APPLIED CATALYSIS A-GENERAL
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2019
·
IF 4.63
Meng Xia,Zheng Shen,Shaoze Xiao,Bo-yu Peng,Minyan Gu,Wenjie Dong,Yalei Zhang
The direct catalytic transformation of raw lignocellulosic biomass into valuable chemicals is of great significance for sustainable production. This work reports the combination of a transition metal chromium with tin in Beta zeolites to efficiently catalyse the conversion of Miscanthus into lactic acid with a yield of 33.4% and a selectivity of 53.2%. On the basis of experiment and kinetic studies , chromium and tin were beneficial for the retro-aldol condensation and isomerization of carbohydrates, respectively. The acidity of the catalyst was investigated based on important insight into the synergetic catalytic mechanism. The strong Lewis acidity possessed by the transition metals was remarkably advantageous for catalysing the retro-aldol fragmentation reaction, while the relatively weak Lewis acidity of the tin species was considered a dominant factor in the isomerization reaction. The coupling of multifunctional active sites provided a new director for the transformation towards lactic acid formation.
研究领域:
催化化学
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可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
Engineering
·
2025
·
IF 11.6
Ying Zhu,Jingjing Liu,Guangzhi He,Shaohua Xie,Wenpo Shan,Zhihua Lian,Fudong Liu,Hong He
Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR catalyst) in diesel vehicles. In this study, a tin (Sn)-modified Ce–Nb mixed-oxide catalyst was synthesized as an NH 3 -SCR catalyst for NO x emission control. After the introduction of Sn, both the NH 3 -SCR activity and the hydrothermal stability of the catalyst were remarkably promoted. Even after hydrothermal aging at 1000 °C, the developed Ce 1 Sn 2 Nb 1 O x catalyst achieved more than 90% NO x conversion at 325–500 °C. Various methods, including N 2 -physisorption, X-ray diffraction, in-situ high-temperature X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption fine-structure spectroscopy, temperature-programmed reduction of hydrogen, temperature-programmed desorption of ammonia, and density functional theory calculations were used to investigate the promotional effects induced by the Sn species. The characterization results showed that the addition of Sn not only promoted the formation of the Ce–Nb active phase but also improved its thermal stability, contributing to the excellent NH 3 -SCR performance and hydrothermal stability. This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO x emission control.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Guo Qiu,Biaohua Chen,Chongpin Huang,Ning Liu,Xiuliang Sun
Methods for the conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF), which is an important platform chemical, have been attracted extensive attention. In present study, Sn modified ionic liquid polymer (PIL-Sn) was prepared by one-pot polymerization of imidazole and epichlorohydrin, and utilized as a novel and efficient catalyst for 5-HMF production. The optimal 5-HMF yield of 51.1% with 99% conversion was obtained from glucose catalyzed by PIL-Sn in dimethyl sulfoxide at 130 °C with reaction time of 1 h. This catalytic system can also be applied for the transformation of other carbohydrates with satisfactory yields. The mechanism of PIL-Sn-catalyzed conversion of glucose to 5-HMF has been studied using density functional theory (DFT) calculations. The DFT results showed that the five-coordinated SnCl 5 - as a preferred species played an important role in the isomerization of glucose to fructose. This research provides a new strategy to design efficient catalysts for 5-HMF synthesis.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2024
·
IF 9.6
Liu Ke-Xin,Tan Ran,Zheng Zhong,Zhao Rui-Rui,Ülgüt Burak,Ai Xin-Ping,Qian Jiang-Feng
Lithium metal, with its exceptionally high theoretical capacity, emerges as the optimal anode choice for high-energy-density rechargeable batteries. Nevertheless, the practical application of lithium metal batteries (LMBs) is constrained by issues such as lithium dendrite growth and low Coulombic efficiency (CE). Herein, a roll-to-roll approach is adopted to prepare meter-scale, lithiophilic Sn-modified Cu mesh (Sn@Cu mesh) as the current collector for long-cycle lithium metal batteries. The two-dimensional (2D) nucleation mechanism on Sn@Cu mesh electrodes promotes a uniform Li flux, facilitating the deposition of Li metal in a large granular morphology. Simultaneously, experimental and computational analyses revealed that the distribution of the electric field in the Cu mesh skeleton induces Li inward growth, thereby generating a uniform, dense composite Li anode. Moreover, the Sn@Cu mesh-Li symmetrical cell demonstrates stable cycling for over 2000 h with an ultra-low 10 mV voltage polarization. In Li||Cu half-cells, the Sn@Cu mesh electrode demonstrates stable cycling for 100 cycles at a high areal capacity of 5 mAh·cm −2 , achieving a CE of 99.2%. This study introduces a simple and large-scale approach for the production of lithiophilic three-dimensional (3D) current collectors, providing more possibilities for the scalable application of Li metal batteries. Graphical abstract
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2017
·Vol. 10
·期 23
·4715-4724
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IF 7.226
Wenda Hu,Yan Wan,Lili Zhu,Xiaojie Cheng,Shaolong Wan,Jingdong Lin,Yong Wang
Graphical Mal to Mol and Dal ! Methylallyl alcohol and diethyl acetal are synthesized from methacrolein by using different Sn-modified Beta zeolites (Sn-β) as catalysts. The Sn-β precalcined in Ar followed by sodium-exchange exhibited the highest selectivity toward the desired products. The possible reaction pathways of the reaction between α,β-unsaturated aldehydes and primary alcohols were investigated and proposed. A new strategy was developed to simultaneously produce two important chemicals, namely, methallyl alcohol (Mol) and diethyl acetal (Dal) from methacrolein in ethanol solvent at low temperature with the use of Beta zeolites modified by tin (Sn-β catalysts). All the Sn-β catalysts were prepared by the solid-state ion-exchange method, wherein the calcination step was conducted under different gas atmospheres. The catalyst precalcined in Ar (Sn-β-Ar) had a reduced number of extra-framework Sn species and enabled more Sn species to be exchanged into the framework as isolated tetrahedral Sn IV , enhancing the catalytic activity of the Meerwein–Ponndorf–Verley (MPV) reaction. The sodium-exchanged Sn-β-Ar, with a reduced number of weak Brønsted acid sites, led to an even better selectivity for Mol, owing to the restriction of the side reactions such as acetalization, addition, and etherification. Under optimized catalyst and reaction conditions, the yield of Mol and Dal reached approximately 90 % and 96 %, respectively. The possible reaction pathways, along with a complex network of side products, was proposed after a detailed investigation through the use of different substrates as reactants. The fine-tuning of Sn-β catalysts through different treatments discussed in this work is of great significance toward the understanding and manipulation of complex reactions between α,β-unsaturated aldehydes and primary alcohols.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 8
·719
·
IF 4.4
Xueyan Li,Zeyi Wu,Xiangyu Song,Denghua Li,Jiajia Liu,Jiatao Zhang
Nowadays, metal oxide semiconductor gas sensors have diverse applications ranging from human health to smart agriculture with the development of Internet of Things (IoT) technologies. However, high operating temperatures and an unsatisfactory detection capability (high sensitivity, fast response/recovery speed, etc.) hinder their integration into the IoT. Herein, a ternary heterostructure was prepared by decorating WO3nanoplates with Au and SnO2nanoparticles through a facial photochemical deposition method. This was employed as a sensing material for 3-hydroxy-2-butanone (3H-2B), a biomarker ofListeria monocytogenes. These Au/SnO2–WO3nanoplate-based sensors exhibited an excellent response (Ra/Rg= 662) to 25 ppm 3H-2B, which was 24 times higher than that of pure WO3nanoplates at 140 °C. Moreover, the 3H-2B sensor showed an ultrafast response and recovery speed to 25 ppm 3H-2B as well as high selectivity. These excellent sensing performances could be attributed to the rich Au/SnO2–WO3active interfaces and the excellent transport of carriers in nanoplates. Furthermore, a wireless portable gas sensor equipped with the Au/SnO2–WO3nanoplates was assembled, which was tested using 3H-2B with known concentrations to study the possibilities of real-time gas monitoring in food quality and safety.
研究领域:
传感器技术
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食品安全
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纳米材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）