Journal of Materials Research and Technology-JMR&T
·
2025
·
IF 6.6
Yuanming Zhou,Zhenxiao Tang,Ruizhi Liu,Zhe Zhou,Maozhong Yi,Ke Peng
To further enhance the ablation resistance of C/C composites, solid solution ceramic Ta 0.2 Zr 0.8 C was used to replace traditional ultra-high-temperature ceramic carbides for matrix modification of C/C composites. The C/C-Ta 0.2 Zr 0.8 C-SiC composite was fabricated by a high-solid-loading slurry impregnation combined with the precursor infiltration and pyrolysis process. The comparative samples of C/C-ZrC-SiC and C/C-TaC-SiC were also prepared using these same technologies. The microstructure, flexural properties, and ablation performance of the composite were investigated. Results showed that the C/C-Ta 0.2 Zr 0.8 C-SiC exhibited excellent overall flexural properties. During the ablation test under an oxyacetylene flame with high heat flux, the ablation resistance of C/C-Ta 0.2 Zr 0.8 C-SiC improved with prolonged ablation time, reaching mass and linear ablation rates of 0.67 mg/s and 0.18 μm/s after 120 s of ablation. Compared to the C/C-ZrC-SiC and C/C-TaC-SiC, the mass ablation rate of the composite was reduced by 49.24% and 68.70%, and the linear ablation rate was reduced by 97.22% and 97.71%, respectively. The enhanced ablation resistance was primarily attributed to the formation of the Ta-Zr-O oxide layer, composed of TaZr 2.75 O 8 , ZrO 2 , and Ta 2 O 5 , on the composites surface. In the oxide layer, the Ta-rich oxides served as a binder, filling gaps in the interface. Meanwhile, the Zr-rich oxides formed the skeleton that pinned the molten liquid oxides. The combined effects of Ta-rich and Zr-rich oxides made the Ta-Zr-O oxide layer more compact and strongly bonded to the matrix.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·Vol. 34
·期 44
·2405922
·
IF 18.5
Minmin Ma,Ran Wang,Li Shi,Ronghua Li,Jie Huang,Zhuo Li,Peng Li,Elena Yu. Konysheva,Yanbo Li,Gang Liu,Xiaoxiang Xu
Photocatalytic carbon-carbon (C─C) coupling of benzyl alcohol is a promising means to coproduce the value-added chemicals with H 2 but is generally subject to low efficiency in terms of photon utilization. Here, efficient benzyl alcohol C─C coupling is achieved over Zn 2 In 2 S 5 containing a tunable content of Zn vacancies ( V Zn ). The V Zn tends to form shallow defect states below the conduction band that can expedite photocarrier separation by collecting the photo-generated electrons. The V Zn -collected electrons are essential for a high selectivity of the C─C coupling reactions because they enable a fast elimination of the byproduct benzaldehyde by catalyzing its reduction back to the ketyl radicals. Under simulated sunlight, the V Zn -containing Zn 2 In 2 S 5 accomplishes ≈100% conversion of benzyl alcohol for merely 1 h and attains ≈100% selectivity for the C─C coupling compounds for 2 h, delivering an apparent quantum yield as high as 7.7% at 420 ± 20 nm. The benefits of V Zn have also been verified by the theoretical calculations that indicate reduced energy barriers for various surface reactions in the presence of V Zn . This work brings fresh mechanistic insights into the role of V Zn and can serve as a useful guideline in the design of efficient photocatalysts.
研究领域:
材料科学
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光催化化学
·
表面化学
✓ 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.
研究领域:
材料科学
·
电化学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
APPLIED COMPOSITE MATERIALS
·
2022
·Vol. 29
·期 6
·2147-2163
·
IF 2.368
Wang Pei,Guo Yonggang,Du Sanming,Jia Yunchao,Zhang Hongbo,Yin Jian
Taking the advantages of porous ceramic (C/C-SiC composite) and transpiration cooling (Copper alloy), C/C-SiC-Cu composite was fabricated to attain a novel anti-ablation material for high temperature structure application of aerospace systems, via chemical vapor deposition and infiltration technologies. The effects of SiC content on microstructure, thermal conductivity, mechanical and ablation properties of C/C-SiC-Cu composite were investigated. As the SiC content increases from 0 vol% to 25.12 vol%, thermal conductivity, flexural strength and ablation resistance are improved by 84.99%, 78.76% and 53.68%, respectively. Thermal conductivity and thermal diffusivity exhibit proportional linear correlation with SiC content. The high SiC content could shorten the yield stage and increase the breaking strength during the flexural fracture process. When the SiC content is 25.12 vol%, the formation continuous and compact anti-ablation (SiO 2 ) layer is formed by oxidizing and melting fluidity processes during oxyacetylene ablation test, and the protective layer covers the ablation surface and slows down the oxidative ablation, which combines with the transpiration cooling effect of copper alloy to further improve ablation resistance of C/C-SiC-Cu composite.
研究领域:
航空航天材料科学
·
高温结构材料
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yunjia Wei,Qi Hao,Xingce Fan,Mingze Li,Lei Yao,Guoqun Li,Xing Zhao,Hao Huang,Teng Qiu
The implementation of plasmonic materials in heterogeneous catalysis was limited due to the lack of experimental access in managing the plasmonic hot carriers. Herein, we propose a liquid-state surface-enhanced Raman scattering (SERS) technique to manipulate and visualize heterogeneous photocatalysis with transparent plasmonic chips. The liquid-state measurement conquers the difficulties that arise from the plasmon-induced thermal effects, and thus the plasmon based strategies can be extended to investigate a wider range of catalytic reactions. We demonstrated the selection of reaction products by modulating the plasmonic hot carriers and explored the mechanisms in several typical C–C coupling reactions with 4-bromothiophenol (4-BTP) as reactants. The real-time experimental results suggest brand new mechanisms of the formation of C–C bonds on plasmonic metal nanoparticles (NPs): the residue of 4-BTP, but not thiophenol (TP), is responsible for the C–C coupling. Furthermore, this technique was extended to study the evolution of the Suzuki–Miyaura reaction on nonplasmonic palladium metals by establishing the charge transfer channels between palladium and Au NPs. The cleavage and formation of chemical bonds in each individual reaction step were discerned, and the corresponding working mechanisms were clarified.
研究领域:
催化化学
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材料科学
·
光化学
✓ 已验证
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
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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
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
CATALYSIS TODAY
·
2014
·
IF 3.309
Junjie Zhang,Fang Lu,Weiqiang Yu,Jiazhi Chen,Shuai Chen,Jin Gao,Jie Xu
The use of high pressure fossil derived hydrogen limits the commercial prospects of transforming sorbitol to glycols. Ni–Re/C catalyst which was developed in this study demonstrated high selectivity toward hydrogenative cleavage of C2–C3 and C3–C4 bonds of sorbitol to produce glycols under 1 MPa nitrogen. Acetol which is proposed as important intermediate to explain the reaction mechanism was first detected in the sorbitol conversion reactions. Detailed investigations showed that the presence of Re could prevent the sintering of Ni particles during the reduction process and make the catalyst efficiently generate hydrogen on the active sites to selectively cleave C–C bonds in sorbitol under nitrogen atmosphere.
研究领域:
催化化学
·
绿色化学
✓ 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
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Yuanming Zhou,Shuxin Li,Shuangxing Zhu,Ruizhi Liu,Zhenxiao Tang,Maozhong Yi,Ke Peng
To investigate the influence of (Ta,Zr)C on the ablation resistance of C/C composites, C/C-(Ta 0.5 Zr 0.5 )C-SiC, C/C-(Ta 0.33 Zr 0.67 )C-SiC, and C/C-(Ta 0.2 Zr 0.8 )C-SiC were prepared with different Zr/Ta ratios through high-solid-loading slurry impregnation combined with precursor infiltration and pyrolysis. The flexural performance and ablation resistance both improved with an increasing Zr/Ta ratio. Compared to C/C-(Ta 0.5 Zr 0.5 )C-SiC and C/C-(Ta 0.33 Zr 0.67 )C-SiC, the flexural strength of C/C-(Ta 0.2 Zr 0.8 )C-SiC increased by 74.17 % and 24.29 %, respectively. The mass ablation rate was reduced by 74.33 % and 81.02 %, while the linear ablation rate was reduced by 98.60 % and 97.65 % after 120 s of ablation, respectively. The variations in Zr/Ta ratios affected the formation, integrity, and performance of the microstructure, which was composed of a Zr-rich oxide skeleton combined with Ta-rich oxide binder within the Ta-Zr-O oxide layer on the composite surface, ultimately enhancing the overall ablation resistance of these composites.
研究领域:
材料科学
·
航空航天工程
✓ 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）