Catalysis Science & Technology
·
2015
·Vol. 6
·期 6
·1693-1700
·
IF 5.426
Zhixin Zhang,Yehong Wang,Min Wang,Jianmin Lu,Chaofeng Zhang,Lihua Li,Jingyang Jiang,Feng Wang
We herein report the oxidative C–C coupling of ketones and primary alcohols to produce α,β-unsaturated ketones in the absence of base additives. This cascade synthetic reaction was conducted at 150 °C in 12 h using a heterogeneous CeO2 catalyst. The conversion of acetophenone reached 74% with 89% selectivity to chalcone. A correlation between the CeO2 crystal plane and catalytic performance is established as the catalytic activities decrease in the sequence of (110) > (111) > (100). Characterization using Raman spectroscopy, CO2 temperature-programmed desorption (CO2-TPD), and in situ active site-capping tests has shown that the unusual catalysis of the CeO2 catalyst is attributed to the coexistence of basic and redox active sites. These sites synergistically catalyze the oxidation of alcohols to aldehydes and the aldol condensation to ketones. Moreover, the CeO2 catalyst can be reused several times after calcination to remove the surface-adsorbed substances.
研究领域:
化学
·
催化科学
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DOI
高影响因子
Small
·
2017
·Vol. 13
·期 32
·1701246
·
IF 8.643
Chunli Wang,Lianshan Sun,Feifei Zhang,Xuxu Wang,Qujiang Sun,Yong Cheng,Limin Wang
Highly uniform hierarchical Mo–polydopamine hollow spheres are synthesized for the first time through a liquid-phase reaction under ambient temperature. A self-assembly mechanism of the hollow structure of Mo–polydopamine precursor is discussed in detail, and a determined theory is proposed in a water-in-oil system. Via different annealing process, these precursors can be converted into hierarchical hollow MoO 2 /C and Mo 2 C/C composites without any distortion in shape. Owing to the well-organized structure and nanosize particle embedding, the as-prepared hollow spheres exhibit appealing performance both as the anode material for lithium-ion batteries and as the catalyst for hydrogen evolution reaction (HER). Accordingly, MoO 2 /C delivers a high reversible capacity of 940 mAh g −1 at 0.1 A g −1 and 775 mAh g −1 at 1 A g −1 with good rate capability and long cycle performance. Moreover, Mo 2 C/C also exhibits an enhanced electrocatalytic performance with a low overpotential for HER in both acidic and alkaline conditions, as well as remarkable stability.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
催化化学
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DOI
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Shanshan Shao,Xinggang Hu,Wenbin Dong,Xiaohua Li,Huiyan Zhang,Rui Xiao,Yixi Cai
Aldol condensation of biomass-derives coupled with hydrogenation is a promising route for the production of renewable aviation fuel. In this study, a bifunctional catalyst was prepared to integrate the aldol condensation of cyclopentanone and hydroprocessing for aviation fuel in one pot. Due to its strong mild-basic sites, Mg–Al–O performed the best with the total yield of dimer and trimer of 80.4%. Nickel was screened out to be favorable for hydrogenation. Considering the unsatisfactory porous structure of Ni/Mg–Al–O, the bifunctional catalyst was prepared with activated carbon (AC) as carrier. With Ni loading of 20 wt%, the maximum yield of targeted alkanes reached 81.1% over Ni/Mg–Al–O/AC. The calcination and reduction temperature in the preparation process were both optimized at 550 °C. In the reusability test, the yield of targeted alkanes reduced to 31.6% in the 5th run. To attenuate the hydration effect, n-pentane was introduced as solvent, and the bifunctional Ni/Mg–Al–O/AC performed stably in 5 runs. By the design of bifunctional catalyst based on the theoretical basis to realize the integration of C–C coupling and hydrogenation in one pot, it will promote the development of aviation fuel from biomass in a more sustainable and green way.
研究领域:
催化化学
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能源化学
·
绿色化学
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生物燃料
·
应用化学
·
材料化学
·
工业催化
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Tengfei Xu,Zifeng Pi,Fengrui Song,Shu Liu,Zhiqiang Liu
Unsaturated lipids exhibit different physiological significances due to the different locations of the carbon–carbon double bond (C=C). Identifying lipid isomers with mass-based methods remains challenging. Xia's group has been successfully employed Paternò–Büchi (PB) reaction, a photochemical reaction with UV irradiation , coupled with tandem mass spectrometry (MS/MS) to identify and quantify unsaturated lipids in complex mixtures. However, the existing PB reagents possess certain demerits. In this regard, a new PB reagent that is compatible with various lipidomic analysis platforms must be screened. In this study, we comprehensively evaluated the conditions of the PB reaction and screened benzophenone as a new PB reagent. Benzophenone possesses unique advantages, such as a relative high PB yield; the PB products could be readily distinguished from the reacted lipids based on the added high molecular weight (182 Da); and the benzophenone does not affect the lipids appearance interval for reversed-phase column separation. Furthermore, we optimized the reaction conditions by using benzophenone as a PB reagent and summarized the molecular formulas of the diagnostic ions according to the fragment rules. The proposed PB method has been implemented in shotgun and LC–MS lipidomics. To our best knowledge, this work is the first to report the integrated PB reaction with LC–MS lipidomics for identification of lipid isomers.
研究领域:
分析化学
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脂质组学
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质谱分析
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光化学
·
代谢组学
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DOI
高影响因子
BIOMASS & BIOENERGY
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2026
·
IF 7
Weijie Shen,Li Dong,Shuoqi Pei,Guoqiang Ding,Shanhui Zhu,Yueqing Wang,Guangping Lei,Yulei Zhu
Tandem isomerization and decarbonylation increased furfural yield from 34.4% to 67.9%. • Framework Sn location was governed by T-vacancy distribution in dealuminated H-beta. • Open Sn sites at pore mouths improved furfural selectivity. The asymmetric C-C bond scission of C6 glucose to C5 furfural via a “C5 + C1” retro-aldol pathway represents a promising and important route for the valorization of bio-based sugar resources. However, this transformation still faces major challenges in achieving high selectivity and efficiency, as stable glucopyranose tends to undergo side reactions leading to oligomeric humins. In this work, to enhance furfural yield, Sn atoms were incorporated into the framework of dealuminated H-beta zeolite to construct synergistic active sites for coupling isomerization and decarbonization reactions. The catalytic performance was found to be highly sensitive to the type, spatial location, and coordination environment of framework Sn species. Based on Low-Energy Ion Scattering (LEIS) and X-ray absorption fine structure (XAFS) results, it is demonstrated that open Sn sites located at the pore mouths of H-beta zeolite are conducive to the conversion of glucose into furfural via coupled isomerization-decarbonization pathways. Accordingly, Sn-Al-beta-C, which possesses the highest proportion of open Sn sites, achieves the highest furfural yield of 67.9% at nearly complete glucose conversion, markedly outperforming H-beta (34.4%) and the corresponding physical mixtures. The ratio of open to closed Sn sites can be regulated by controlling the deposition of Sn (IV) species at the pore mouths of H-beta zeolite. The results of this work demonstrate the feasibility of constructing metal–acid bifunctional sites for the direct conversion of glucose to furfural and provide valuable insights for the rational design of efficient metal-modified zeolite catalysts.
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高影响因子
Journal of Energy Storage
·
2026
·
IF 10.7
Ji Ma,Jiazhe Yan,Chang Xu,Jianing Gai,Qinzhen Gong,Xiaotao Dai,Chunting Liu,Fengshou Liu
The electrochemical evolution of heterointerfaces in conversion-type anodes has long been poorly understood. Whether engineered interfaces survive cycling, and if not, how separated phases maintain function, remains unclear. Using two model systems Fe 3 C/Fe 3 O 4 /C (inert conductive phase) and Cu 2 O/Cu/C (oxidizable conductive phase), we uncover two diametrically opposite evolution pathways that are dictated solely by the oxidation behavior of the conductive phase. In the inert Fe 3 C system, the initial core-shell interface completely dissociates. Yet the porous carbon network alone maintains electronic connectivity, creating a remote synergy mode in which the carbon network sustains battery operation by compensating for lost heterointerface contact, without requiring direct interfacial contact between the active phases. In the oxidizable Cu system, we directly visualize a phenomenon. Cu 2 O undergoes an electrochemically driven facet reconstruction from the (111) to the (200) orientation, which progressively lowers the overpotential for the Cu → Cu 2 O reaction and makes the electrode self-optimizing with cycling. Post-mortem electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy provide direct visual evidence for both pathways. Kinetic analysis shows mixed diffusion capacitive control, with the CCC system reaching a 46.5% capacitive contribution at 1.0 mV s −1 . Full cells with K-PBA cathodes achieve 75.0% capacity retention after 1000 cycles at 0.5 A g −1 , demonstrating practical viability. This work challenges the long-held assumption that interfacial retention is necessary for electrochemistry. Instead, it establishes a universal design principle for durable conversion-type anodes. Ensuring electron-transport pathway integrity, whether through direct contact or indirect network connectivity, is the key. The discovery of electrochemically driven facet reconstruction also opens new avenues for controlling surface crystallography under operating conditions.
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产品关联
DOI
高影响因子
Nanoscale
·
2016
·Vol. 8
·期 8
·4681-4687
·
IF 7.76
Zexing Wu,Jie Wang,Lili Han,Ruoqian Lin,Hongfang Liu,Huolin L. Xin,Deli Wang
Investigating active, stable, and low-cost materials for the oxygen reduction reaction is one of the key challenges in fuel-cell research. In this work, we describe the formation of N-doped carbon shell coated Co@CoO nanoparticles supported on Vulcan XC-72 carbon materials (Co@CoO@N–C/C) based on a simple supramolecular gel-assisted method. The double-shelled Co@CoO@N–C/C core–shell nanoparticles exhibit superior electrocatalytic activities for the oxygen reduction reaction compared to N-doped carbon and cobalt oxides, demonstrating the synergistic effect of the hybrid nanomaterials. Notably, the Co@CoO@N–C/C nanoparticles give rise to a comparable four-electron selectivity, long-term stability, and high methanol tolerance; all show a multi-fold improvement over the commercial Pt/C catalyst. The progress is of great importance in exploring advanced non-precious metal-based electrocatalysts for fuel cell applications.
研究领域:
材料科学
·
电化学
·
能源研究
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Qifeng Chen,Guoming Gao,Huailin Fan,Jie Zheng,Lulu Ma,Yanyu Ding,Yanfen Fang,Ran Duan,Xiaofeng Cao,Yanchuan Guo,Dongge Ma,Xun Hu
The surface property of a photocatalyst, including surface acid sites and oxygen vacancies, plays a pivotal role in photocatalytic organic synthesis reactions. Benzoin isopropyl ether (BIE) is usually produced via polycondensation of benzaldehyde and catalyzed with highly toxic cyanide. Here, we report a green photocatalytic approach for the selective synthesis of BIE over WO3 driven by a green-light-emitting diode. The improved photocatalytic activity can be attributed to the synergy of oxygen vacancies (VOs) and acid sites over N-doped WO3 nanobelts. The results revealed that reactant molecules were predominantly adsorbed and activated on surface oxygen vacancies (VOSs) and the Brønsted acid promoted the etherification reaction; the introduction of VOs and nitrogen altered the band structure and electronic properties, resulting in improved photocatalytic activity. Our work provides an efficient approach to the selective photocatalytic synthesis of organics over photocatalysts with finely tuned surface properties and band structures via defect and doping engineering.
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产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Ze Zhang,Cunqian Fang,Yuanqi Weng,Xiao Luo,Qizhong Huang,Huiping Hu
Graphene was introduced into C/C–SiC composites via pressureless impregnation to enhance the mechanical and thermal properties of the composites. The effects of various graphene contents on the mechanical and ablative performances of C/C–SiC composites were investigated. The results showed that the ultimate bending stress and compressive stress of the C/C–SiC composites increased by 28.98% and 23.64%, respectively, after adding 7.25% graphene. Moreover, the ablation rates of the composites were vastly decreased after adding a slight graphene content (2.13%). However, the ablation rates increased with increasing of graphene content, indicating that the benefit of introducing graphene on the ablation property decreased, which was mainly ascribed to the relative reduction in the SiC content. As a result, introducing slight graphene into C/C–SiC composites had the greatest benefit on the anti-ablation performance.
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Xin-bo Xiong,Chun Liu,Xin-Ye Ni,Cai-qing Liang,Xie-rong Zeng
Hydroxyapatite (HA) coatings directly deposited by hydrothermal electrochemical technology (HET) onto carbon/carbon (C/C) composites exhibited a catastrophic failure occurring at the interface of the HA and C/C. To overcome this problem, a polyvinyl alcohol (PVA)/graphene oxide (GO) interlayer (P/G interlayer) was applied on the (NH4)2S2O8-pretreated C/C substrate (named P/G-C/C) by using a dipping method. Subsequently, a calcium phosphate coating was deposited on P/G-C/C, shortened as M-P/G-C/C, by HET, and then converted into HA coating (abbreviated as HA-P/G-C/C) through posthydrothermal treatment. For comparison, HA coating was prepared onto C/C without a P/G interlayer through the same process, which was denoted as HA-C/C. The composition, microstructure, and morphology of the samples were characterized by X-ray diffractometry (XRD), energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), Raman spectra, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). The adhesive performance of the coatings on C/C was measured by a scratch test. Finally, an in vitro bioactivity of the coatings was evaluated in a simulated body fluid solution at 37 °C. Results showed no apparent differences in the morphology and phase of the posttreated coatings, both of which are composed of a dense structure containing needle-like HA crystals. However, the HA-P/G-C/C sample possessed a higher Ca/P ratio and denser interface, thereby exhibiting higher adhesive performance and better bioactivity. The adhesive strength of the HA-P/G coating was observed at a critical load of 41.04 N, which increased by 29.3% relative to the HA coating. Moreover, the failure site was on the HA-P/G coating rather than at the interface. The enhanced adhesive performance was ascribed to the PVA/GO-repairing pits on C/C and PVA and GO toughening effects on the HA coating. In vitro and in vivo tests revealed no statistical significance for the two HA-coated C/C samples, although the HA-P/G coating exhibited better bioactivity, inducing the growth of bonelike apatite than the HA coating.
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yang Zhong,Bo Zhou,Lijun Wang
Fe/FeO x embedded in LDH was prepared by reducing the pre-synthesized [Fe(C 2 O 4 ) 3 ] 3− anions intercalated LDH and used as a multi-functional catalyst for synthesis of C7-C9 compound via transfer hydrogenation between furfural (C5) and short-chain alcohols (C2-C4) and a subsequent aldol reaction of furfural with intermediate short-chain aldehydes in the absence of a homogeneous base with furfuryl alcohol as a byproduct. Screening reaction conditions, evaluation and improvement of the cyclic catalytic performance, and determination of catalytically active components were performed, and the results demonstrated that both high conversion and high selectivity to the C C bond forming product can be obtained under a non-oxidizing atmosphere of Ar or H 2 /Ar mixed gas, a reaction temperature of 140 °C and a reaction time of 4 h; the catalyst was easily deactivated during the cycle experiments, however, its catalytic stability can be effectively improved by depositing Ni with weak reducibility on the surface of Fe nanoparticles at the cost of reducing partial catalytic activity. Fe/FeO x together with LDH as a whole proved to be effective in catalyzing the transfer hydrogenation reaction and the support LDH imparted basic catalytic function to the composite realizing the aldol reaction in the absence of a homogeneous base.
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DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Yang Zhou,Lu Li,Lijun Jin,Jian Zhou,Zhiwei Shi,Yang Li,Haoquan Hu
Coal pyrolysis is generally considered to initiate by cleavage of weak covalent bonds bridged between aromatic rings. The C–C covalent bonds are predominant bridged linkages among the framework of coal, which have a critical influence on coal pyrolysis reaction but lack of direct online observation. Five representative coal-related model compounds containing C–C bridged bonds, polypropylene (PP), polyvinylpyrrolidone (PVP), poly-4-vinylpyridine (P4VP), polystyrene (PS) and poly-4-vinylphenol, were selected to pyrolyze in an in-situ pyrolysis vacuum ultraviolet photoionization mass spectrometry (Py-VUV-PIMS). The soft ionized mass spectral detection can provide product distribution and evolved information of original products and intermediates, which are the key evidence to understand the initiation, recombination and reaction routes during pyrolysis process. Online analysis of pyrolysis reaction was found to be priority with cracking of C–C bond in the five polymer samples, and homologous free radicals and original products, which mainly include monomers, dimers and their alkyl and alkenyl radicals, were detected. The results reveal the cleavage temperature of C–C covalent bond is deeply related to its chemical environment, and obvious conjugation effect and steric effect for the bridged linkage were observed. In addition, the effect of hydrogen bond was also observed during the pyrolysis of model compounds containing hydroxyl groups, and intramolecular or intermolecular hydrogen bonding reduced the temperature at which C–C bridged bonds break. The analogous fracture mode and pyrolysis behavior of coal-related model compounds, which are beneficial to understand the reaction route and mechanism of coal pyrolysis, were discussed based on the experimental observations and theoretical calculation.
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高影响因子
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