RSC Advances
·
2015
·Vol. 5
·期 127
·104884-104890
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IF 3.84
Yuan Cai,Huihui Huang,Lei Wang,Xiaojun Zhang,Yuewei Yuan,Rui Li,Hui Wan,Guofeng Guan
Mesoporous γ-AlOOH and γ-Al2O3 with fibrous morphology were successfully synthesized by an ionic liquid ([OMim]Br) assisted low temperature precipitation method using aluminum nitrate and ammonia as aluminum source and precipitant, respectively. The samples were characterized by XRD, TG, FT-IR, TEM, and N2 adsorption–desorption technique. The results showed that the concentration of [OMim]Br had a significant effect on the phase, porous structure, and morphology of γ-Al2O3 due to the strong interactions between [OMim]Br and γ-AlOOH. High purity γ-AlOOH was synthesized at 0.2 M [OMim]Br and γ-Al2O3 with a specific surface area of 243.53 m2 g−1, pore volume of 0.68 cm3 g−1, and average pore size of 11.10 nm was obtained after calcination. Furthermore, the recyclability of [OMim]Br was investigated. The recovery rate of [OMim]Br could reach 95.0 wt%, and the recycled [OMim]Br still had effects on the synthesis of γ-AlOOH and γ-Al2O3.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Ning Xiang,Xiaojin Han,Yarong Bai,Qiaoyan Li,Jianfeng Zheng,Yulin Li,Yaqin Hou,Zhanggen Huang
Supported noble metal catalysts have been widely utilized for HCHO catalytic oxidation. When the active components are fixed, the altering and regulation of the supports would have a huge effect on catalytic performance. Here, two types of Pd/γ-Al 2 O 3 catalysts with different support size (micro-γ-Al 2 O 3 and nano-γ-Al 2 O 3 , respectively) were fabricated and used for HCHO oxidation. Compared with the micro-sized counterpart, the Pd/nano-γ-Al 2 O 3 catalyst exhibited much superior HCHO oxidation performance which could totally oxidize 160 ppm of HCHO into harmless CO 2 under a WHSV of 100,000 mL g cat −1 h −1 at room temperature. Multiple characterizations including XRD, BET, TEM, CO chemisorption, FT-IR, O 2 -TPD, XPS and in situ DRIFTS were implemented to study the effect of γ-Al 2 O 3 support size on physicochemical properties of Pd/γ-Al 2 O 3 catalysts and elucidate the structure-activity relationship. The results revealed that large specific surface area, rich surface OH groups as well as high curvature of nano-γ-Al 2 O 3 not only facilitated HCHO adsorption, but also stabilized highly dispersed Pd species which then promoted the activation of oxygen and boosted formate species decomposition, and consequently leading to the enhanced HCHO oxidation performance of Pd/nano-γ-Al 2 O 3 . This work deepens the comprehension of support size-dependent activity of Pd/γ-Al 2 O 3 catalysts for HCHO oxidation and provides an alternative method to prepare high-performance Pd catalysts for HCHO oxidation.
研究领域:
催化化学
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环境科学
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DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 13
·2215
·
IF 5.719
Huijun Song,Jingjing Li,Guan Sheng,Yinling Zhang,Ahmad Azmin Mohamad,Juan Luo,Zhangnan Zhong,Wei Shao
The oxygen evolution reaction (OER) occurs at the anode in numerous electrochemical reactions and plays an important role due to the nature of proton-coupled electron transfer. However, the high voltage requirement and low stability of the OER dramatically limits the total energy converting efficiency. Recently, electrocatalysts based on multi-metal oxyhydroxides have been reported as excellent substitutes for commercial noble metal catalysts due to their outstanding OER activities. However, normal synthesis routes lead to either the encapsulation of excessively active sites or aggregation during the electrolysis. To this end, we design a novel core–shell structure integrating CoMoO4as support frameworks covered with two-dimensional γ-FeOOH nanosheets on the surface. By involving CoMoO4, the electrochemically active surface area is significantly enhanced. Additionally, Co atoms immerge into the γ-FeOOH nanosheet, tuning its electronic structure and providing additional active sites. More importantly, the catalysts exhibit excellent OER catalytic performance, reducing overpotentials to merely 243.1 mV a versus 10 mA cm−2. The current strategy contributes to advancing the frontiers of new types of OER electrocatalysts by applying a proper support as a multi-functional platform.Keywords:γ-FeOOH nanosheets;CoMoO4@γ-FeOOH heterojunction;oxygen evolution reaction
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
Solid Fuel Chemistry
·
2022
·Vol. 56
·期 1
·37-44
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IF 0.829
Wang Ruiyu,Sun Bingkang,Zhu Jiliang,Fan Xing
Abstract Nano γ-Al 2 O 3 support was prepared by sol-gel method, and the Mg 2 Si/γ-Al 2 O 3 catalyst was prepared by impregnation method from Mg 2 Si and the γ-Al 2 O 3 support. The catalyst was characterized by X-ray diffraction, N 2 adsorption-desorption, scanning electron microscopy and CO 2 temperature-programmed desorption analysis. The catalytic hydrocracking of lignite-related modelcompounds, 1-methoxynaphthalene (1-MON) and bibenzyl ether (BE), was investigated. Mg 2 Si was well distributed on the surface and in the voids of γ-Al 2 O 3 support. The Mg 2 Si/γ-Al 2 O 3 catalyst had high specific surface area, large amount of mesopores, strong basicity, and exhibited high catalytic efficiency in hydrocracking of 1-MON and BE due to the synergic effect between Mg 2 Si and γ-Al 2 O 3 . Under an initial hydrogen pressure of 3 MPa and reaction time of 60 min, the conversion of 1-MON and BE reached 100% when the reaction temperatures were 225 and 175°C, respectively. The selectivities for naphthalene and toluene were close to 100%, only traces of the hydrogenated products were detected. After 4 cycle tests, the catalytic activity of Mg 2 Si/γ-Al 2 O 3 catalystdropped to 50%.
研究领域:
化学工程
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催化材料
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
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IF 4.192
Lei Wang,Yongmei Xia,Lingqia Su,Jing Wu
γ-Cyclodextrin (γ-CD), a cyclic oligosaccharide containing eight glucose units linked by α-1,4-glycosidic bonds, can be produced from starch using cyclodextrin glycosyltransferase (CGTase). Unfortunately, this enzymatic process produces mixtures of α-, β-, and γ-CD. In this study, amino acid residues in the subsite −3 (T47 and F91) and the central subsite (Y186) of Bacillus clarkii γ-CGTase were modified to improve the γ-CD production. The cyclization activities and product specificities of mutants T47H and F91W were similar to those of the wild-type. The cyclization activities of mutants F91N and F91L were significantly greater than those of the wild-type but their γ-CD product specificities were lower. Finally, the central subsite mutant Y186W displayed a γ-CD specificity (94.6%) significantly greater than that of the wild-type (77.1%). To maximize the γ-CD yield, the effects of added complexing agents were investigated. Among the cyclic complexing agents tested, low-boiling cyclododecanone was the smallest that precipitated with γ-CD. When cyclododecanone was used with Y186W, the total CD yield reached 72.6%, and 96.6% of the product was γ-CD. These results, which represent the highest γ-CD yield ever reported, may provide a way to improve large-scale γ-CD preparation and expand the uses of γ-CD in the future.
研究领域:
生物化学
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酶工程
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产品关联
DOI
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
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2019
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IF 4.959
Jin Feng,Qingshan Shi,Yulian Li,Jianfei Huang,Ruimin Li,Xiulin Shu,Wenru Li,Xiaobao Xie
Nanocomposites composed of Ag and γ-Fe 2 O 3 nanoparticles within poly-γ-glutamic acid (γ-PGA) derived amorphous carbon nitride (a-CN) films (Ag + γ-Fe 2 O 3 @a-CN) were synthesized by a one-step facile pyrolysis strategy. Transmission electron microscopy analysis shows that Ag and γ-Fe 2 O 3 nanoparticles were obtained in situ and homogeneously dispersed on the a-CN matrix. The average size of nanoparticles was 8.1 nm. The presence of γ-Fe 2 O 3 , Ag, and a-CN in the nanocomposite was confirmed by X-ray diffraction analysis, UV–visible absorption spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Ag + γ-Fe 2 O 3 @a-CN catalyzed the degradation of methyl orange. This catalyst was also recycled ten times by magnetic separation without any loss in efficiency. Ag + γ-Fe 2 O 3 @a-CN exhibited strong antibacterial activity against E . coli and S . aureus . It also exhibited excellent antibacterial activity even after 20 times magnetic recycling. This indicates that this is a promising recyclable antibacterial and catalyst for environmental applications.
研究领域:
材料科学
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纳米技术
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环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
Electronics
·
2025
·Vol. 14
·期 5
·1050
·
IF 2.6
Xiang Gao,Ying Chen,Pengcheng Xu,Dan Zheng,Xinxin Li
The selective detection of propane gas molecules using semiconductor gas sensors has always been a challenge within research. In this study, we successfully synthesized a γ-Fe2O3nanomaterial with a selective catalytic effect on propane and loaded it onto a ZnO sensing material to construct a double-layer microsensor, which showed good sensing response characteristics in the detection of the refrigerant R290 (which is mainly propane). In addition, we also prepared a series of iron oxides, including nanomaterials such as α-Fe2O3, Fe3O4, and FeO, as well as γ-Fe2O3materials with different specific surface areas obtained at various processing temperatures, and we carried out gas sensing research on R290. The results show that the γ-Fe2O3material has a better sensitivity to R290, and the γ-Fe2O3material calcined at 200 °C shows the best performance. Our results can provide a theoretical basis for the design and optimization of semiconductor gas sensors for alkane detection.
研究领域:
材料科学
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传感器技术
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DOI
高影响因子
Small
·
2017
·Vol. 13
·期 18
·1604033
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IF 8.643
Shuo Chen,Xuemei Liu,Xvsheng Qiao,Xia Wan,Khurram Shehzad,Xianghua Zhang,Yang Xu,Xianping Fan
An effective colloidal process involving the hot-injection method is developed to synthesize uniform nanoflowers consisting of 2D γ-In 2 Se 3 nanosheets. By exploiting the narrow direct bandgap and high absorption coefficient in the visible light range of In 2 Se 3 , a high-quality γ-In 2 Se 3 /Si heterojunction photodiode is fabricated. This photodiode shows a high photoresponse under light illumination, short response/recovery times, and long-term durability. In addition, the γ-In 2 Se 3 /Si heterojunction photodiode is self-powered and displays a broadband spectral response ranging from UV to IR with a high responsivity and detectivity. These excellent performances make the γ-In 2 Se 3 /Si heterojunction very interesting as highly efficient photodetectors.
研究领域:
材料科学
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光电子学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 7
·期 2
·466-480
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IF 5.287
Sijia Liu,Xin Liang,Jie Zhang,Biaohua Chen
Two different kinds of γ-Al2O3 precursors: stick-like ammonium aluminum carbonate hydroxide and willow leaf-like boehmite could be selectively synthesized via a facile hydrothermal method by just adjusting reaction temperature. After heat treatment, γ-Al2O3 with two different morphologies (stick-like and willow leaf-like) were synthesized and used as supports for CoMo hydrodesulfurization catalysts. Fourier transform infrared spectroscopy of pyridine adsorption and NH3-temperature-programmed desorption showed that stick-like γ-Al2O3 (ACH) and willow leaf-like γ-Al2O3 (AOH) exhibited a lower Lewis acidity than commercial γ-Al2O3. X-ray diffraction indicated that CoMo oxidic catalysts supported on ACH and AOH contained more β-CoMoO4 phase. X-ray photoelectron spectroscopy and high resolution transmission electron microscopy revealed that after presulfurization, more CoMoS active sites and multilayered (Co)MoS2 slabs formed on ACH and AOH supports, thereby creating catalysts with a higher hydrodesulfurization activity in the hydrodesulfurization of thiophene and 4,6-dimethyldibenzothiophene.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2023
·
IF 1.8
Kai Fei,Zhuo Yi Dong,Li Shi,Xuan Meng,Naiwang Liu
Transformer oil plays a critical role in ensuring the insulation and normal operation of power transformers. However, during operation, the transformer oil would undergo oxidation and degradation, leading to the formation of acids and polar compounds that increase its acidity and degrade its performance. Hence, the recycling and regeneration of aged transformer oil is an essential practice in transformer maintenance, contributing significantly to the extension of a transformer's operational lifespan and the reduction of potential risks. Adsorption separation is a preferred method for regeneration, offering simplicity and high efficiency. This study focuses on impregnated γ-Al 2 O 3 as an adsorbent for acidity removal in waste transformer oil. We conducted static adsorption experiments to investigate the optimal loading amount of the active component and the best calcination temperature for acid removal. XRD technique is employed to monitor the phase changes of the carrier during the calcination process. BET analysis is used to observe variations in the specific surface area and pore volume of the adsorbent during the modification process. DTG-TGA is utilized to assess the weight loss during the calcination process. FTIR is employed to observe changes in functional groups during modification and adsorption processes. Along with these investigations, a study is also carried out to assess the dynamic acid removal performance of the acid-removing adsorbent loaded into a fixed bed. The findings contribute to the development of sustainable methods for regenerating transformer oil, ensuring efficient and environmentally friendly operations.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2022
·
IF 12.545
Yanli Zhou,Jiaxiang Liu,Hui Dong,Zi Liu,Lu Wang,Qiaoxia Li,Jianhua Ren,Yintang Zhang,Maotian Xu
Interferon-gamma (IFN- γ ) is one kind of crucial inflammatory cytokines, and its expression level is closely associated with various disease progressions. This work addresses the development of a sensitive and specific electrochemical assay for detection of IFN- γ by combing the recognition unit of aptamer with the signal reporter of target-induced silver nanoclusters (AgNCs). For biosensor preparation, the gold nanoparticles (AuNPs) immobilized on the amine-terminated electrode surface provided electrochemical interfaces for the self-assembly of C-rich modified aptamers. Then, the aptamer recognized IFN- γ and the free aptamer hybridized with conjugated DNA sequences . After the nuclease-catalyzed cleavage of DNA duplex, in situ-generated AgNCs in the C-rich template was utilized as the electrochemical indicator for IFN- γ detection. The present method demonstrated a good performance for detection of IFN- γ with a low detection limit of 1.7 pg mL −1 . This aptasensor was verified to be applied for the evaluation of IFN- γ secreted by cell.
研究领域:
生物化学
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分析化学
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纳米技术
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免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 11
·3402-3412
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IF 2.911
Bao Qiang,Qi Hui,Zhang Chunlei,Ning Chunli,Zhang Yi,Jiang Ye,Wu Yifan,Gui Wenying,Wang Zhenlu
Abstract In this work, titanium-doped mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) was prepared by an evaporation-induced self-assembly method and used as a carrier of Ba/γ-Ti–Al 2 O 3 catalyst to catalyze the aldol condensation of methyl acetate with formaldehyde to methyl acrylate in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N 2 adsorption–desorption, pyridine absorption performed via Fourier transform infrared spectroscope (Py-IR), and NH 3 and CO 2 temperature-programmed desorption (NH 3 and CO 2 -TPD). Experimental results indicated that the doping of the titanium species into the frame work of mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) had a significant influence on the catalytic activity via modifying the acid–base surface properties of the catalyst. Furthermore, the Ba/γ-Ti–Al 2 O 3 catalyst demonstrated excellent catalytic performance, with a methyl acetate conversion rate of 50% and methyl acrylate selectivity up to 90.2%. Compared with the Ba/Al 2 O 3 catalyst, the Ba/γ-Ti–Al 2 O 3 catalyst had better catalytic activity, stability and potential for practical application, which was likely due to an increased number of Lewis acid sites, especially the medium acid sites. Graphical Abstract Barium supported mesoporous γ-Ti–Al 2 O 3 catalyst was found to be an effective catalyst for vapor phase aldol condensation of methyl acetate with formaldehyde.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）