ADVANCED POWDER TECHNOLOGY
·
2024
·
IF 4.2
Zigui Luo,Qi Jin,Rui Wang,Zhenjia Yang,Zhaoyang Wu,Guangqiang Li,Xi’an Fan
FeSiAl/(Al 2 O 3 -Ni) soft magnetic composites (SMCs) were prepared by sintering FeSiAl/NiO composite powders, and the formation mechanism of the Al 2 O 3 -Ni composite coating and performance of the FeSiAl SMCs with different NiO coating content were studied. During sintering, high temperature promoted a reaction between Al and NiO at the FeSiAl/NiO interface, resulting in the in-situ formation of a composite coating comprising Al 2 O 3 coating with high integrity and ferromagnetic Ni coating. The interdiffusion of Al and O 2– toward the interface ensured the continuation of the reaction and growth of the composite coating. The composite coating thickened with the increasing NiO coating content, thus showing reduced real part of permeability. Saturation magnetization considerably increased until the NiO coating content exceeded 12.5 wt% owing to residual NiO. Excessive NiO coating content led to the generation of a large amount of Ni, which was not conducive to the integrity of the Al 2 O 3 coating and increased magnetic loss. The FeSiAl SMCs with 5.0 wt% NiO coating content exhibited exceptional performance with high saturation magnetization (135.3 emu/g), good frequency stability of permeability, and low magnetic loss (63.7 W/kg at 0.05 T/20 kHz).
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DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xianjie Li,Bingxiao Feng,Hailin Zhang,Yaping Liu,Meng Xiao,Tingting Huang,Quanhong Zhu,Hongbing Song
Furfural, a key biomass-derived compound, can be transformed into high-value chemicals, including methyl furoate, through oxidative esterification. This process finds broad applications across various industries. In the current study, gold nanoparticles were deposited on γ-Al 2 O 3 pretreated with NaOH etching, utilizing the urea deposit-precipitation method followed by reduction in a hydrogen atmosphere. This approach resulted in a highly active Au catalyst, which was thoroughly characterized using multiple analytical techniques. The optimization of NaOH etching enhanced the pore structure and improved the dispersion of the active metal on the support. Notably, the Au/γ-Al 2 O 3 -2 catalyst, prepared with a 2-hour etching duration using 1 M NaOH, exhibited uniformly dispersed gold nanoparticles with an average size of 2.8 nm. The smaller particle size and enhanced dispersion of these Au nanoparticles significantly contributed to the catalyst’s superior catalytic activity and recyclability. Under optimized reaction conditions, the Au/γ-Al 2 O 3 -2 catalyst achieved nearly complete conversion of 1 mmol of furfural to methyl furoate within 4 h, with both conversion and selectivity exceeding 99 %. The study also proposed a mechanism for the oxidative esterification of furfural to methyl furoate catalyzed by Au/γ-Al 2 O 3 -2. Additionally, the catalyst’s effectiveness in the oxidative esterification of various substrates was investigated, demonstrating its robust activity for aromatic aldehydes and alcohols. This broadens the potential applications of the catalyst in the synthesis of diverse valuable esters.
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高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Meng Zhang,Daliang Xu,Yanrui Wang,Jiaxuan Yang,Xiaobin Ma,Junwen Ding,Peijie Li,Langming Bai,Heng Liang
Ceramic membrane technology is effective for oil emulsion separation, while its low permeance and fouling issue yield high energy consumption in practical applications. Herein, a series of ceramic membranes were fabricated by incorporating the SiO 2 sintering aid into Al 2 O 3 ceramic powder using a compression molding method. Due to the melting and recrystallizing of SiO 2 on the surface of coarse grains, the modified ceramic membrane exhibited the underwater superoleophobicity property. After optimizing the fabrication conditions, including sintering temperature, molar ratio of Al 2 O 3 /SiO 2 and molding pressure, the modified ceramic membrane had a pure water permeance of 1319 L·m −2 ·h −1 ·bar −1 and a petroleum ether rejection rate of 97.1 %. In addition, the increase in the square quartz phase narrowed the pore size and improved the hydrophilicity of the ceramic membrane, thereby alleviating the pore blocking and enhancing the flux recovery. The flux recovery rate was about 86.1 % after the sodium hydroxide backwashing. This study presents a rational strategy for developing ceramic membranes with scalable potential for efficient oil emulsion separation.
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Bo Wang,Ziyan Zhao,Zihao Pan,Xuejian Liu,Zhengren Huang,Yan Liu
The ZnO–Al 2 O 3 –B 2 O 3 –SiO 2 (ZABS) glass powder was designed and innovatively employed to join AlN ceramics. The crystallization, thermal expansion and wettability behavior of the ZABS glass and glass-ceramic were investigated. The results shows that Zn 3 B 2 O 6 , ZnSiO 4 and Zn 4 B 6 O 13 were precipitated after heat treatments at different temperature, respectively, resulting in a variation in the coefficient of thermal expansion (CTE) of the ZABS glass ceramic. Then guided by the wetting behavior on the AlN ceramic substrate, the joining of the AlN ceramics by ZABS glass at various temperatures and holding times were conducted. Notably, Zn 3 B 2 O 6 was identified to be the primary product in the joints bonded at temperature of 700–800 °C due to the crystallization within the glass and no discernible reaction was observed between the substrate and the interlayer, while ZnSiO 4 was observed at the periphery of Zn 3 B 2 O 6 after 750 °C. Moreover, the crystalline phase Zn 3 B 2 O 6 gradually grew with the temperature and holding time increasing as the glassy phase gradually diminished, resulting in a reduction of the strength and reliability of the joints. The optimal flexural strength of the joints was 156 ± 11MPa at 700 °C for 30min. The reason for the high strength can be attributed to the interactions between the glass precipitated crystalline phase interlocking each other and the glass phase tightly bonded with the crystalline phase.
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高影响因子
FUEL
·
2024
·
IF 6.7
Shaoliang Zhu,Bingtao Zhao,Yaxin Su
High-efficiency and cost-effective adsorbents are crucial to dry capture of carbon dioxide (CO 2 ). The polyethyleneimine (PEI) was co-impregnated with tetraethylenepentamine (TEPA) on γ-alumina (Al 2 O 3 ) to synthesize the adsorbent and enhance the capture process. The influence of amine loading and operating parameters on CO 2 adsorption was investigated, and the process parameters were modeled. The results depict that the optimal loading is 50 % when functionalized either PEI or TEPA individually, which is 3.7 and 4.6 times higher than γ–Al 2 O 3 . The CO 2 capacity of γ–Al 2 O 3 functionalized with multiple amines (30 %PEI+20 %TEPA) is 2.65 mmol/g, due to the synergies of the two amines to increase the chance of CO 2 binding to the sites. Regeneration performance illustrates that the adsorbent remains at 90.2 % of the initial capacity after seven tests. The maximal capacity of 2.70 mmol/g occurs at 70 °C. Modeling results indicate the kinetics can be evaluated by the Avrami model (R 2 > 0.990) with the activation energy of 5.65 kJ/mol. The process is controlled by physical–chemical adsorption, influenced by intraparticle diffusion, as described by the deactivation model. Finally, a comparison and assessment were conducted for their techno-economic performances, and the pathway to applications was also proposed in engineering practice.
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高影响因子
Journal of CO2 Utilization
·
2024
·
IF 7.2
Luqman Abdullahi Sani,Haolong Bai,Zifu Xu,Liangliang Fu,Yining Sun,Xiaorui Huang,He Gao,Xuejing Liu,Dingrong Bai,Zhanguo Zhang,Fabing Su,Jiao Liu,Guangwen Xu
Ni/Al 2 O 3 catalysts (noted as Ni/Al-350, Ni/Al-500, and Ni/Al-700, respectively) were synthesized by a facile solution combustion method but at different combustion temperatures (350 °C, 500 °C, and 700 °C, respectively). For comparison, Ni/Al 2 O 3 (noted as Ni/Al-100) was also prepared by the impregnation method and applied in the methanation reaction. The Ni/Al 2 O 3 synthesized at the combustion temperature of 350 °C showed better performance than the others at higher combustion temperatures, and the activity for CO 2 methanation followed an order of Ni/Al-350 > Ni/Al-500 > Ni/Al-700 > Ni/Al-100. The increase in the combustion temperature decreased active sites for the H 2 and CO 2 adsorption, which could be associated with the reduced Ni dispersion and basic sites, thus lowering its activity and increasing its carbon deposition rate.
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高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Bowen Luo,Xiaoxin Chen,Yongxiang Guo,Riyang Shu,Chao Wang,Jianping Liu,Junyao Wang,Zhipeng Tian,Ying Chen
Hydrodeoxygenation (HDO) is a crucial technique for upgrading biomass-derived compounds, playing a significant role in the advancement of sustainable energy technologies. Under harsh reaction conditions, conventional HDO catalysts often suffer from reduced efficiency due to particle aggregation. This study presents a highly efficient Ni/Al 2 O 3 -C catalyst that mitigates this issue by stabilizing Ni metal particles and enhancing metal-support interactions. Characterization of the catalyst was carried out using XRD, TEM, and CO-TPD, which revealed that the incorporation of Al species improved metal dispersion and reduced the size of the Ni particles. Guaiacol, a phenolic compound derived from lignin, was chosen to evaluate the HDO performance under mild conditions. The optimized Ni/3Al 2 O 3 -5C catalyst achieved a guaiacol conversion of 99.9 % with a cyclohexane selectivity of 99.8 % at 210 °C. The outstanding performance is attributed to the high hydrogenation capacity of the small Ni particles and the acid sites on the carbon surface. Metal-support interactions stabilize the Ni particles, preventing leaching and deactivation. The catalyst has also exhibited comparable effectiveness in the HDO of both lignin-derived compounds and lignin-oils, confirming its adaptability across various substrates. The study demonstrates that Al 2 O 3 -C plays a crucial role in enhancing both the structural stability and catalytic efficiency of HDO catalysts, offering a promising approach for upgrading biomass-derived compounds.
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高影响因子
Processes
·
2024
·Vol. 13
·期 1
·15
·
IF 2.8
Bo Zhang,Peiyu Yao,Fei Li,Li Pan,Wuwan Xiong,Yang Zhang,Xiang Li
Hydrogen production through the catalytic pyrolysis of low-value organic solid waste offers a promising low-carbon and environmentally friendly pathway. However, the design of efficient hydrogen-producing catalysts remains a significant challenge. Herein, NiO/Al2O3as a catalyst precursor was utilized to investigate the effects of reduction temperature gradients (300–800 °C) on the distribution of three-phase products and the composition of gaseous products during the pyrolysis of waste textiles. Compared to unreduced NiO/Al2O3, increasing the reduction temperature (300–700 °C) led to a gradual decrease in liquid-phase products and a notable increase in gas-phase products, with the latter rising by 10.59% at 700 °C. Most strikingly, hydrogen gas production increased by 6.42% under the same conditions. Multi-characterization analyses, including XRD, TEM, and H2-TPR, revealed significant aggregation of highly dispersed Ni species in NiO/Al2O3at higher reduction temperatures. The emergence of XRD characteristic peaks and the (111) crystal face of metallic Ni (Ni0) became apparent at 700 °C. More importantly, the XPS test inferred that the increasement of hydrogen-rich gas production was ascribed to the appropriate Ni0/Ni2+ratio, and the highest hydrogen yield of 41.50% was achieved as the Ni0/Ni2+ratio reached about 1.57. This work not only provides an effective solution for the consumption of waste textiles, but also converts it into high value-added hydrogen-rich gas.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Haofan Jia,Liujing Yang,Hao Zhu,Yang Wang,Ying Chen,Kai Sun,Xinbao Li
In this study, a series of high-efficient catalyst, Co–Fe/Al 2 O 3 , were synthesized via the sol-gel method for low-temperature phenol steam reforming (PSR). The optimized catalyst, 15Co–2Fe/Al 2 O 3 , exhibited a remarkable phenol conversion of 95.3%, a H 2 yield of 92.1% at 450 °C, GHSV = 7500 h −1 and a steam-to-carbon (S/C) ratio of 10. Furthermore, the catalyst activity was maintained for 660 min before a gradual decline was observed. The NH 3 -TPD analysis revealed that the addition of Fe enhanced the surface acidity of the catalyst, providing more active sites for phenol adsorption and activation. This study aims to address the challenges associated with high reaction temperatures and poor catalyst stability in PSR. Various characterization techniques have been employed to investigate the reaction mechanisms of bimetallic catalysts in low-temperature PSR.
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高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Zhu-yu Li,Sheng Li,Le-ran Li,Qi Niu,Kai Li,Bin Hu,Qiang Lu
Thermochemical energy storage can overcome the drawbacks such as instantaneity, instability, and the incongruity between supply- and demand-side in the utilization of renewable energy. CaCO 3 /CaO is regarded as a promising material for thermochemical energy storage, whereas its stability still requires urgent improvement. In this paper, a new Al 2 O 3 and SiO 2 co-doped calcium-based material derived from eggshell (ES) was prepared for efficient heat storage. The physicochemical properties of synthesized materials were systematically analyzed. The regulation mechanisms of Al 2 O 3 and SiO 2 additions on the cyclic characteristics of heat storage materials were investigated by a thermogravimetric analyzer. The results displayed that ESCa-2.5Si2.5Al, prepared with a mass ratio of ES: Al 2 O 3 : SiO 2 = 95: 2.5: 2.5, demonstrated outstanding specific surface area of 14.64 m 2 /g and pore volume of 0.080 cm 3 /g, which were 2.74 and 5 times greater than those of ES-based CaO (ESCa), respectively. Meanwhile, SiO 2 and Al 2 O 3 could react with CaO to form Ca 3 Al 2 O 6 and Ca 2 SiO 4 , their synergistic effect could efficiently improve the sintering resistance of CaO. Therefore, ESCa-2.5Si2.5Al possessed excellent cyclic stability. Its initial energy storage density was 2273.19 kJ/kg, and the retention ratio reached 72.93 % after 20 cycles, significantly higher than that of ESCa (19.35 %). In addition, compared with ESCa, the heat storage temperature of ESCa-2.5Si2.5Al decreased from 792 °C to 778 °C, and its carbonation rate only slightly attenuated over 20 cycles, enabling rapid heat storage at lower temperatures and stable heat release.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 41
·25746-25752
·
IF 3.108
Li Xu,Qin Xu,Xiaoyu Guo,Ye Ying,Yiping Wu,Ying Wen,Haifeng Yang
Alumina is widely recognized as chemically inert, and resistant to oxidation and high temperature. In this study, Au/Al2O3 nanocomposites (NCs) were prepared by a facile method and were used as a surface enhanced Raman scattering (SERS) substrate for detection of adenosine triphosphate (ATP). This Au/Al2O3-based SERS substrate demonstrated good sensitivity with the lowest detectable concentration of 5 × 10−9 M for ATP and a good linear relationship ranging from 5 × 10−5 to 5 × 10−9 M. The strategy of improvement of SERS detection sensitivity for ATP was based on the consideration of ATP captured by such SERS substrate via chelation of aluminum and phosphates, which was validated by X-ray photoelectron spectroscopy. In addition, alumina as a supporting material could be expected to prolong the stability of such a SERS substrate.
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高影响因子
MOLECULES
·
2024
·Vol. 29
·期 13
·2959
·
IF 4.2
Hejingying Niu,Jinhua Ma,Lina Gan,Kezhi Li
In this study, a PtSn/Al2O3catalyst with bimetallic uniform distribution in the sphere was synthesized. The PDH performance and characterization analyses, such as with FTIR, XPS, and NH3-TPD, were investigated. The effects of acid on the PDH performance were analyzed. Citric acid (CA) acted as a competing adsorbent in the preparation process of the PtSn/Al2O3catalyst to synthesize the uniform catalyst. Water washing and alkali-treated samples were also studied. SEM line scanning revealed that increased the apparent concentration of Pt metal from 0.23 to 0.30 with citric acid. In contrast to the fresh PtSn/Al2O3catalyst, the addition of citric acid increased the PDH selectivity from 74% to 93%. After alkali or water washing treatments, the catalyst’s selectivity further increased to 96%. Strong acid sites promoted the breaking of C–C bonds during the PDH reaction, resulting in more methane and ethylene byproducts, and decreased catalyst selectivity for fresh PtSn/Al2O3. From the PDH reaction thermodynamic analysis, a relatively sub-atmospheric pressure environment with a lower propane pressure could be the reasonable choice.
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PubMed
高影响因子
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