JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 94
·期 6
·1958-1967
·
IF 2.659
Jifan Li,Duo Li,Chun-Ling Liu,Chunli Xu,Wen-Sheng Dong
BACKGROUND Glycerol is a versatile platform compound to produce valuable chemicals. One-pot direct conversion of glycerol into methyl lactate with methanol as solvent is very attractive, because it can reduce intermediate steps and avoid the separation of glycerol/methanol mixtures. RESULTS A series of tin (Sn)-exchanged montmorillonite(M)-supported Au catalysts were prepared by a combination of ion exchange and colloidal deposition methods, and designed as bifunctional catalysts containing gold (Au) and solid acid. These catalysts were employed for one-pot conversion of glycerol to methyl lactate in methanol. The Au/Sn(20)-Mt catalyst gave a high yield of methyl lactate of 54% upon conversion of 0.25 mol L –1 glycerol methanol solution over 0.07 g catalyst at 210 °C under 3 MPa air for 5 h. The good performance of Au/Sn(20)-Mt was ascribed to the coexistence of small Au particle and abundance of acid sites. The glycerol conversion remained almost unchanged in the five recycled runs, whereas the methyl lactate yield decreased after the first run but kept stably in the later four catalytic runs. CONCLUSIONS Among the series of Sn-exchanged Mt-supported Au catalysts, Au/Sn(20)-Mt showed the highest glycerol conversion and methyl lactate yield. Containing both small Au particles and having an abundance of acid sites contributed to the excellent catalytic activity of Au/Sn(20)-Mt. © 2019 Society of Chemical Industry
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Li Sun,Tiantian Ma,Jun Zhang,Xiangxin Guo,Chenglin Yan,Xianghong Liu
Alloy-type materials hold a great potential as the negative electrodes for next generation lithium-ion batteries with high energy and low cost. However, the huge volume expansion of alloy-type materials caused by lithium alloying inevitably leads to poor cycle stability. Herein, we propose a rational design of a sandwich structure of carbon/Sn/carbon hollow spheres by a template-engaged method. The structure effect of the novel carbon/Sn/carbon spheres on the lithium storage performances is elucidated by various means of characterization and electrochemical tests. A stable and high reversible capacity of 1100 mA h g −1 is retained after 130 cycles at 0.1 A g −1 , significantly higher than that (187 mA h g −1 ) of Sn/carbon hollow spheres. Furthermore, a superior rate capability is obtained for carbon/Sn/carbon spheres, e.g., showing a high capacity of 430 mA h g −1 at 5 A g −1 . The excellent electrochemical properties of carbon/Sn/carbon against Sn/carbon are ascribed to a unique nano-confinement from the double-shelled carbons with very good structure stability and contribution of pseudocapacitive storage of lithium. These results indicate that the sandwich structure of carbon/Sn/carbon is highly effective to design electrode materials with enhanced performances.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Guoqiang Li,Kai Li,Long Yang,Jinfa Chang,Rongpeng Ma,Zhijian Wu,Junjie Ge,Changpeng Liu,Wei Xing
Reducing the noble-metal loading without sacrificing the catalytic performance of the oxygen evolution reaction (OER) catalysts is paramount yet highly challenging. Herein, IrO2@Ir/TiN electrocatalysts employing TiN as the support have been developed and shown high efficiency toward OER. TiN is found not only to disperse the IrO2@Ir nanoparticles effectively but also to exert the electronic modulation of Ir by downshifting its d-band center of 0.21 eV compared to pure IrO2. Excitingly, TiN remarkably enhances the catalytic performance of Ir, where the overpotential to achieve the current density of 10 mA cm–2 is only 265 mV for the IrO2@Ir/TiN (60 wt %) catalyst. As a result, 71.7 wt % of the Ir metal can be saved to compare with the commercial Ir-black counterpart. Moreover, TiN can inhibit the aggregation and oxidative dissolution of Ir species, thereby enhancing the operational stability. The combined advantages of TiN open a new solution to reduce the anodic catalyst cost through boosting the catalytic activity and stability.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 21
·5526-5534
·
IF 5.365
Songyan Jia,Xinjun He,Jiao Ma,Kangjun Wang,Zhanwei Xu,Z. Conrad Zhang
The synthesis of furan compounds by renewable carbohydrates has emerged as an important path toward biomass utilization. 5-Hydroxymethylfurfural (5-HMF) and furfural are two typical furan products from cellulosic and hemicellulosic materials, of which the primary components (hexoses and pentoses) undergo selective dehydration. It is worth noting that hemicellulose is rich in not only pentoses but also hexoses, indicating the feasibility of producing 5-HMF and furfural simultaneously. However, research on the production of 5-HMF from hemicellulose-derived hexoses remains lacking. Mannose, a major hexose component of hemicellulose, has been previously found to be a suitable feedstock for 5-HMF production in the presence of homogeneous catalysts, such as metal salts. In this work, Cr-, Al- and Sn/MCM-41 catalysts were prepared by a simple impregnation method and characterized. The conversion of mannose into 5-HMF was evaluated in dimethyl sulfoxide (DMSO) solvent. It was found that the as-synthesized Sn/MCM-41 catalyst showed a superior activity to Cr/MCM-41 and Al/MCM-41. Mannose could be effectively converted into 5-HMF with a yield of ∼45% and ∼88% conversion at 150 °C after 60 min, which were comparable to reported results over heterogeneous catalysts. The as-synthesized Sn/MCM-41 catalyst was also efficient for the conversion of glucose and fructose with reasonable 5-HMF yields. The Sn/MCM-41 catalyst could be reused for eight consecutive cycles without significant loss of catalytic activity.
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 9
·期 22
·4199-4205
·
IF 4.803
Yijin Shu,Hang Cheong Chan,Lifang Xie,Zhangping Shi,Yi Tang,Qingsheng Gao
Graphical Bi bi baby : Bimetallic Pt-Sn catalysts supported by hydrogenated MoO x (Pt-Sn/H-MoO x ) deliver both a high selectivity and activity for the selective hydrogenation of functionalized nitroarenes under mild conditions. The atom-rearranged bimetallic Pt-Sn surface and the electronic metal–support interactions with H-MoO x contribute to the high selectivity and activity, respectively. The hydrogenation of functionalized nitroarenes to the corresponding anilines is of great importance in the fine chemical industry and requires high-performance catalysts with a good activity and selectivity. Herein, hydrogenated MoO x (H-MoO x ) supported bimetallic Pt-Sn (Pt-Sn/H-MoO x ) was developed to accomplish selective and efficient hydrogenation. In the case of 4-nitrostyrene, an outstanding selectivity to 4-vinylaniline (≈93 %) with a high turnover frequency (0.094 s −1 ) was achieved under mild conditions ( T =30 °C, P =1 atm). The metal–support interactions contributed to the efficient turnover on the ultrafine nanoparticles, and the atom-rearranged bimetallic Pt-Sn surface promoted the selectivity because of the preferred adsorption of the nitro group. The good efficiency for various functionalized nitroarenes further verified the promise of Pt-Sn/H-MoO x in chemoselective hydrogenation.
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 17
·6551-6560
·
IF 5.287
Xincheng Wang,Fengbing Liang,Chongpin Huang,Yingxia Li,Biaohua Chen
Methods to catalytically convert carbohydrates into lactic acid (LA), which is a versatile platform chemical, have been widely investigated. In this study, siliceous tin phosphates were utilized as reusable Brønsted–Lewis acid bifunctional catalysts during the conversion of 1,3-dihydroxyacetone (DHA) to LA under hydrothermal conditions. The product distribution closely depended on the reaction temperature, catalyst loading and substrate concentration. The highest LA yield of 93.8% was achieved with a complete DHA conversion at 140 °C after 5 h. The reaction was facilitated by the vast presence of Brønsted and Lewis acid sites that were confirmed by both pyridine FTIR and NH3-TPD analysis. The incorporation of silica significantly lowered the Sn content and improved the thermal stability of the tin phosphate catalysts. A possible reaction mechanism was proposed in that the Lewis and Brønsted acid sites synergistically catalyzed the conversion of pyruvaldehyde to LA, which was found to be the rate-determining step. The method allows for facile catalyst separation and recycling while expanding the applicability of silica in the field of biomass-to-chemical conversion.
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 24
·16436-16443
·
IF 4.449
Hongwei Lei,Guang Yang,Yaxiong Guo,Liangbin Xiong,Pingli Qin,Xin Dai,Xiaolu Zheng,Weijun Ke,Hong Tao,Zhao Chen,Borui Li,Guojia Fang
Efficient planar antimony sulfide (Sb2S3) heterojunction solar cells have been made using chemical bath deposited (CBD) Sb2S3 as the absorber, low-temperature solution-processed tin oxide (SnO2) as the electron conductor and poly (3-hexylthiophene) (P3HT) as the hole conductor. A solar conversion efficiency of 2.8% was obtained at 1 sun illumination using a planar device consisting of F-doped SnO2 substrate/SnO2/CBD-Sb2S3/P3HT/Au, whereas the solar cells based on a titanium dioxide (TiO2) electron conductor exhibited a power conversion efficiency of 1.9%. Compared with conventional Sb2S3 sensitized solar cells, the high-temperature processed mesoscopic TiO2 scaffold is no longer needed. More importantly, a low-temperature solution-processed SnO2 layer was introduced for electron transportation to substitute the high-temperature sintered dense blocking TiO2 layer. Our planar solar cells not only have simple geometry with fewer steps to fabricate but also show enhanced performance. The higher efficiency of planar Sb2S3 solar cell devices based on a SnO2 electron conductor is attributed to their high transparency, uniform surface, efficient electron transport properties of SnO2, suitable energy band alignment, and reduced recombination at the interface of SnO2/Sb2S3.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NATURAL PRODUCT RESEARCH
·
2017
·
IF 1.828
Wei-Xun Chunyu,Zhang-Gui Ding,Jiang-Yuan Zhao,Yong-Xia Wang,Xiu-Lin Han,Ming-Gang Li,Meng-Liang Wen
Two new diketopiperazines, named diphenylalazine C (1) and epicoccin U (2), together with six known compounds (3–8) were isolated from the EtOAc extract of the fermentation broth of the tin mine tailings-derived fungus Schizophyllum commune YIM DT 10058. Their structures were elucidated by detailed analysis of spectroscopic data and comparison with related known compounds. Compounds 1 and 2 exhibited weak antibacterial and cytotoxic activities.
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Jiachen Li,Jun Pu,Ziqiang Liu,Jian Wang,Wenlu Wu,Huigang Zhang,Haixia Ma
The energy and power densities of rechargeable batteries urgently need to be increased to meet the ever-increasing demands of consumer electronics and electric vehicles. Alloy anodes are among the most promising candidates for next-generation high-capacity battery materials. However, the high capacities of alloy anodes usually suffer from some serious difficulties related to the volume changes of active materials. Porous supports and nanostructured alloy materials have been explored to address these issues. However, these approaches seemingly increase the active material-based properties and actually decrease the electrode-based capacity because of the oversized pores and heavy mass of mechanical supports. In this study, we developed an ultralight porous nickel to scaffold with high-capacity SnSb alloy anodes. The porous-nickel-supported SnSb alloy demonstrates a high specific capacity and good cyclability for both Li-ion and Na-ion batteries. Its capacity retains 580 mA h g–1 at 2 A g–1 after 100 cycles in Li-ion batteries. For a Na-ion battery, the composite electrode can even deliver a capacity of 275 mA h g–1 at 1 A g–1 after 1000 cycles. This study demonstrates that combining the scaffolding function of ultralight porous nickel and the high capacity of the SnSb alloy can significantly enhance the electrochemical performances of Li/Na-ion batteries.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2016
·Vol. 95
·期 6
·1109-1116
·
IF 1.066
Jianqiang Zhang,Jian Luo,Jun Gao,Dianhua Liu
Catalytic hydrogenation of acetic acid to ethanol was investigated in a fixed-bed micro-reactor with calcium silicate-modified platinum-tin catalyst at mild reaction condition. The modified catalyst exhibited excellent performance for the ethanol synthesis process at relatively low pressure. According to the results of H 2 -pulse chemisorption experiments, the introduction of calcium silicate promoted the dispersion of platinum particles. The NH 3 -TPD and H 2 -TPR results showed the decrease of acid content on catalyst surface and the enhancement of reducibility after the CaSiO 3 modification. Additionally, the results of XPS indicated that Sn (0) was emergent and Pt (2+) was sharply decreased after reduction. Both the H 2 -TPR and XPS results supported the formation of Pt-Sn alloy during the reduction process at 623 K. The Pt-Sn alloy changed the electron density and benefited the free hydrogen dissociation and hydrogenation. The enhancement of reaction temperature and pressure both promoted acetic acid conversion. The kinetic model of power-function type was established to describe the process of hydrogenation. The results of residual analysis confirmed that the raised kinetic model for acetic acid to ethanol reaction was suitable.
✓ 已验证
产品关联
DOI
高影响因子
SOLID-STATE ELECTRONICS
·
2024
·
IF 1.4
Guoxiang Song,Xinan Zhang,Haoxuan Xu
Doping is a useful technique for metal oxide thin-film transistors (TFTs) to adjust the threshold voltage and charge carrier density. However, a notable drawback is the disruption of the microstructure caused by doping crystalline lattice, leading to a partial decrease in charge carrier mobility. In this work, we suggest a surface doping technique that modifies the carrier concentration and passivates the device surface while preserving the channel layer lattice structure through the use of organic dopant molecules. It is shown that tin oxide (SnO 2 ) TFTs doped in this manner typically exhibit improved electrical characteristics, particularly greater mobility and a noticeably lower threshold voltage, without negatively affecting the devices on/off current ratio. Furthermore, compared to pristine devices, bias stress stability and long-term durability are also enhanced. These findings suggest that surface doping may find use in high-performance oxide semiconductor devices and circuits.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Applied Spectroscopy
·
2024
·Vol. 91
·期 4
·903-911
·
IF 0.8
Zheng Zhiheng,Zhang Fan,Liu Yankun,Wang Zhiwu,Pei Yuan,Wu Zhengang,Li Bo,Wei Yingna,Chen Ying,Wei Hengyong,Li Jingwu
TiN–Ag@Ag composite substrates were prepared via ammonia reduction nitridation followed by electrochemical deposition. Fabricated TiN–Ag@Ag substrates were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and ultraviolet-visible spectrophotometry. The surface-enhanced Raman spectroscopy activity of these substrates was evaluated using ibuprofen as the probe molecule. The size of the Ag particles prepared via electrochemical deposition was approximately 1 μm, and Ag nanoparticles with an average particle size of 100 nm were uniformly distributed on the surface of TiN–Ag films. The Raman signal of ibuprofen was significantly enhanced, and the minimum detection concentration of ibuprofen was 10 –5 M. The mechanism by which the TiN–Ag@Ag composite substrate enhanced the Raman signals was analyzed using ultraviolet photoelectron spectroscopy and density functional theory implemented in the Gaussian software. Overall, charge transfer and the local electromagnetic field effect enhanced the Raman signals of ibuprofen.
✓ 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）