RSC Advances
·
2020
·Vol. 10
·期 14
·8558-8567
·
IF 3.119
Jindong Wang,Wenzhi Li,Huizhen Wang,Ajibola Temitope Ogunbiyi,Xiaomeng Dou,Qiaozhi Ma
To improve the utilization of lignin, much effort has been devoted to lignin depolymerization with the aim to decrease waste and enhance profitability. Here, a dual property (acid and base) catalyst, namely S2O82−–K2O/TiO2, was carefully researched. Upon loading S2O82− and K2O onto TiO2, acid and base sites emerged, and S2O82− and K2O mutually enhanced the acid and base strengths of the catalyst enormously; this indeed facilitated lignin depolymerization. Under appropriate conditions, the yields of liquid product, petroleum ether soluble (PE-soluble) product and total monomer products were 83.76%, 50.4% and 28.96%, respectively. The constituents of the PE-soluble fraction, which are mainly monomers and dimers, can be used as liquid fuels or additives. In addition, after the catalyst was modified by Ni, better results were obtained. Surprisingly, it was found that the Ni enhanced not only the hydrogenation capacity but also the acidity. The highest high heating value (HHV) of the liquid product (33.6 MJ kg−1) was obtained, and the yield of PE-soluble product increased from 50.4 to 56.4%. The product can be utilized as a fuel additive or be converted to bio-fuel. This catalysis system has significant potential in the conversion of lignin to bio-fuel.
研究领域:
化学工程
·
可再生能源
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Huahua Zhao,Huanling Song,Fangyuan Wang,Zhichao Miao,Lingjun Chou
In the present work, a new strategy was developed to fabricate strong basicity on mesoporous zirconia by in-situ preservation of carbon species originated from organic template during the thermal treatment of mesoporous ZrO 2 . The carbon species was maintained on mesoporous zirconia by calcination in N 2 prior to the introduction of base precursor KNO 3 . The decomposition temperature of KNO 3 to strongly basic site K 2 O was significantly reduced from higher than 650℃ to about 400℃ in the presence of carbon species, which fascinatingly converted the endothermic decomposition reaction to exothermic process. More importantly, the tetragonal ZrO 2 support with excellent mesostructure was well stabilized by the carbon species after introduction of K species. Therefore, K 2 O supported on mesoporous tetragonal zirconia (K 2 O/M-ZrO 2 -C) were successfully fabricated. The resultant mesoporous basic material presented good activity in the synthesis of dimethyl carbonate (DMC) and the DMC yield was 60.0 %, apparently higher than that (18.1 %) of the catalyst prepared without preserving carbon species (K 2 O/M-ZrO 2 ). The strong basicity and the uniform mesopores of the catalyst were suggested to be contributed to the high activity. The obtained results will provide some fundamental understanding and guidance for rational catalyst design.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·794
·
IF 2.7
Wang Xuekai,Cao Yongze,Yan Xianglan,Li Lei,Zhang Xizhen,Zhang Jinsu,Chen Baojiu
17K 2 O–33SnO–50P 2 O 5 –xMnCl 2 glasses with x = 0, 0.6, 1.2, 1.8, 2.4, 3.0 were made using melt quenching at 500 °C low temperature. The structure and photoluminescence properties of these glasses were investigated, and the water resistance was evaluated. The experimental results show that the effectively energy transfer from Sn 2+ to Mn 2+ occurs, and when Mn 2+ doping at 3.0, the energy transfer efficiency reaches 74%. Under 340 nm excitation, the emission wavelength is in the range of 500–800 nm, covering the absorption wavelength of chlorophyll P R and P FR , which indicates that the low temperature glasses can be used for plant cultivation. This glass material was immersed in water for 24 h, and the luminescence intensity decreases 10%. This indicates that the glass material has certain waterproof property.
研究领域:
材料科学
·
农业光学
·
无机非金属材料
·
光生物学
·
功能玻璃
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jian Bao,Jialun Du,Lintao Liu,Haitao Wu,Yuanyuan Zhou,Zhenxing Yue
A new type of microwave dielectric ceramics with low dielectric loss was fabricated through a traditional solid-phase method. X-ray diffraction and density tests showed that KSrPO 4 ceramics with a single orthorhombic phase could be synthesized and densified at 950 °C, and the crystal structure of KSrPO 4 was further confirmed by Rietveld refinement analysis. The densification temperature of KSrPO 4 was lower than 961 °C, indicating the ceramics could be used in LTCC devices. Additionally, based on the complex chemical bond theory, some internal parameters of KSrPO 4 ceramics were calculated and the effects of these parameters on the properties of KSrPO 4 were systematically analyzed for the first time. Furthermore, the composite dielectric constant and loss of KSrPO 4 ceramics were analyzed by infrared reflectance spectroscopy, and the theoretical loss and the actual loss were compared. Finally, a vector network analyzer was employed to measure the microwave dielectric properties of all samples. The results showed that KSrPO 4 sintered at 950 °C obtain the best microwave dielectric properties, including ε r = 7.85, Q·f = 34,527 GHz (at 10.43 GHz) and τ f = −14.82 ppm/°C.
研究领域:
材料科学
·
电气工程
·
陶瓷
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Yongsheng Yu,Saibo Wang,Yiyan Xu,Pengzhen Wang,Yunxiao Zhao,Jinghan Wang,Zhaoli Yan,Qiangshan Jing
Glass-ceramics with α-cordierite as the primary crystalline phase were prepared via solid-state sintering with varying K 2 O additions, utilizing perlite tailings as the starting material. The effects of sintering temperature and K 2 O addition on the glass structure, crystallization behavior, microstructure, properties and crystallization kinetics were systematically investigated. The results indicated that an appropriate addition of K 2 O could prevent the formation of μ-cordierite intermediate phase and promote the direct precipitation of α-cordierite, thereby effectively shortening the overall crystallization pathway. This addition also lowered the densification temperature of the glass-ceramics and improved their mechanical and dielectric properties. Crystallization kinetics analysis revealed that K 2 O addition significantly reduced the crystallization activation energy of α-cordierite, while remaining the bulk nucleation and one-dimensional crystal growth mechanism. The α-cordierite glass-ceramics with 0.7 wt% K 2 O addition sintered at 850 °C exhibited the optimal comprehensive properties: high flexural strength of 145.7 MPa, low dielectric loss of 1.80 × 10 −2 at 10 MHz, and suitable coefficient of thermal expansion of 3.71 × 10 −6 K −1 . These properties highlight the potential of this glass-ceramic as a promising candidate for low-cost LTCC substrate materials.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 22
·26655-26665
·
IF 2.478
Yang Chengyu,Li Junkai,Lu Yang,Shan Yiting,Xian Qianqian,Zhou Hongqing
CaO-B 2 O 3 -SiO 2 (CBS) glass ceramic with various glass network modifiers were synthesized to develop a kind of material sintered at low temperature for multi-layer ceramic substrates. The influence of double alkali metal oxides (Na 2 O and K 2 O) on sintering characteristics, microstructures and dielectric properties of CBS glass ceramic were investigated. XRD analysis showed that the major crystalline phase was β-CaSiO 3 and CaB 2 O 4 , and the strength of the peak increased with the addition of network modifiers. DSC curve revealed that the process of crystallization and softening were obviously affected. SEM photographs exhibited that the microstructures were composed of amorphous phases, pores and crystalline phases. FTIR showed that the additives changed the continuity of CBS glass structure. An appropriate amount of Na 2 O and K 2 O additives could significantly improve the sintering characteristics and dielectric properties. CBS samples with 1.5 wt% (Na 2 O + K 2 O) sintered at 850 °C for 15 min presented the best performances with the bulk density of 2.53 g/cm 3 , ε r = 5.94 and tan δ = 1.22 × 10 −3 at 10 GHz.
研究领域:
材料科学
·
陶瓷学
·
电子学
✓ 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）