JOURNAL OF THE ENERGY INSTITUTE
·
2016
·
IF 1
Nan Li,Wei-Yan Xia,Chang-Wei Xu,Shuang Chen
This study investigated Pt/C and Pd/C catalysts promoted by Au for glycerol electrooxidation in alkaline medium . The results show that addition of Au can significantly promote the catalytic activity and stability of Pt/C and Pd/C for glycerol electrooxidation. The catalysts with a weight ratio of 4:1 for Pt to Au and Pd to Au show the best performance for glycerol electrooxidation and the PtAu(wt 4:1)/C shows a better performance than the PdAu(wt 4:1)/C. Glycerol electrooxidation on the PdAu(wt 4:1)/C has a better stability than that on the Pt/C. The results show that the PdAu(wt 4:1)/C can give a better discharge performance than the Pt/C in a direct glycerol fuel cell. Electrooxidation of pre-adsorbed CO has been used to explain the results.
研究领域:
化学
·
催化科学
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 4
·1-14
·
IF 2.5
Guo Chenxi,Yang Xin,Zhang Xiaxiang,Li Hongtao,Liao Mingdong,Huang Qizhong
To shorten the manufacturing process and enhance the ZrC content, C/C-SiC-ZrC composites were prepared using the nano-filler slurry infiltration method in combination with precursor infiltration and pyrolysis method. The effect of ZrC filler sizes on densification, microstructure, and properties of composites was studied. Results revealed that the ZrC content and density of the C/C-SiC-ZrC composites are inversely correlated to the filler size. The composites with nano-fillers reach the highest density of 2.67 g cm −3 as well as the lowest open porosity of 1.21%. After being ablated under oxyacetylene flame for 60 s, the composites with nano-fillers owns the lowest linear ablation rate and surface temperature, with 10 μms −1 and 2700 °C. Due to the highest ZrC content and best film-forming ability of nano-fillers, ZrO 2 outer layer with the densest structure can provide an enhanced protective effect, and the thickness of the oxide layer decreases from 509 to 264 μm as compared with micron fillers. Therefore, the oxidation damage of the composites is reduced, and the thickness of the SiC depletion layer decreases simultaneously. The above results further demonstrate that introducing ZrC nano-filler to the C/C-SiC-ZrC composites can considerably improve their ablative properties at 2700 °C.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Wang Shifu,Li Fuhua,Zhao Jian,Zeng Yaqiong,Li Yifan,Lin Zih-Yi,Lee Tsung-Ju,Liu Shuhui,Ren Xinyi,Wang Weijue,Chen Yusen,Hung Sung-Fu,Lu Ying-Rui,Cui Yi,Yang Xiaofeng,Li Xuning,Huang Yanqiang,Liu Bin
Manipulation C-C coupling pathway is of great importance for selective CO 2 electroreduction but remain challenging. Herein, two model Cu-based catalysts, by modifying Cu nanowires with Ag nanoparticles (AgCu NW) and Ag single atoms (Ag 1 Cu NW), respectively, are rationally designed for exploring the C-C coupling mechanisms in electrochemical CO 2 reduction reaction (CO 2 RR). Compared to AgCu NW, the Ag 1 Cu NW exhibits a more than 10-fold increase of C 2 selectivity in CO 2 reduction to ethanol, with ethanol-to-ethylene ratio increased from 0.41 over AgCu NW to 4.26 over Ag 1 Cu NW. Via a variety of o perando /in-situ techniques and theoretical calculation, the enhanced ethanol selectivity over Ag 1 Cu NW is attributed to the promoted H 2 O dissociation over the atomically dispersed Ag sites, which effectively accelerated *CO hydrogenation to form *CHO intermediate and facilitated asymmetric *CO-*CHO coupling over paired Cu atoms adjacent to single Ag atoms. Results of this work provide deep insight into the C-C coupling pathways towards target C 2+ product and shed light on the rational design of efficient CO 2 RR catalysts with paired active sites.
研究领域:
材料科学
·
电化学
·
催化反应
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Asian Journal of Organic Chemistry
·
2018
·Vol. 7
·期 8
·1626-1634
·
IF 2.496
Wen-Jing Pan,Zhong-Xia Wang
Graphical Cut my bonds into pieces : The C−H benzylation of oxazoles and benzoxazoles with benzyl trimethylammonium triflates was performed under mild conditions via Pd-catalyzed C−H/C−N cleavage. The method exhibits a wide scope of substrates and good compatibility of functional groups. The C−H benzylation of oxazoles and benzoxazoles with benzylic ammonium triflates was performed in reasonable to good yields via Pd-catalyzed C−H/C−N cleavage. The method exhibits a wide scope of azoles and benzylic ammonium triflates. A range of functional groups including F, CF 3 , COOEt, C(O)NMe 2 , OMe, OPh, pyridyl and thienyl groups can be tolerated.
研究领域:
有机化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 3
·258
·
IF 4
Ling Xie,Zilong Huang,Yapeng Zhan,Jiahao Huang,Chao Wang,Riyang Shu,Junyao Wang,Libin Lei,Jianping Liu,Zhipeng Tian,Ying Chen
Cleavage of C-C bonds is crucial for hydrogen production via aqueous phase reforming of biomass-derived oxygenates. In this study, the hydrogen production performance and C-C bond cleavage capacity of Ni-W/AC catalysts with varying W/Ni ratios are evaluated using ethylene glycol as a model compound. A series of APR experiments conducted suggests that Ni-0.2W/AC catalyst exhibits the highest C1/C2+ratio of 15.87 and achieves a hydrogen yield of 47.76%. The enhanced Ni-W bimetallic interactions, which significantly improve the efficiency of C-C bond cleavage and increase catalyst activity by promoting active site dispersion, are confirmed by detailed characterization techniques. Further analysis of product distribution provides insights into the reaction pathways of ethylene glycol and the reaction mechanism for ethanol during aqueous phase reforming. All the results indicate that this catalytic reforming method effectively facilitates C-C bond cleavage and hydrogen production, contributing to a better understanding of APR mechanisms for biomass-derived oxygenates.
研究领域:
催化化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 38
·32202-32211
·
IF 3.289
Changyan Wu,Xinwen Peng,Linxin Zhong,Xuehui Li,Runcang Sun
Catalytic process is the key process for many chemical industries. In this study, a novel heterogeneous Pd (CMH–Pd(0)) has been prepared by the deposition of palladium nanoparticles (Pd NPs) onto the surface of carboxymethyl functionalized hemicelluloses using ethanol as solvent and in situ reducing agent. The as prepared catalyst was characterized by TEM, HR-TEM, XRD, FT-IR, TGA and XPS. The loading level of Pd in the CMH–Pd(0) catalyst was 0.38 mmol g−1. The catalyst showed high catalytic activity and versatility towards Heck coupling reactions under aerobic conditions and could be readily recovered and reused in at least five successive cycles without obvious loss in activity. The catalyst is promising for its renewability, environmental benefits, efficient catalytic activity, mild reaction conditions, simple product work-up and easy catalyst recovery.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2024
·Vol. 7
·期 6
·1-14
·
IF 23.2
Qiu Jiahang,Zhang Mu,Zhao Rongzhi,Sun Xudong,He Dianning
The quest for broadband electromagnetic wave absorption to satisfy the demands of various fields has emerged as a prominent research focus in the domain of electromagnetic wave absorption. By considering the effects of magnetic loss and polarization loss across different frequency bands, the development of composite materials incorporating magnetic metal particles and single metal atoms may facilitate an expansion of the electromagnetic wave absorption frequency range. Consequently, we synthesized FeCo@C/Ni@C composites derived from FeCo Prussian blue analogues and polydopamine through wet chemistry and pyrolysis methods. The chelation mechanism of polydopamine, combined with the physical barrier effect provided by Zn ions during synthesis, endows the FeCo@C/Ni@C composite with low-frequency magnetic loss characteristics from the FeCo alloy, high-frequency dipole polarization losses attributed to Ni atoms, and conductivity losses arising from the coupled carbon matrix. Ultimately, the composite exhibits exceptional electromagnetic wave absorption performance: at a thickness of 2.26 mm, it achieves a minimum reflection loss value of − 50.1 dB along with an effective absorption bandwidth reaching up to 6.0 GHz. In summary, this work presents a novel strategy for enhancing broadband absorption capabilities in electromagnetic wave absorbing materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Ting Li,Jiantao Bi,Huajing Li,Qing Li,Yuangang Li
The synergistic coupling of photocatalytic C C bond construction and H 2 evolution presents a promising strategy for concurrent organic synthesis and sustainable H 2 evolution. Nevertheless, precisely regulating the reaction pathways to enhance the selectivity of target products remains a challenging. Here, the Sv-CdS/TiO 2 Ni 2 P photocatalyst containing sulfur vacancies was synthesized via calcination, achieving highly selective conversion of 4-pyridinemethanol into the C C coupling product 1,2-di-(4-pyridyl)-1,2-ethanediol under visible-light irradiation, with a selectivity of 96.59 %. In comparison, the M-CdS/TiO 2 Ni 2 P photocatalyst prepared by mechanical mixing exhibits superior H 2 evolution activity of 6.48 mmol·g -1 ·h -1 . Mechanism studies reveal that 4-pyridinemethanol interacts with the Sv-CdS/TiO 2 Ni 2 P photocatalyst through the N atom, which preferentially activates the sp 3 C H bond of 4-pyridinemethanol to generate •CH(OH)C 5 H 4 N radical for further C C coupling reaction. This work not only highlights the selective regulation of the 4-pyridinemethanol C C coupling pathway by sulfur vacancies engineering, but also provides new insights for achieving efficient photocatalytic organic synthesis and green H 2 evolution.
研究领域:
光催化
·
有机合成
·
材料科学
·
环境化学
·
能量转换
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yanyan Wang,Yu Liu,Jiyang Li,Yuanyuan Liu,Weiqiang Zhang,Mingming Yang,Yajun Jian,Ping Zuo,Ziwei Gao
The position of Pd species in/on zeolites is crucial for the activity of metal/metal oxide catalysts. It is still a challenge to highly disperse and stabilize the metal species on zeolites and shorten diffusion paths to maintain high catalytic activity. Here, we report an effective strategy for preparing highly efficient zeolite-supported Pd(II) catalysts by positioning Pd(II) species on the surface of a zeolite with an anion framework based on the principle of charge balance. The catalyst was prepared in situ in a C–C cross-coupling reaction. Due to the change in the metal–support interaction, Pd species have migrated from the inside to the surface of the zeolite, which shortens the diffusion path of reactants and thus ensures the high activity of the catalyst. Pd species exhibit aggregation resistance in alkaline systems and tend to be confined in the traps with high charge density. Compared to unactivated Pd@USY, the efficiency of the activated catalysts has at least doubled in catalyzing the Sonogashira and Suzuki–Miyaura reactions. This study represents a new activation approach for zeolite-supported Pd catalysts, which may help to design efficient catalysts.
研究领域:
催化化学
·
材料化学
·
有机合成
·
纳米催化
·
多相催化
✓ 已验证
DOI
高影响因子
PLANT JOURNAL
·
2021
·Vol. 106
·期 2
·351-365
·
IF 6.486
Cheng-Yong Feng,Shan-Shan Li,Goro Taguchi,Qian Wu,Dan-Dan Yin,Zhao-Yu Gu,Jie Wu,Wen-Zhong Xu,Cheng Liu,Liang-Sheng Wang
SUMMARY Lotus plumule, the embryo of the seed of the sacred lotus ( Nelumbo nucifera ), contains a high accumulation of secondary metabolites including flavonoids and possesses important pharmaceutical value. Flavonoid C -glycosides, which accumulate exclusively in lotus plumule, have attracted considerable attention in recent decades due to their unique chemical structure and special bioactivities. As well as mono- C -glycosides, lotus plumule also accumulates various kinds of di- C -glycosides by mechanisms which are as yet unclear. In this study we identified two C -glycosyltransferase (CGT) genes by mining sacred lotus genome data and provide in vitro and in planta evidence that these two enzymes (NnCGT1 and NnCGT2, also designated as UGT708N1 and UGT708N2, respectively) exhibit CGT activity. Recombinant UGT708N1 and UGT708N2 can C -glycosylate 2-hydroxyflavanones and 2-hydroxynaringenin C -glucoside, forming flavone mono- C -glycosides and di- C -glycosides, respectively, after dehydration. In addition, the above reactions were successfully catalysed by cell-free extracts from tobacco leaves transiently expressing NnCGT1 or NnCGT2. Finally, enzyme assays using cell-free extracts of lotus plumule suggested that flavone di- C -glycosides (vicenin-1, vicenin-3, schaftoside and isoschaftoside) are biosynthesized through sequentially C -glucosylating and C -arabinosylating/ C -xylosylating 2-hydroxynaringenin. Taken together, our results provide novel insights into the biosynthesis of flavonoid di- C -glycosides by proposing a new biosynthetic pathway for flavone C -glycosides in N. nucifera and identifying a novel uridine diphosphate-glycosyltransferase (UGT708N2) that specifically catalyses the second glycsosylation, C -arabinosylating and C -xylosylating 2-hydroxynaringenin C -glucoside.
研究领域:
植物生物化学
·
分子生物学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 117
·96372-96376
·
IF 3.84
Zheng-Jun Wang,Peng-Hui Wang,Jing-Jing Lv,Jiu-Ju Feng,Xinhua Xu,Ai-Jun Wang,Chak-Tong Au,Renhua Qiu
Commercial copolymer Luviset clear (L1), an environmentally benign and efficient ligand, was used to facilitate the catalytic performance of Cu(NO3)2 for homo-coupling of terminal alkynes. A series of substituted aromatic and aliphatic terminal alkynes were investigated. It was found that Cu(NO3)2@L1 can catalyze the C–C coupling reactions without any other base, and the corresponding diynes are generated in good to excellent yield. X-ray photoelectron spectroscopy was used to study the reaction mechanism, and the results evidence a Cu(II)/Cu(I) catalytic system. Additionally, the catalyst can be easily separated and reused without showing significant loss of catalytic activity.
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Xiuzheng Deng,Jiangchuan Liu,Jun Cai,Dan Wang,Huihui Mao,Changhai Liu,Zhongyu Li,Zhenhui Kang,Qian Liang
High production capacity of C 2 products from CO 2 photoreduction remains a significant challenge owing to the difficulty of C-C coupling and weak hydrogenation. Herein, a novel stepwise C-C coupling and hydrogenation mechanism is developed on multisite catalyst to enhance the performance of photocatalytic CO 2 reduction to C 2 products. The active Co cluster, carbon dots (CDs) and Cs 3 Bi 2 Br 9 quantum dots (QDs) are reinforced with robust carbon matrix, which allows to accelerate mass/electron transport and improve stability of catalytic sites, enabling a competitive C 2 H 4 evolution rate of 57.60 μmol g cat −1 h −1 with 67.70 % C 2 H 4 selectivity. In situ experiments coupled with theoretical calculations verify that Co and CDs capture photogenerated electrons from Cs 3 Bi 2 Br 9 to form key intermediate Co-*CO-*CO-CDs. After *CO-*CO coupling on Co site, the proximal CDs provide plenty of protons to conduct continuous hydrogenation toward coupling site until C 2 H 4 is formed. This study paves a novel pathway to regulate C-C coupling and hydrogenation for CO 2 conversion to C 2 hydrocarbons.
研究领域:
催化化学
·
环境科学
·
材料科学
·
物理化学
·
能源化学
·
纳米科技
✓ 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）