Molecular Catalysis
·
2017
·
IF 0
Zhanao Lv,Haibin Wang,Zhuqi Chen,Shuhua Zou,Shuaishuai Zhu,Chenlin Lou,Guochuan Yin
Dioxygen activation as the solely terminal oxidant in organic synthesis and catalytic oxidation is particularly attractive from the point of economic and environmental view. In our previous study, we have displayed that the introducing of non-redox metal ions can sharply improve the olefin epoxidation catalyzed by ruthenium complex with PhI(OAc) 2 as the organic oxidation. Inspired by the successful strategy and dioxygen activation, in this study, we demonstrate an alternative protocol that adding non-redox metal ions to cis -Ru(bpy) 2 Cl 2 catalyst can remarkably improve the oxidation from Ru(II) to Ru(IV) = O with dioxygen as the oxidant and promote oxidative dehydrogenation of saturated C–C bond whereas Ru(bpy) 2 Cl 2 alone is very sluggish. Through UV–Vis, NMR, cyclic voltammogram and EPR characterization, it has been testified that oxidation from Ru(II) to Ru(IV) = O can be realized under the condition of 1 atm of dioxygen and 323 K within 25 min while extreme tough condition of 20 atm of dioxygen, 343 K and 8 h is necessary for Ru(bpy) 2 Cl 2 alone. Combined the reaction data with characterization results, an adduct of Ru(IV) = O/Sc(III) is proposed as the key active species to improve the catalytic efficiency. The activity improvement in oxidative dehydrogenation illustrated a novel strategy of that adding non-redox metal ions to sluggish catalysts can remarkably improve its efficiency for dehydrogenation of saturated C–C bond, especially through dioxygen as ultimate oxidant.
✓ 已验证
产品关联
DOI
Journal of the American Chemical Society
·
2024
·
IF 14.4
Ernest Pahuyo Delmo,Yian Wang,Yihua Song,Shangqian Zhu,Haichuan Zhang,Hongming Xu,Tiehuai Li,Juhee Jang,Yongjun Kwon,Yinuo Wang,Minhua Shao
The reaction mechanism of CO2 electroreduction on oxide-derived copper has not yet been unraveled even though high C2+ Faradaic efficiencies are commonly observed on these surfaces. In this study, we aim to explore the effects of copper anodization on the adsorption of various CO2RR intermediates using in situ surface-enhanced infrared absorption spectroscopy (SEIRAS) on metallic and mildly anodized copper thin films. The in situ SEIRAS results show that the preoxidation process can significantly improve the overall CO2 reduction activity by (1) enhancing CO2 activation, (2) increasing CO uptake, and (3) promoting C–C coupling. First, the strong *COO– redshift indicates that the preoxidation process significantly enhances the first elementary step of CO2 adsorption and activation. The rapid uptake of adsorbed *COatop also illustrates how a high *CO coverage can be achieved in oxide-derived copper electrocatalysts. Finally, for the first time, we observed the formation of the *COCHO dimer on the anodized copper thin film. Using DFT calculations, we show how the presence of subsurface oxygen within the Cu lattice can improve the thermodynamics of C2 product formation via the coupling of adsorbed *CO and *CHO intermediates. This study advances our understanding of the role of surface and subsurface conditions in improving the catalytic reaction kinetics and product selectivity of CO2 reduction.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·Vol. 137
·期 4
·1911-1925
·
IF 1.7
Song Linyan,Nie Genkuo,Chen Xiulei,Wang Hongyu,Liu Shiwei,Yu Hailong,Liu Xuguang,Yang Guihua,Yu Shitao
The multifunctional groups of 5-hydroxymethylfurfural (5-HMF) make it could extend carbon chain by different C–C coupling reactions and extensively applied in the bio-jet fuel synthesis. Herein, one-pot reaction of lignocellulose derived chemicals with 5-HMF was studied by experimental and density functional theory (DFT) methods. The kinetic models of products were established and the apparent activation energies of the products by C–C coupling reaction of phenol, anisole, guaiacol, cyclohexanone and acetone with 5-HMF on Hβ were 95.3 kJ/mol, 104.8 kJ/mol, 90.4 kJ/mol, 90.0 kJ/mol and 112.2 kJ/mol, indicating these reactions centering on 5-HMF competitive intensively. Then the effects of the catalysis were analyzed by applying commercial catalysis to the mixed coupling reaction of 5-HMF. It was found that Brønsted acid is more favorable to alkylation reaction, and Lewis acid is more beneficial to aldol condensation reaction. By Fukui function, due to the nucleophilic index of cyclohexanone (2.74 eV) is higher than that (2.48 eV) of acetone, and the Mulliken electronegativity (3.43 eV) is weaker than that (3.55 eV) of acetone, cyclohexanone is more conducive than acetone to the aldol condensation reaction. This work provides data reference for product regulation in the bio-jet fuel synthesis.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Wei Wei,Zhenyao Li,Jitao Shang,Chenxi Xia,Xuli Hu,Yangshun Hu,Junchen Xu,Yan Zhao,Mingyue Ding
The selective electrochemical reduction of CO to valuable multi-carbon (C 2 + ) products is a key strategy for mitigating global warming and addressing the energy crisis. Nevertheless, the activity and selectivity of CO-to-C 2+ products conversion remain low due to the lack of effective catalysts. In this study, bimetallic CuPd was grown in situ on Cu nanoparticles via a seed-mediated approach, constructing a stable CuPd/Cu interface for the CO reduction reaction (CORR). The CuPd alloy promotes CO adsorption and hydrogenation, resulting in abundant and stable *COH intermediates over catalytic sites. Consequently, a stable asymmetric coupling is established at the CuPd/Cu interface, lowering the reaction energy barrier and facilitating C-C coupling. A high acetate selectivity of 49 % was achieved at –1.0 V versus the reversible hydrogen electrode (RHE) with a current density of 349 mA/cm². This study highlights the critical role of constructing CuPd/Cu asymmetric sites for C–C coupling, paving the way for designing highly selective catalysts that enhance C 2+ product formation and acetate production.
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Zhixiu Yang,Xiaoxuan Guo,Yong Chen,Lijing Gao,Ruiping Wei,Guomin Xiao
Modulating the surface microenvironment is crucial in strengthening C C coupling, leading to increasing selectivity in the production of multi-carbon (C 2+ ) products during CO 2 electroreduction. Herein, we have concentrated on investigating how to control the effect of surface distribution of active components of a series of Ag-decorated CuO , denoted as xAg/yCuO. These catalysts with similar chemical elements and morphology are designed, but they exhibit different selectivity in the CO 2 electroreduction process. As a result, the Ag particles in 3Ag/CuO aggregates, while the Ag in 2Ag/2CuO and Ag/3CuO is uniformly distributed on the flower-like CuO nanosphere . Besides, 3Ag/CuO has the highest Faraday efficiency (FE) of CO with a value of 30.9 % at 0.8 V vs. RHE, demonstrating rich-Ag catalysts are beneficial to produce CO. 2Ag/2CuO shows excellent FE C2H4 of 51.4 % at -1.2 V vs. RHE due to the highly dispersed distribution of Ag on the flower-like CuO and higher vacancy O. Ag/3CuO exhibits higher FE H2 compared to other catalysts across a wide potential range, and its minimal impedance is attributed to its exceptional performance in the hydrogen evolution reaction . The proposed reaction pathway for the most effective catalysts 2Ag/2CuO, as determined by in-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), involves the following steps: CO 2 →*CO 2 − → *COOH → *CO→ *CHO→ *OCHCHO→ *OCHCH 2 → C 2 H 4 . These findings demonstrate that controlling the surface structure can influence the local environment to enhance the efficiency of CO 2 electroreduction.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2025
·
IF 6.6
Yuanming Zhou,Mingyang Li,Shuxin Li,Shuangxing Zhu,Ruizhi Liu,Maozhong Yi,Ke Peng
The oxide layer that forms on the surface of C/C composites matrix-modified with multiphase ultra-high temperature ceramics is generally loose and poorly bonded, limiting its effectiveness in enhancing the ablation resistance of C/C composites. In this study, C/C composites were matrix-modified using solid solution ceramic TaZr 2 C 3 -SiC and multiphase ceramic TaC-2ZrC-SiC, both with the same Zr/Ta ratio. The C/C-TaZr 2 C 3 -SiC and comparative sample C/C-TaC-2ZrC-SiC composites were prepared through a high-solid-loading slurry impregnation method combined with a precursor infiltration and pyrolysis process. The flexural properties were evaluated, and ablation tests were conducted under an oxyacetylene flame. Compared to C/C-TaC-2ZrC-SiC, the C/C-TaZr 2 C 3 -SiC sample exhibited superior flexural properties and ablation resistance. The flexural strength, elastic modulus, and fracture toughness improved by 10.80%, 29.75%, and 37.67%, respectively. The mass and linear ablation rates were reduced by up to 85.49% and 77.26%, respectively. The superior ablation resistance of C/C-TaZr 2 C 3 -SiC was attributed to the formation of the anti-ablation microstructure composed of the Ta-rich oxide binder phase and Zr-rich oxide skeleton phase in the Ta-Zr-O oxide layer. The microstructure enhanced the viscosity of the oxides and strengthened their interfacial bonding, effectively suppressing the splashing and consumption of surface oxides under high heat flux while preventing their accumulation in the brim ablation region. The oxide layer was more compact and tightly bonded to the composite surface, providing the composites with significantly improved ablation protection. These findings provide a novel and effective approach for further improving the ablation resistance of C/C composites.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Huimin Li,Zhe Sun,Chenlong Dong,Xueli Zhang,Chengkun Lei,Baobao Jin,Qianqian Shen,Husheng Jia,Jinbo Xue
Photocatalytic non-oxidative coupling of methane is an attractive strategy for CH 4 to C 2 conversion, how to facilitate the photogenerated charge separation and accelerate the C–C coupling to promote the reaction kinetics remains a great challenge. Herein, a symbiotic r-Fe 2 O 3 /NiO heterostructure with robust interfaces is constructed in situ. The coherent interface not only provides unique Ni–O–Fe asymmetric sites, but also achieves the separation and transport of photogenerated charge. The unbalanced charge density distribution of two adjacent methyl or methylene at the Ni–O–Fe asymmetric site alleviates the dipole repulsion of the C–C coupling, and promotes C–C coupling to form C 2 hydrocarbons. Under visible light irradiation, the optimal r-Fe 2 O 3 /NiO performs a brilliant C 2 activity up to 71.00 μmol g −1 h −1 , and the C 2 H 4 yield can reach a high value of 40.46 μmol g −1 h −1 and the selectivity of 56.98 %. This work provides new insights into the coupling of C–C to generate C 2 hydrocarbons.
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Zupeng Chen,Yongqi Zhuang,Yuguo Dong,Yanmei Zheng,Wenjun Zhang,Lin Dong
Lignin, the most abundant natural aromatic polymer on Earth, offers a promising feedstock for the production of value-added aromatic products through selective C-C bond cleavage. However, achieving both high product yield and selectivity under mild conditions, such as under visible-light irradiation, remains a significant challenge. In this study, we address this issue by employing ceria (CeO2) as a support to precisely engineer the dispersion of vanadium oxide through two distinct catalyst pretreatment methods: impregnation–calcination (Im-V/CeO2) and physical mixing–calcination (Pm-V/CeO2). The results demonstrate that the Im-V/CeO2 catalyst exhibits superior performance, converting 1,2-diphenylethanol to benzaldehyde with an impressive 89% yield and 98% selectivity, while CeO2 alone yields 52% and Pm-V/CeO2 yields 45%. This enhanced performance of Im-V/CeO2 is attributed to the introduction of low-polymerized vanadium oxide (VOx) species. Unlike highly polymeric V2O5 crystals, these species facilitate the separation of photogenerated electron-hole pairs and reduce charge transfer resistance, thereby improving photocatalytic efficiency. Additionally, the polar nature of VOx species enhances the activation of lattice oxygen, creating more sites for oxygen adsorption and activation. In-depth mechanistic studies reveal that superoxide radicals play a dominant role in the C-C bond cleavage process. This innovative strategy for achieving high-efficiency photocatalytic C-C bond cleavage through the controlled dispersion of vanadium oxide on a cerium oxide support offers valuable insights for the sustainable valorization of lignin.
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2025
·Vol. 12
·期 9
·095005
·
IF 2.2
Xinfa Qiang,Xiangyu Chen,Maoheng Dong,Zi Yang,Wensu Meng,Hai Kan,Keqing Wang,Lijin Wang,Ling Wang,Chao Wu
A unique bead-chain-like SiC nanowires (SiCnws) morphology was successfully synthesized via an aerogel carbothermal reduction method. Microstructural analysis revealed that the SiC chain display diameters ranging from 100 to 200 nm, while the SiO2 bead exceed 1 μm in diameter. A SiCnws reinforced CrSi2-SiC/SiC coating was prepared on C/C composites by a two-step pack cementation. Comparative analysis revealed that SiCnws-reinforced coating exhibited better densification with lesser cracks and pores. Isothermal oxidation tests at 1773 K in static air demonstrated exceptional performance: the SiCnws-reinforced coating showed only 14.98% mass loss after 30 h, while the unreinforced coating suffered 36.53% mass loss after 14 h. XRD/SEM characterization confirmed that SiCnws enhanced structural integrity by promoting the formation of a continuous SiO2-Cr2O3 glassy layer during oxidation, while mitigating crack propagation through pinning and bridging effects.
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2025
·Vol. 22
·期 2
·e10087
·
IF 12.1
Fujian Liu,Min Li,Mengnan Liu,Yujie You,Su Liu,Qiangyu Xue,Azim Abdullaev,Yinsong Si
Flexible electromagnetic interference (EMI) shielding inorganic materials integrated with thermal management remain highly desirable for next-generation wearable electronics in protective applications. Here, a core–shell carbon@carbon/silica (C@C/SiO 2 ) composite nanofiber is fabricated via a coaxial electrospinning and subsequent carbonization. By tailoring the carbon content in the core and the carbonization temperature, the resulting C@C/SiO 2 nanofiber achieves a gradient interfacial architecture. Benefiting from the continuous C core and the groove-like C/SiO 2 shell, the C@C/SiO 2 nanofiber exhibits high flexibility, superior EMI shielding, and reliable thermal control performance. The optimized conductivity and impedance matching endow the composite membrane with an outstanding EMI shielding effectiveness of 30.8 dB and a high shielding effectiveness/thickness value of 133.7 dB mm −1 at only 0.23 mm thickness, corresponding to a shielding efficiency exceeding 99.92%. Moreover, it delivers ultrafast and stable Joule heating behavior, reaching ≈220 °C within 10 s at a low voltage of 10 V and a maximum temperature of 250 °C. Meanwhile, the membrane also maintains structural and functional stability even after 8000 bending cycles and 100 thermal shock cycles. This work provides a tunable route toward lightweight, durable, and highly efficient EMI shielding membranes for applications in flexible electronics and harsh-environment protection systems.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 6
·3243-3256
·
IF 1.843
Zhou Lin,Wang Ruo-Bing
Nitrogen doped mesoporous carbon (N-MPC)-supported monometallic and bimetallic catalysts were synthesized by using hydrothermal and impregnation method, and the catalytic activity of the catalyst to carbon–carbon bond-forming reactions (Suzuki, Heck and Sonogashira reactions) was studied. The bimetallic catalyst Pd-Ni@N-MPC with high Ni to Pd atomic ratios showed highly activity in the C–C coupling reactions of aryl halide under optimized condition. In contrast to their monometallic counterparts, such Pd-Ni@N-MPC catalyst not only show higher catalytic activity but also show more economic and stable. The catalysts were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy, which demonstrated that the Pd–Ni NPs highly dispersed and possessed uniform size.
Graphical abstract
✓ 已验证
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 194
·期 11
·4999-5016
·
IF 3.094
Ma Teng,Kong Weixi,Liu Yunting,Zhao Hao,Ouyang Yaping,Gao Jing,Zhou Liya,Jiang Yanjun
The application of immobilized enzymes in pharmaceutical and bulk chemical production has been shown to be economically viable. We demonstrate the exceptional performance of a method that immobilizes the old yellow enzyme YqjM and glucose dehydrogenase (GDH) on resin for the asymmetric hydrogenation (AH) of C = C bonds in a SpinChem reactor. When immobilized YqjM and GDH are reused 10 times, the conversion of 2-methylcyclopentenone could reach 78%. Which is because the rotor of the SpinChem reactor effectively reduces catalyst damage caused by shear force in the reaction system. When the substrate concentration is 175 mM, an 87% conversion of 2-methylcyclopentenone is obtained. The method is also observed to perform well for the AH of C = C bonds in other unsaturated carbonyl compounds with the SpinChem reactor. Thus, this method has great potential for application in the enzymatic production of chiral compounds.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）