration. However, its high cost and low stability seriously restrict its industrial application in CO2 absorption. Constructing CA mimics is a promising strategy to overcome the above limitations. However, to date, a majority of mimics reported are suffering from laborious synthetic processes, harsh synthetic conditions, and costly ligand materials. Therefore, developing novel CA mimics with higher applicability remains a high priority. Due to the structural similarity between zeolite imidazolate framework (ZIF)-8 and natural carbonic anhydrase (CA), ZIF-8 may be considered as a potential CA-mimetic catalyst for CO2 absorption. To validate this assumption, ZIF-8 and hydrophilic ZIF-8-TA were synthesized and the results from subsequent CO2 absorption experiments indicated that the synthesized catalysts could significantly enhance CO2 absorption in water and common alkaline solutions. The addition of 1.0 wt % ZIF-8 in water and different alkaline solutions respectively increased the average CO2 absorption rate by 42.35 and 6.78–24.51%, while the addition of 1.0 wt % of ZIF-8-TA increased the CO2 absorption rate by 81.80 and 18.16–34.39%, respectively. Besides, both catalysts possessed excellent reusability that they retained high performance even after five cycles of absorption and regeneration. Through esterase experiments, it was confirmed that ZIF-8 and ZIF-8-TA exhibited higher CA-mimetic activity than many reported CA mimics. Through density functional theory (DFT) calculations, it was indicated that the catalytic CO2 hydration pathway of ZIF-8 primarily involves four steps, including nucleophilic attack, rearrangement, replacement, and deprotonation, which is similar to that of natural CA, while ZIF-8-TA does not undergo the rearrangement step. Moreover, the electron-donation effect and van der Waals interaction of tannic acid endow ZIF-8-TA with higher catalytic activity.
研究领域:
材料科学
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环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2025
·
IF 9.4
Yufan Chen,Zexiang Li,Chunhuan Luo,Jianhao Li,Changchang Yang,Yufan Yang,Chunting Zhou,Muran He
In the context of large-scale utilization of renewable energy, the use of hydrated salts in thermochemical energy storage is seen as a critical solution to address the unpredictability and inconsistency of energy systems. Potassium carbonate was selected as the storage material due to its high energy density, safety, stability, and cost-effectiveness. A novel tubular carbon-based composite for potassium carbonate storage was developed using a centrifugal method, with carbon fiber (CF) chosen for its excellent thermal conductivity and microstructure, and perforated copper tube used for structural support. Five K 2 CO 3 -CF composites with CF contents of 6.7 %, 12.5 %, 17.6 %, 22.2 %, and 26.3 % by weight were fabricated. The CF 22.2 PC composite exhibited superior hydration performance, with an activation energy of 67.58 kJ/mol and a pre-exponential factor of 1.6132 × 10 8 s −1 for the hydrated reaction. Based on the characterization results, it is calculated that the porosity is 0.301, the theoretical thermal conductivity is 0.42 W/(m∙K), and the energy storage density in the anhydrous state is 516.90 kJ/kg. Simulations showed that high heat transfer fluid velocity, steam inlet pressure, and thermal conductivity positively influenced reaction rates, temperature increase, and power output. These findings suggest that this composite has significant potential to enhance the sustainability and reliability of energy systems.
研究领域:
能源材料
·
化学工程
✓ 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）