CATALYSIS SURVEYS FROM ASIA
·
2023
·Vol. 27
·期 4
·406-414
·
IF 3
Han Yujun,Shi Yinteng,Wang Dandan,Zhou Hantao,Chen Jixiang
Ni/ZrO 2 (Ni/Zr) and Ni/WO 3 -ZrO 2 (Ni/ x WZr, x denotes WO 3 /ZrO 2 mass ratios) were prepared by the impregnation-direct reduction method and tested for the aqueous phase hydrogenation of phenol to cyclohexanone in an autoclave reactor. It has been found that the Ni-W alloy forms in Ni/ x WZr, and a charge transfer occurs from Ni to W. The presence of W species promotes the Ni dispersion and increases the amounts of acid sites and spilt-over hydrogen species. This leads to higher hydrogenation and direct deoxygenation activity of Ni/ x WZr than that of Ni/Zr. In addition, the W 6+ and W 4+ species, acted as Lewis acidic sites, may stabilize cyclohexanone and the hydrogenation of cyclohexanone to cyclohexanol is inhibited. Under suitable condition, the phenol conversion and the cyclohexanone selectivity reach 93.1 and 90.6% on Ni/0.8WZr, respectively.
研究领域:
催化
·
化学反应工程
·
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2023
·
IF 5.2
Ronglin Zhao,Yaqiang Dong,Shouding Wu,Xubin Li,Zhonghao Liu,Xingjie Jia,Xincai Liu,Hang Wu,Wei Gao,Aina He,Jiawei Li
The insulation coating plays a crucial role in minimizing core loss ( P cv ) in soft magnetic powder cores (SMPCs). In this work, we prepared ZrO 2 coating layer on FeSiBNbCu spherical powder by the hydrolysis-precipitation method and investigated the magnetic properties of the FeSiBNbCu@ZrO 2 nanocrystalline SMPCs. ZrO 2 coating layer were successfully fabricated on the powder by adding a proper amount of K 2 ZrF 6 in alkaline ethyl alcohol solution. The micromorphology and chemical structure of the ZrO 2 coating layer on the surface of FeSiBNbCu nanocrystalline powder, as well as the conversion mechanisms, has been investigated. The presence of the ZrO 2 coating reduces the P cv by significantly lowers eddy loss ( P e ) of the nanocrystalline SMPCs, meanwhile improves DC bias performance and slightly decreases their permeability. When the additive amount of K 2 ZrF 6 is 1.0 wt%, the nanocrystalline SMPCs has best comprehensive soft magnetic properties, including stable effective permeability ( μ e ) of 57.8 up to 1 MHz, excellent DC bias performance of 59.3 % at a bias field of 100 Oe, and the lowest P cv of 194.7 mW/cm 3 at a frequency ( f ) of 150 kHz and maximum magnetic induction ( B m ) of 50 mT.
研究领域:
材料科学
·
电气工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2015
·
IF 2.79
Yane Zheng,Kongzhai Li,Hua Wang,Xing Zhu,Yonggang Wei,Min Zheng,Yuhao Wang
Chemical-looping reforming of methane (CLRM) offers a potentially effective approach for the coproduction of syngas and pure hydrogen. Macroporous CeO2–ZrO2 solid solutions with different pore sizes were prepared as oxygen carriers for the CLRM system. The physical and chemical properties of the oxygen carriers were characterized by the techniques of scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), X-ray powder diffraction (XRD), N2 adsorption–desorption, Raman spectra, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), and temperature-programmed oxidation (TPO). The relationship among the structural features, the concentration of oxygen defect, and the oxygen mobility of the macroporous CeO2–ZrO2 solid solutions and the nonporous sample were also discussed. It is found that the specific surface area and oxygen mobility of such oxides are closed correlated to their performance for the CLRM process. Compared with the nonporous sample, the macroporous CeO2–ZrO2 solid solutions own lower specific surface area and better oxygen mobility due to the relatively high concentration of the oxygen vacancy. This allows such oxides to own both high conversion and selectivity for the oxidation of methane to syngas using a chemical-looping concept. The presence of the macroporous structure also improves the reoxidation rate and hydrogen yield (the hydrogen yield increased by 50%) in the water splitting step. This can be attributed to the abundant channels in the materials, which may improve the dynamic conditions of the gas–solid reactions, resulting in relatively high utilization rate of oxygen carriers. The pore size also affects the activity of the macroporous oxygen carriers. The increase of the pore size slightly reduces the reactivity of the oxygen carrier due to partial collapse of the macroporous structure. The macroporous Ce–Zr-100 oxygen carrier with a pore size of 100 nm exhibits excellent activity and stability in the coproduction of pure hydrogen and high-quality syngas, even after 40 times successive redox cycles.
研究领域:
能源材料学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2022
·
IF 4.458
Wei Dang,Bowen Wang,Zhuoli Xu,Xinyuan Zhang,Fuping Li,Kang Zhao,Xu Hu,Yufei Tang
ZrO 2 nanofiber aerogels with carbon as fiber junction were fabricated by freeze drying. The effects of resorcinol-formaldehyde (RF) content and fiber content on the pore structure , thermal property and compressive property of ZrO 2 /C nanofiber aerogels were systematically investigated. ZrO 2 /C nanofiber aerogels have ultra-high porosity above 99.4%, and possess hierarchical pore structure with honeycomb pores in the micro-scale and minor pores in the nano-scale. Both RF content and fiber content have effects on the porosity, thermal conductivity and plateau stress of ZrO 2 /C nanofiber aerogels. Thermal conductivity is in the range of 0.0332–0.036 W·m −1 ·K −1 . With the increase in RF content or fiber content, both thermal conductivity and plateau stress increase. The thermal transfer mode and compressive deformation mode were analyzed. Fiber junctions play a significant role during the thermal transfer and compression of ZrO 2 /C nanofiber aerogels.
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 17
·7957-7960
·
IF 3.3
Zhicheng Luo,Zhiguo Zhu,Lupeng Han,Rui Xiao,Dawang Chu
WOx/ZrO2 is effective in the hydrogenolysis of cellulose to C3 products but the active sites on the W–Zr interfaces are hardly controlled. Herein, we prepared WOx/ZrO2 catalysts with active WOx species by simply varying the reduction temperatures, which selectively achieved C3 alcohol formation. A series of characterizations showed that increased reduction temperatures (400–600 °C) led to the formation of more dispersed WOx, while higher reduction temperatures (>600 °C) contributed to producing aggregated WO3 and W2C. At 600 °C, the dispersity of WOx peaked with a W5+/∑Wn+ ratio of 19%, providing abundant Lewis acid sites and oxygen vacancies (Vo), which were the active sites for glucose isomerization to fructose and C–C cleavage of fructose. A selectivity of 48% for C3 alcohols was obtained over the optimized WOx/ZrO2(600 °C) + Ru/AC catalyst.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2024
·Vol. 55
·期 5
·3995-4000
·
IF 2.4
Chen Angran,Zhang Yanyun,Coetsee Theresa,Kaldre Imants,Wang Cong
EH36-shipbuilding steel has been welded by CaF 2 -ZrO 2 fluxes with designed ZrO 2 additions. Possible chemical and electrochemical reactions have been postulated to analyze alloying element transfer behaviors. The decomposition of ZrO 2 during SAW has been validated by applying the gas–slag–metal equilibrium model and the O supply capacity of ZrO 2 has been quantified. For the entire compositional range, O content has been controlled within a well-maintained range from 220 to 400 ppm, and the transferred quantity of Zr content reaches to the maximum value of 120 ppm. It is further demonstrated that ZrO 2 addition incurs appreciable Si loss within the weld metal.
研究领域:
材料科学
·
焊接工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2024
·Vol. 11
·期 7
·076520
·
IF 1.8
Yuanhang Fang,Tingbian Zhan,Xiaojun Li,Changyou Xie,Xinggao Zhang,Weizhan Wang,Xiansong Jiang
A W-Zr alloy doped with ceramic powder W54.5Zr35-xNi6.7Fe3.3Mo0.5 (ZrO2) x was prepared by powder metallurgy. The effects of the ceramic content on the dynamic and static compressive mechanical behavior and energy release properties of the alloy were studied. The results showed that the addition of ceramics enhanced the energy release characteristics of the W-Zr alloy, and made the alloy break more thoroughly and the fragment cloud distribute evenly. The reaction delay time was shorter and the energy release reaction was more complete. However, the maximum temperature of the alloy reaction decreased. In addition, the addition of ceramics improves the mechanical properties of the material, and its compressive strength is much higher than that of traditional W-Zr alloys.(ZrO2)1 exhibited good mechanical behavior and energy release characteristics. The aftereffect damage performance was further verified using a ballistic gun experiment. Ballistic gun test results showed that (ZrO2) 1 can penetrate A92124 aluminum targets with a thickness of 2 mm at a speed of 809.3 m s−1 and ignite post-target absorbent cotton, with both penetration and post-target damage capabilities.
研究领域:
材料科学
·
力学
·
能源材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Yefeng Feng,Peiyao Chen,Bingshuang Mao,Maolin Bo,Qihuang Deng
Ultrahigh dielectric constant is obtained in polymer/MXene composites due to percolation . However, huge dielectric loss is triggered owing to high leakage current . In this work, hybrid filler consisting of Ti 2 C MXene and ZrO 2 was prepared for coordinating high dielectric constant and low dielectric loss in composites. Instead of Ti 2 C percolation, Ti 2 C/ZrO 2 interface effect mildly increased dielectric constant. Ultrahigh insulation and large aspect ratio of ZrO 2 fibers significantly reduced dielectric loss. Binary polymer/Ti 2 C and ternary polymer/Ti 2 C-ZrO 2 composites were fabricated, and better overall electric traits in ternary system were found. Ti 2 C/ZrO 2 interface effect was studied using density functional theory (DFT) calculations. Ternary composite with 12 wt% filler exhibited high dielectric constant of ~40, low dielectric loss of ~0.09 at 100 Hz and high breakdown strength of ~155 MV m −1 . This work might impulse fabrication of MXene-based hybrid fillers for dielectrics.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Qin Sun,Ludong Yang,Wanchun Yang,Hongjun Ji,Mingyu Li,Yufeng Li
Ceramics and metal joinings have been widely employed in aerospace, dental implants , and the electronic packaging industry for fabricating multifunctional components. In this study, the 35Bi 2 O 3 -50B 2 O 3 -15ZnO (mol.%) glass has been employed for joining the ZrO 2 ceramic and Ti-6Al-4V alloy. The effect of brazing temperature on the microstructure evolution, mechanical properties , and bonding mechanism of brazed joints has been analyzed. The microstructure of the ZrO 2 /glass/Ti-6Al-4V joints and the content of Bi 4 B 2 O 9 , Bi 2 O 3 and Bi 24 B 2 O 39 precipitated crystals in glass were found to be dependent on the brazing temperature. The reaction product of Bi 4 Ti 3 O 12 was identified in the glass/Ti-6Al-4V interface because of the chemical reaction between the oxidized layer of Ti-6Al-4V alloy and glass. A maximum shear strength as high as 48.8 ± 5.2 MPa was obtained. Our work, thus, demonstrates that the 35Bi 2 O 3 -50B 2 O 3 -15ZnO glass is an effective bonding material for joining ZrO 2 ceramic and Ti-6Al-4V alloy under low temperature in an ambient atmosphere.
研究领域:
材料科学
·
焊接工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Wangchang Geng,Pengfei Song,Xinrou Cao,Libing Duan
Metal oxides derived from metal-organic frameworks (MOFs) can maintain the porosity and unique structure of MOFs, giving them significant development potential in the field of gas sensing. In this study, bimetallic Ni/Zr-MOFs solid microspheres were synthesized via the solvothermal method, and NiO/ZrO 2 composites with p-p heterostructure were further prepared through an annealing process. The morphology, structure, specific surface area, and pore size of NiO/ZrO 2 composites were analyzed using a series of characterization techniques. The gas sensing performance study showed that the NiO/ZrO 2 -2 sensor exhibited higher response (32.3–100 ppm), lower detection limit (7.2 ppb), shorter response/recovery time (55 s/83 s), and excellent repeatability to triethylamine gas at the operating temperature of 240 ℃. Additionally, within a specific range (1–200 ppm), a strong linear relationship was observed between the response value and the gas concentration for the NiO/ZrO 2 -2 sensor (R 2 =0.9588). This study is expected to provide a valuable reference for designing high-performance triethylamine sensors.
研究领域:
材料科学
·
化学传感器
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2021
·
IF 8.001
Hui Li,Yongbo Wang,Xiaoling Ma,Min Guo,Yan Li,Guoning Li,Ping Cui,Shoujun Zhou,Mingzhi Yu
Ca 2+ ion leaching and poor pore structure are obstacles of CaO for biodiesel production . To this end, a typical Zr–based metal organic framework, UiO–66(Zr) is adopted to support calcium acetate to prepare CaO/ZrO 2 catalyst. For comparison, catalyst precursor is activated in nitrogen (UCN) and air (UCA) atmosphere, respectively. Preparation factors including calcium acetate addition and activation temperature are evaluated. Moreover, effects of transesterification parameters on oil conversion are investigated and the optimized parameters are further used to examine catalyst reusability . Meanwhile, catalysts are characterized with TG, XRD, XPS , FTIR, Hammett indicator titration, N 2 adsorption and desorption. Results reveal UCN calcined at 650 °C (UCN650) and UCA calcined at 700 °C (UCA700) separately exhibits the best catalytic performance. The maximum conversion of 96.99% is achieved by UCN650 with catalyst amount of 6 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min. Even after being used 3 cycles, conversion of 92.76% is still achieved by UCN650. By contrast, UCA700 shows lower conversion of 92.94% at the first cycle with catalyst amount of 8 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min.
研究领域:
催化化学
·
材料科学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 22
·期 2
·465-471
·
IF 1.108
Liu Shu-Cheng,Yue Zi-Feng,Liu Yi
Mesoporous carbon–ZrO 2 (MCZ) composites are prepared using a simple thermal conversion of metal–organic frameworks (MOFs). By choosing a zirconium based MOFs, called UiO-66, as both the Zr and C precursor and the porous template, porous carbon–ZrO 2 hybrid materials are formed by carbonizing UiO-66 at 600 °C in an inert atmosphere. The structure, morphology, and porosity of the products were studied using powder X-ray diffraction, transmission electron microscopy, thermogravimetry, and the BET surface area method. The obtained MCZ materials exhibit a relatively high specific surface area of ~136 m 2 g −1 , a large pore size, and pore volumes of ~9.6 nm and ~0.33 cm −3 g −1 , respectively. The results also indicate that the MCZ materials have a good capacity to adsorb Congo red from an aqueous solution.
研究领域:
材料科学
·
化学
·
环境科学
✓ 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）