JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Zhipin Zhu,Yuanbing Li,Shujing Li,Shiqi Li,Chen Bai,Fang Liu
ZrP 2 O 7 -based fiber composites were prepared by in situ synthesis and their microstructure, thermal conductivity, mechanical and dielectric properties were determined. The chemical reaction with BPO 4 as the phosphorus source and nano-ZrO 2 as the zirconium source was initiated at 900°C, which promotes liquid-phase sintering and reduces the sintering densification temperature of the ZrP 2 O 7 -based fiber composites by generating small ZrP 2 O 7 grains and low-melting B 2 O 3 . The lower sintering densification temperature and the appropriate amount of network formers effectively suppressed the high-temperature crystallization phenomenon of the high-silica-oxygen fibers, strengthened the interfacial bonding between the fibers and the matrix, and improved the interfacial debonding problem of the ZrP 2 O 7 -based fiber composites. It is found that the ZrP 2 O 7 -based fiber composites possess low dielectric constant, low dielectric loss, good thermal conductivity, and acceptable mechanical properties, which can meet the relevant application requirements of centimeter-wave technology.
研究领域:
材料科学
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无机化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
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IF 6.609
Bo Chen,Ruiheng Rao,Meifang Cao,Chengzhi He,Yong Qian,Xueqing Qiu,Xinping Ouyang
An imperative current challenge for the production of renewable fuels is the development of efficient catalytic hydrodeoxygenation (HDO) of phenolic-rich bio-oils into hydrocarbons. In this work, a series of bifunctional ZrP 2 O 7(x) -Ni 12 P 5 (where × represents the molar ratio of Zr/Ni in the catalysts) catalysts were prepared for HDO of lignin-derived bio-oils (LBO). The characterization results show that among these bimetallic catalysts, ZrP 2 O 7(0.4) -Ni 12 P 5 possesses the largest specific surface area, pore volume and the highest amount of acid sites (Lewis and Brønsted) due to the introduction of appropriate amount of Zr species. Meanwhile, the interaction between Ni δ+ and Zr species on its surface creates new active sites for the promotion on the hydrogen adsorption and activation, thus endowing the most excellent catalytic performance. Using the optimized catalyst of ZrP 2 O 7(0.4) -Ni 12 P 5 , 95.8% cyclohexane yield could be obtained from the HDO of guaiacol as a model compound from bio-oil under mild condition (3 MPa H 2 and 250 ℃). Moreover, 36.1% hydrocarbon yield is achieved from HDO of lignin-derived bio-oils (LBO) under the same hydrogen pressure and temperature. These findings not only open a novel avenue for designing a cost-effective metal–acid bifunctional catalyst, but also provide a viable approach for converting lignocellulosic biomass feedstocks into valuable hydrocarbons.
研究领域:
能源科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2024
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IF 5.8
Menghong Li,Hong Tang,Jiawei Li,Jiao Han,Yiming Zeng,Ping Yang,Yuanbing Li,Shiqi Li,Xinyu Fan
In this study, a two-step method combining the direct foaming process with the control of solid content and heat treatment temperature was employed to prepare ZrP 2 O 7 -CePO 4 composite porous materials with varying porosities. The results indicate that an increase in solid content and heat treatment temperature leads to a reduction in porosity and average pore size while simultaneously improving the mechanical properties. The porosities, compressive strengths , thermal conductivities , ε and Tanδ ranged from 63.2 to 85.3 vol%, 19.43 to 0.99 MPa, 0.089 to 0.088 W/(m·K), 1.64 to 2.72, and 0.88 × 10 −3 to 1.99 × 10 −3 , respectively. Electromagnetic simulations have validated that ZrP 2 O 7 -CePO 4 composite porous ceramics , when used as the core layer material for A-sandwich antenna radomes, exhibit excellent transmittance properties. This suggests the potential application of these materials for supersonic aircraft antenna radomes.
研究领域:
材料科学
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航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
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IF 5.1
Dongxia Chen,Xiaofei Yan,Mengjie Yang,Xianli Wang,Linjie Fu,Mingyu Li,Zhanjun Yu
ZrP 2 O 7 is a promising material with excellent thermal and electrical properties. However, when temperature approaches to 563 K, it undergoes a structural phase transition, which will cause large thermal stresses. When Zr is substituted by Y and Nb, a new material of (YNb) 0.2 Zr 0.6 P 2 O 7 , was successfully prepared and the phase transition of material was effectively inhibited. This new material adopts a cubic structure similar to ZrP 2 O 7 , and exhibits medium thermal expansion (α = 7.1 × 10 −6 K −1 ) in the measured range of 200–1073 K. The values of thermal conductivity from RT to 973 K are between 0.4474 W m −1 K −1 and 0.8526 W m −1 K −1 , which can be comparable to the values of traditional thermal insulation materials. The dielectric constant and dielectric loss factor at the frequencies above 1 MHz are stable and low. The electrical conductivity of the material indicates that it is electronically insulating at RT-573 K.
研究领域:
材料科学
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热力学
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电学
✓ 已验证
产品关联
DOI
高影响因子
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