PHYSICA B-CONDENSED MATTER
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2023
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IF 2.8
Wang Bo-Hao,Dan Zhao,Zhang Rui-Juan,Yao Qing-Xia,Jia Lei
Developing new phosphors is an important issue for white LED applications. Herein, a simple compound NaAlO 2 with an unusual compact 5-coordinated [NaO 5 ] polyhedral environment is selected as host material. After doping Bi 3+ into NaAlO 2 , Bi 3+ may be occupy the Na-sites and interesting luminescent properties are expected. Experimental results show that phosphor NaAlO 2 :Bi 3+ can emit cyan light under near-UV excitation. More exciting, the luminescent intensity of NaAlO 2 is rather stable under high temperatures, which is due to the good structural rigidity of NaAlO 2 host lattice and the process of trap-to-activator energy transfer. At 450 K, the typical working condition of LED devices, the PL intensity constitutes 92 % of the intensity at 300 K, which can guarantee its luminous efficiency for applications in LED devices. Finally, a white LED was fabricated by using a 365 nm LED ship, and a mixture of CaAlSiN 3 :Eu 2+ (red phosphor), BaMgAl 10 O 17 :Eu 2+ (blue phosphor) and NaAlO 2 :0.007Bi 3+ . The CIE coordinates, rendering index (Ra) and Correlated Color Temperature (CCT) of this lamp are (0.3183, 0.3307), 96.8 and 4429 K. This work confirms that the NaAlO 2 :Bi 3+ material is a promising cyan phosphor for applications in LED field.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
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2019
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IF 7.181
Yujiao Zhang,Shengli Niu,Chunmei Lu,Zhiqiang Gong,Xun Hu
This research focused on the novel, low-cost and green NaAlO 2 /γ-Al 2 O 3 heterogeneous nanocatalyst, which exhibited the excellent performance in catalyzing transesterification of palm oil with methanol for the biodiesel production. The physicochemical properties of the catalysts were characterized by different methods of the X-ray diffraction (XRD), N 2 adsorption–desorption, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Hammett indicators, field emission scanning electron microscopy-energy dispersive spectrometer (FESEM-EDS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). The transesterification parameters, such as the methanol to oil molar ratio, catalyst content and reaction temperature, were optimized using the central composite design (CCD) based the response surface methodology (RSM), where the maximum biodiesel yield of 97.65% was achieved at the methanol to oil molar ratio of 20.79:1, catalyst content of 10.89 wt% and reaction temperature of 64.72 °C. The biodiesel yield was dropped to 52.16% for the third reused cycle due to the leaching of the active sites into the liquid phase. However, the spent catalyst could be effectively regenerated with a small number of active sites and the regenerated catalyst maintained the biodiesel yield of 93.29% for the sixth reused cycle. The properties of the produced biodiesel were in accordance with the ASTM D 6751 standard. Also, the biodiesel production process was environmental friendly based on the green chemistry metrics.
研究领域:
化学工程
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可再生能源
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催化科学
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DOI
高影响因子
RSC Advances
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2019
·Vol. 9
·期 18
·10072-10080
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IF 3.049
Xin Niu,Liguo Wang,Junya Cao,Yan Cao,Peng He,Junya Zhou,Huiquan Li
A novel approach for the synthesis of epoxybutane via decarboxylation of butenyl carbonate derived from butanediol was developed for the first time. For the carbonylation of butanediol with dimethyl carbonate, NaAlO2 has exhibited excellent catalytic activity under mild reaction conditions. The yield of butenyl carbonate reached as high as 96.2%. NaAlO2 provides suitable acid–base active sites to promote the transesterification reaction of butanediol and dimethyl carbonate. For the following step of decarboxylation of butenyl carbonate, ionic liquid 1-butyl-3-methylimidazolium bromide could effectively catalyze the decarboxylation process both in batch or continuous processes. Moreover, the catalytic mechanism for the crucial step of decarboxylation of butenyl carbonate over 1-butyl-3-methylimidazolium bromide was explored using DFT calculations. The results showed that the electrostatic and hydrogen-bond effects of 1-butyl-3-methylimidazolium bromide played a crucial role for the generation of epoxybutane. Briefly, the Br anion of the ionic liquid attacks the methylene of the ring and the H of the ionic liquid cation attacks the carbonyl oxygen, which facilitated the five-ring opening and subsequent decarboxylation to form BO. This study not only provided a new and green synthetic route for producing epoxybutane, but also contributed to the effective utilization of butanediol, which is inevitably produced as by-product in the process of coal to ethylene glycol, suggesting a promising application in the clean manufacture of epoxybutane with inexpensive cost.
研究领域:
化学工程
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绿色化学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Zhichao Yang,Weiquan Cai,Jinpeng Zhou,Qing Xia,Tielin Wang
A fast, large-scale, and stable preparation method was successfully developed to obtain η-Al2O3 microspheres with particle sizes of 3–10 μm from cheap and widely sourced NaAlO2 solution using N,N-dimethylformamide (DMF) as a morphological modifier and a precipitant simultaneously at room temperature. The yield of alumina increases from 33.3 to 77.3% by increasing the dose of DMF from 100 to 400 mL. The utilization efficiency of DMF significantly increased by adding fresh NaAlO2 into the reused filtrate after separating the bayerite precipitate (precursor of η-Al2O3). Importantly, the η-Al2O3 microspheres obtained from the filtrate-reuse experiments show the stable phase structures, morphologies, and pore structure properties. Furthermore, the typical η-Al2O3 microspheres supported Pd catalyst presents a higher catalytic activity of 10.6 g/L for the hydrogenation of anthraquinone than that of the commercial γ-Al2O3-supported Pd catalyst (8.5 g/L), suggesting that the as-prepared η-Al2O3 microspheres have good application prospects for catalytic hydrogenation and related fields.
研究领域:
材料科学
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催化
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Pengfei Zhao,Jian Gong,Zepeng Yang,Ke Wang,You Ding,Jie Chen,Edward J. Anthony
The utilization of integrated CO 2 capture and utilization methods to produce value-added fuels and chemicals represents a promising approach in addressing the global warming crisis. Nonetheless, the development of cost-effective, efficient, selective, and stable dual-functional materials still poses a significant challenge. Our conversion tests and structural characterizations reveal that coupling Ca-looping (CaL) with the reverse-Boudouard (RB) reaction using a blend of limestone, NaAlO 2 , and biochar can achieve efficient capture and in situ conversion of CO 2 . In comparison to traditional alkali-carbonate catalysts, the aluminum oxide served as a passivator, impeding the acceleration of CaCO 3 decomposition, enhancing in situ CO yield, preventing catalytic deactivation from Na component reacting with ash components, and alleviating CaO sintering. This strategy enabled exceptional CO 2 conversion efficiency (approximately 90.0 %), high CO selectivity (nearing 100 %), and stability even through multiple cycles (around 90.0 %), representing a 20 % improvement over our prior materials (limestone mixed with K 2 CO 3 -impregnated biochar). Notably, density functional theory calculations further demonstrate that the activation energy barriers for monatomic C-assisted CO 2 dissociation were lower than the desorption energy of CO 2 on the NaAlO 2 (101) surface, indicating that most of the released CO 2 from limestone can subsequently be converted into CO on the NaAlO 2 surface. Hence, this cost-effective passivation approach offers a scalable solution for closing the carbon cycle from large stationary sources without necessitating carbon sequestration.
研究领域:
能源与燃料
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环境科学
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化学工程
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材料科学
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催化
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
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2021
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IF 8.001
Yilin Ning,Shengli Niu,Yongzheng Wang,Jianli Zhao,Chunmei Lu
This work reported the one-pot synthesis of the promising, cheap and green heterogeneous nanocatalyst for biodiesel production . The halloysite nanotube (HNT) was impregnated with 40 wt % NaAlO 2 (SA) and the assistance of ultrasonic helped to achieve a better and more stable modification. The resulting 0.4SA/HNTs-UI catalyst was applied in catalyzing the transesterification of palm oil with methanol, using a GA_BP neural network to train and predict the optimal values of reaction parameters. The test results proved the prediction accuracy of the model with R 2 = 0.989. The catalyst possessed excellent performance, and the maximum biodiesel yield of 99.15% was achieved with the catalyst loaded amount of 8.82 wt %, methanol to oil molar ratio of 16.79 and transesterification temperature of 65.12 °C. Besides, the physicochemical properties of the purified transesterification product were in accordance with the ASTM D 6751 standard of biodiesel .
研究领域:
能源化学
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催化材料科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2019
·Vol. 46
·期 6
·7625-7633
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IF 3.45
Yulin He,Ying Li,Nianchun Yao,Jiamei Li,Wenxian Li,Ziqiang Wang
A long-lived cycling property is an important factor for the extensive use of the lithium-ion batteries. In this study, a NaAlO 2 layer was initially coated on the LiNi 0.5 Co 0.2 Mn 0.3 O 2 surface. Electrochemical tests indicate that the coated surface achieves better cycling stability and a higher capacity at 25 °C. In addition, the 1 wt % NaAlO 2 -coated sample exhibits the best performance, and it also exhibits a discharge specific capacity of 189.6 mAh∙g −1 at 0.1C in the first cycle. After 800 cycles at 1C, the capacity retention of the 1 wt % NaAlO 2 -coated sample is approximately 73.31%, a value that is 21.26% higher than the pristine sample. The electrochemical impedance spectroscopy (EIS) analysis reveals a decrease in the LiNi 0.5 Co 0.2 Mn 0.3 O 2 charge transfer impedance and a significant increase in lithium ion diffusion after the application of the NaAlO 2 coating. The high ion diffusion coefficient and low charge transfer impedance are conducive to the better rate performance of NaAlO 2 -coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 .
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DOI
高影响因子
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