APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Decun Luo,Ziyu Tang,Xiyang Yu,Tao Zhang,Chun-Ran Chang,Zhun Hu
The effect of ZrO 2 crystalline phases on Pd/ZrO 2 for catalytic combustion of toluene was investigated. It was found that Pd/t-ZrO 2 showed superior activity when the toluene concentration was lower than 2000 ppm, while Pd/m-ZrO 2 performed better with toluene concentration higher than 3000 ppm. Kinetic studies showed that the reaction order of toluene on Pd/t-ZrO 2 and Pd/m-ZrO 2 is 0 and 2, respectively. The catalytic activity was controlled by combined effect of PdO activity and quantity, which was correlated with the interaction between palladium and zirconia. The t-ZrO 2 increased PdO species activity, while m-ZrO 2 could enhance the amount of PdO. DFT results showed that the p-band center of the O of PdO on t-ZrO 2 was higher, suggesting that PdO was more active. In situ -DRIFTS revealed that the reaction pathway of catalytic oxidation of toluene on Pd/ZrO 2 was as follows: toluene was oxidized stepwise to benzyl alcohol, benzaldehyde, benzoic acid , CO 2 and H 2 O.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
HIGH PRESSURE RESEARCH
·
2018
·
IF 1.925
Akun Liang,Yinjuan Liu,Hao Liang,Fangming Liu,Cong Fan,Jiawei Zhang,Jinjun Wu,Ji Chen,Duanwei He
The thermal insulation performance of cubic ZrO2–CaO solid solution (CSZ) (16 mol % CaO) and monoclinic ZrO2 (MZ) was investigated in a two-stage multi-anvil press under a pressure of 10 GPa and temperatures up to 1800°C through in situ temperature measurements with the same cell assembly. The results show that the cell temperatures with CSZ as the thermal insulator were always higher than that when thermal insulator was MZ at the same heating power, and the maximum deviation value was 600°C (50% higher) within the measurable range. These two materials were analyzed using X-ray diffraction (XRD), thermal conductivity measurement and scanning electron microscopy. It revealed that the point defects existed in CSZ dominated the thermal insulation performance at high pressure, the same as what at normal pressure. It was also found that the heating process was more controllable when using CSZ as thermal insulator under high pressure.
研究领域:
材料科学
·
热物理
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2022
·
IF 6.044
Le Fu,Bohan Wang,Junjie Song,Chenglong Xu,Guofu Xu,Qiuan Sun,Jiwu Huang,Håkan Engqvist,Wei Xia
The content of crystalline phase plays a significant role in manipulating the microstructure and mechanical properties of glass-ceramics. This study aims at exploring the optimum content of crystalline phase in ZrO 2 –SiO 2 nanocrystalline glass-ceramics (NCGCs) in terms of obtaining the highest mechanical properties. To this end, the mechanical properties of ZrO 2 –SiO 2 NCGCs with 70 mol%, 75 mol%, 80 mol% ZrO 2 were tested and compared with those of the previously prepared NCGCs with ZrO 2 content ranging from 35 mol% to 65 mol%. Results showed that 65 mol% was the optimum content of ZrO 2 in terms of obtaining the highest flexural strength . The flexural strength of NCGCs with ZrO 2 content over 65 mol% was lower than that of the NCGCs with 65 mol% ZrO 2 . This was because the NCGC with 65 mol% ZrO 2 had a homogenous microstructure, with ZrO 2 nanocrystallites homogeneously distributed in an amorphous SiO 2 matrix. Whereas, when ZrO 2 content was increased to 75 mol%, ZrO 2 nanocrystallites were not homogeneously distributed in the SiO 2 matrix anymore. The formation of SiO 2 “holes/canyon” due to ZrO 2 grain coalescence resulted in the decrease of flexural strength. The fracture mechanism and wear properties of the NCGCs were also investigated.
研究领域:
材料科学
·
工程学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Zhaopeng Liu,Youming Ni,Zhongpan Hu,Yi Fu,Xudong Fang,Qike Jiang,Zhiyang Chen,Wenliang Zhu,Zhongmin Liu
The utilization of metal oxide-zeolite catalysts in the syngas-to-olefin reaction is a promising strategy for producing C 2 –C 4 olefins from non-petroleum resources. However, the effect of the crystal phase of metal oxides on the catalytic activity of these oxides is still ambiguous. Herein, typical metal oxides (ZnO/ZrO 2 ) with different crystal phases (monoclinic ( m -ZrO 2 ) and tetragonal ( t -ZrO 2 )) were employed for syngas conversion. The (ZnO/ m -ZrO 2 +SAPO-34) composite catalyst exhibited 80.5% selectivity for C 2 –C 4 olefins at a CO conversion of 27.9%, where the results are superior to those (CO conversion of 16.4% and C 2 –C 4 olefin selectivity of 76.1%) obtained over (ZnO/ t -ZrO 2 +SAPO-34). The distinct differences are ascribed to the larger number of hydroxyl groups, Lewis acid sites, and oxygen defects in ZnO/ m -ZrO 2 compared to ZnO/ t -ZrO 2 . These features result in the formation of more formate and methoxy intermediate species on the ZnO/ m -ZrO 2 oxides during syngas conversion, followed by the formation of more light olefins over SAPO-34. The present findings provide useful information for the design of highly efficient ZrO 2 -based catalysts for syngas conversion.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Xiaodi Li,Shan Ren,Lian Liu,Xiangdong Xing,Lin Chen,Jiangling Li,Jian Yang,Qingcai Liu
The serious deactivation of denitration catalysts caused by heavy metals still a thorny issue in the practical application of selective catalytic reduction of NO x with NH 3 . Herein, we proposed a novel anti-poisoning strategy by designing SO 4 2− /ZrO 2 superacid supported CeO 2 /ZrO 2 catalyst, and the effect of SO 4 2− /ZrO 2 supported CeO 2 /ZrO 2 for PbO-resistance NO x catalytic reduction was investigated. It was worthy to note that the introduction of solid superacid SO 4 2− /ZrO 2 significantly enhanced catalytic performance over the entire temperature range, with an exceptionally high NO x removal efficiency over 98 % during 250–500 °C. When 2 wt% PbO was deposited on the fresh catalyst, the catalytic activity of CeO 2 /ZrO 2 catalyst decreased obviously, while CeO 2 /ZrO 2 -S catalyst can still maintain a higher NO x conversion over 90 % from 275 to 500 °C. The characterization results confirmed that the introduction of solid superacid SO 4 2− /ZrO 2 enhanced the surface acidity and promoted the transformation from Ce 4+ to Ce 3+ . The results of in situ DRIFTS implied that the Eley-Rideal (E-R) mechanism was obeyed over CeO 2 /ZrO 2 catalyst, and both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms were followed over CeO 2 /ZrO 2 -S catalyst in the SCR process. With regard to poisoned catalysts, the NH 3 adsorption was inhibited to some extent, while the reaction mechanism wasn’t changed by PbO poisoning.
研究领域:
催化
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2021
·
IF 5.134
Jun Chen,Hao Yang,Chang-Ming Xu,Ji-Gui Cheng,Ying-Wei Lu
Zirconia microspheres with high sphericity and hardness were successfully massively produced through a cost-effective spray granulation method by using an optimized slurry with high solid content and low viscosity which was formulated with a mixed dispersant . The influence of slurry solid content, binder addition as well as drying temperature on the shape and size of the sintered microspheres were studied. Furthermore, the formation mechanism of different granulated particles was analyzed based on the illustrated migration processes in the ZrO 2 droplets with different contents of water and additives. Under the optimized conditions, the sintered ZrO 2 spheres with tetragonal phase exhibit high sphericity with highest nano-hardness of 9.5 GPa, indicating it is possible to be used in the engineering fields. Such spray granulation method could directly serve for the industrial production of zirconia and other ceramic materials since it is a stable process with high yield, good granulating quality and strong controllability.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Danqing Shen,Qian Du,Pan Wang,Yongquan Zhou,Jianming Pan
The continuous phase films in high internal phase emulsions (HIPEs), which seems to be a microchannel-like space, are benefit for confined synthesis of ultrafine adsorbent. Herein, switchable and microchannel-like space in the continuous phase of oil-in-water HIPEs is developed for fabricating ultrafine ZrO 2 anchoring cross-linked enzyme aggregates (CLEAs-ZrO 2 ), and then as-prepared composites were applied as defluoridation adsorbent. Bis(3-aminopropyl)tetramethyldisiloxane oleic acid surfactant (BTOA) can realize reversible emulsification and demulsification in response to CO 2 /N 2 switch, endowing with simple collection of products and continuous preparation. This confinement effect is expected of resulting in a 28 % increase in adsorption capacity and 33 % reduction in synthesis time. In addition, the adsorption capacity of CLEAs-ZrO 2 is nearly 4.2 times higher than that of commercially available defluoridants. In fluorine-containing industrial wastewater, the removal efficiency of fluoride ion (F - ) reaches 93 %, and the corresponding partition coefficients ( K d ) achieves the value of 31.1 L g −1 . By analyzing with XPS spectra and in-situ FT-IR spectroscopy, a strong Zr-F bonding interaction between CLEAs-ZrO 2 and F - in the solution boosts this specific adsorption. This work presents a novel method for constructing switchable confinement system, but also offers a promising defluoridation adsorbent for industrial effluents.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Xuefeng Liu,Tao Wang,Jianmin Liu,Feng Jiang,Huidong Tang,Guo Feng,Weihui Jiang
High quality single-crystal zirconia nanosheets were successfully prepared via molten salt method, using solvothermally synthesized product as precursor. The effects of heat treatment temperature and soaking time on the phase composition and morphology of samples were investigated by X-ray diffraction, Fourier transform infrared spectroscopy , Thermal analyzer, Raman spectrometer, Field-emission scanning electron microscope and Transmission electron microscope. The results show that zirconia nanosheets with a thickness of 60–80 nm and a width-thickness ratio up to 13 could be obtained by using NaCl and Na 3 PO 4 as composite salts at 900 °C for 5 h. The precursors containing Zr–OH and Zr–O bonds have relatively high activity, which is beneficial to crystal growth. In addition, the as-prepared nanosheets with exposed (001) plane are monoclinic-structured and show no distinct defect. The growth behavior of particles during dissolution-recrystallization process is analogous to self-focusing mechanism. The preparation method can be extended to wet-chemical synthesis of other nanomaterials .
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Xin Xu,Lin-Lin Zhu,Min-Min Dai,Cheng-Cai Zhao,Guang-Xiang Zhang,Yu-Jian Jian,Hua-Tay Lin
Highly transparent polycrystalline Tm 2 O 3 ceramics were successfully fabricated by vacuum sintering at temperatures from 1650 to 1850 °C for 8 h using commercial Tm 2 O 3 and ZrO 2 (1 at%) powders as starting materials. It is the first time that ZrO 2 was reported as a sintering additive to prepare Tm 2 O 3 transparent ceramics. The effects of sintering temperature on the optical transmittance and microstructure of Tm 2 O 3 transparent ceramics were studied. The desired Tm 2 O 3 ceramics with relative density of 99.8% and an average grain size of approximately 9.7 μm were obtained at 1800 °C and the in-line transmittance reached 75% at 880 nm and fluctuated around 80% from 2100 to 2400 nm, respectively. This study demonstrated that Tm 2 O 3 transparent ceramics with higher in-line transmittance and smaller grain size could be prepared by using ZrO 2 as sintering additive at a relatively lower vacuum sintering temperature compared to those already reported in open literatures.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Shujie Liang,Yan Zhang,Jingxian Cong,Jiaxin Lv,Hong Deng
Designing and fabricating nanozymes with photoactivity for CO 2 reduction poses a significant challenge. Here, a hierarchically structured ZFs-tpyNi heterojunction nanozyme, comprising a terpyridine-based Ni complex supported on ZrO 2 nanoframes, has been created through an interfacial engineering strategy for efficient CO 2 reduction under visible light. Due to its unique structural and compositional advantages, ZFs-tpyNi demonstrates superior photocatalytic CO 2 -to-CO conversion compared to its counterpart of ZFs and tpyNi, achieving a CO yield of 18.2 µmol and a selectivity of 92.4 % with a high apparent quantum efficiency of 0.96 % in 3 h. These innovative catalysts also show excellent durability for at least eight cycles without a loss in performance, maintaining a remarkable structural stability with no obvious collapse of its framework and morphology. Systematic investigations reveal that ZFs-tpyNi heterostructures exhibit a high specific surface area advantageous for the effective loading of tpyNi and exposure of active sites. The robust ZFs framework, characterized by extensive porosity, prevents nanoparticle agglomeration and accelerates mass transfer during catalysis. Additionally, the spatially heterogeneous interface enables precise modulation of band alignment and bandgap dynamics in nanozymes, enhancing light absorption and promoting the generation and separation of photogenerated charge carriers. Consequently, the nanozyme demonstrates enhanced CO 2 adsorption and activation capabilities, leading to improved selectivity of catalytic products. This work aims at highlight the role of nanozyme catalysts in sustainable energy production.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Keqiang Zhang,Rujie He,Chen Xie,Gang Wang,Guojiao Ding,Min Wang,Weidong Song,Daining Fang
In this work, high solid loading, low viscosity photosensitive ZrO 2 suspensions with optimized rheological properties for stereolithography based additive manufacturing was developed. The influence of dispersant types, concentrations and solid loading on their dispersion behavior and rheological behavior were studied. In addition, the dispersion mechanism and suspension stability were also characterized. The optimal dispersant and concentration for the suspension with 40 vol% solid loading were KO110 and 2 wt%, respectively. These results revealed that the ZrO 2 suspensions presented near-fluid behavior, which was close to Newtonian flow, resulting in a low viscosity and stability for stereolithography based additive manufacturing. A photosensitive ZrO 2 suspension with a high solid loading of 55 vol% and a low viscosity of 1.65 Pa s at the shear rate of 200 s −1 was achieved when the dispersant and concentration were KOS110 and 2 wt%, respectively.
研究领域:
材料科学
·
增材制造
·
流变学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Le Fu,Wenjun Yu,Bohan Wang,Ying Deng
Extensive efforts have been devoted to investigate the distribution of dopants in ceramics. However, one critical question remained barely explored, which is the redistribution of dopants between amorphous and crystalline phases during fast sintering of ceramics. Here we address this gap by observing the redistribution of five selected dopants (Y, Ce, Yb, Hf, and Ta) in ZrO 2 –SiO 2 nanoceramics during sintering. We designed two groups of experiments: In group one, dual-phase amorphous particles were sintered with multicomponent crystalline ones. The former particles were ZrO 2 –SiO 2 glass, whereas the latter ones consisted of ZrO 2 solid-solution nanocrystallites (SSNCs) embedded in an oxide glass containing Zr, Si, Y, Ce, Hf, Yb, and Ta. In group two, dual-phase crystalline particles were sintered with multicomponent amorphous ones. The former particles were composed of ZrO 2 nanocrystallites (NCs) embedded in an amorphous SiO 2 matrix, whereas the latter ones were oxide glass containing Zr, Si, Y , Ce, Hf, Yb, and Ta. Redistribution of the dopants from the glass to ZrO 2 NCs occurred in the two groups, that is, the five dopants migrated from the glass matrix into the ZrO 2 NCs, forming ZrO 2 SSNCs. The redistribution of the dopants not only increased the configuration entropy of the ZrO 2 NCs but also benefited the network structure integrity of SiO 2 glass. The dopant redistribution process was driven by the minimization of the studied material's free energy. The reported results are important for understanding the redistribution behaviors of dopants and are expected to provide new insights to design new ceramics via the multielement co-doping strategy.
研究领域:
材料科学
·
陶瓷工程
✓ 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）