JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION
·
2017
·Vol. 38
·期 1
·30-36
·
IF 0.938
Sun W. Z.,Cheng J. G.,Huang Z. K.,Jiang Y.,Wu L. E.,Liu L. M.
The present work determined the phase relations in Si-Al-M-O-C (M = Zr, Mg) systems, involving SiC-Al 2 O 3 -ZrO 2 , SiC-Al 2 O 3 -MgO, SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO systems by XRD phase analyses of the solid-state reacted samples from powder mixtures of SiC, Al 2 O 3 , ZrO 2 , MgO and SiO 2 . Within these systems, SiC was respectively compatible with other neighboring phases, forming a set of four-phase compatibility tetrahedrons. The subsolidus phase diagrams of the SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO quaternary systems were presented.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2017
·
IF 3.154
Weiwei Cheng,Guoqin Liu,Xinqi Liu
This research investigated the effects of Fe3+ and antioxidants on the formation of glycidyl esters (GEs) and the free radical mediated mechanisms involving the recognition of cyclic acyloxonium free radical intermediate (CAFRI) for GE formation in both the plant oil model (palm oil, camellia oil, soybean oil, and linseed oil) system and the chemical model (dipalmitin and methyl linoleate) system heated at 200 °C. Results show that Fe3+ can promote the formation of GEs, which can be inhibited by antioxidants in plant oil during high-temperature exposure. Based on the monitoring of cyclic acyloxonium and ester carbonyl group by Fourier transform infrared spectroscopy, the promotion of Fe3+ and the inhibition of antioxidants (tert-butylhydroquinone and α-tocopherol) for GE formation occurred not only through lipid oxidation but also through directly affecting the formation of cyclic acyloxonium intermediate. Additionally, a quadrupole time-of-flight tandem mass spectrometry measurement was conducted to identify the presence of radical adduct captured by 5,5-dimethylpyrroline N-oxide, which provided strong evidence for the formation of CAFRI. Thus, one possible influencing mechanism can be that free radical generated in lipid oxidation may be transferred to dipalmitin and promote CAFRI formation. Fe3+ can catalyze free radical generation while antioxidants can scavenge free radical, and therefore they also can directly affect CAFRI formation.
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 4
·775
·
IF 5.3
Hong Su,Jiangping Liu,Yanan Hu,Tianhao Ai,Chenhao Gong,Jichang Lu,Yongming Luo
As a representative sulfur-containing volatile organic compounds (S-VOCs), CH3SH has attracted widespread attention due to its adverse environmental and health risks. The performance of Mn-based catalysts and the effect of their crystal structure on the CH3SH catalytic reaction have yet to be systematically investigated. In this paper, two different crystalline phases of tunneled MnO2(α-MnO2and β-MnO2) with the similar nanorod morphology were used to remove CH3SH, and their physicochemical properties were comprehensively studied using high-resolution transmission electron microscope (HRTEM) and electron paramagnetic resonance (EPR), H2-TPR, O2-TPD, Raman, and X-ray photoelectron spectroscopy (XPS) analysis. For the first time, we report that the specific reaction rate for α-MnO2(0.029 mol g−1h−1) was approximately 4.1 times higher than that of β-MnO2(0.007 mol g−1h−1). The as-synthesized α-MnO2exhibited higher CH3SH catalytic activity towards CH3SH than that of β-MnO2, which can be ascribed to the additional oxygen vacancies, stronger surface oxygen migration ability, and better redox properties from α-MnO2. The oxygen vacancies on the catalyst surface provided the main active sites for the chemisorption of CH3SH, and the subsequent electron transfer led to the decomposition of CH3SH. The lattice oxygen on catalysts could be released during the reaction and thus participated in the further oxidation of sulfur-containing species. CH3SSCH3, S0, SO32−, and SO42−were identified as the main products of CH3SH conversion. This work offers a new understanding of the interface interaction mechanism between Mn-based catalysts and S-VOCs.Keywords:CH3SH decomposition;MnO2;oxygen vacancies;oxygen migration
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Mengyue Ma,Zhihua Zhang,Yu Huan,Wang Liu,Mingwen Zhao,Tao Wei
Oxide-ionic conductors are broadly used as catalytic, conducting and detecting materials under oxidizing, reducing, inert or mixed environments. However, their current issue is the demand of high work temperatures (> 600 °C) to maintain high oxide-ion conductivity (> 0.1 S cm −1 ). This work develops a Pb 5 CaBi 10 O 21 (PCBO) ceramic, and its low melting point corresponds to the low binding energy of metal-O, which facilitates the generation of lattice oxygen vacancies and the migration of oxygen ions. PCBO lowers the working temperature to 300–500 °C, and demonstrates the highest oxygen-ion transport of ever reported oxide-ionic conductors, showing 0.68 oxide-ionic transport number, 0.353 ml min −1 cm −2 oxygen flux and 0.16 S cm −1 oxide-ionic conductivity (3–5 orders of magnitudes higher than YSZ or SDC at 500 °C). The high oxide-ionic percentage and conductivity were further demonstrated by the voltage/power output of SOFCs with PCBO as electrolyte. The experimental investigation and density functional theory calculation both demonstrate the easy formation and migration of V O in PCBO, explaining its high oxygen-ion transport.
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2019
·
IF 6.355
Daxin Li,Zhihua Yang,Dechang Jia,Xiaoming Duan,Delong Cai,Shengjin Wang,Jingkun Yuan,Yu Zhou,Dongli Yu,Yongjun Tian
High-temperature oxidation behavior of dense amorphous boron-rich Si 2 B 1-4 C 2 N monoliths in flowing air was studied in detail. The oxidation products are those of amorphous silica and cristobalite that control the diffusion of oxygen inward. Oxygen diffusion leads to a dense and passivating scale, which acts as a barrier to oxygen. Amorphous boron-rich monoliths oxidize through a classical parabolic manner. The amorphous nature, three-layers structure of oxide scale and varying chemical bonds are primarily responsible for the oxidation resistance with respect to the nano monoliths. The increase in boron content is revealed to weaken the oxidation resistance of the amorphous Si 2 B 1-4 C 2 N monoliths.
研究领域:
材料科学
·
无机非金属材料
·
高温功能材料
·
陶瓷基复合材料
·
表面与界面化学
✓ 已验证
DOI
高影响因子
ACS ES&T Water
·
2024
·
IF 4.8
Sicheng Liu,Pan Li,Wanmeng Lu,Yahong Yang,Enchao Li,Shengji Xia,Daqiang Yin
The treatment capacity of ozone advanced oxidation technology for industrial wastewater is limited due to ozone’s inherent selective degradation of complex matrix components, leading the process from rapid oxidation to slow oxidation. Based on the influences of gas–liquid mass transfer characteristics and chemical reactivity on the rapid and slow oxidation processes of ozone, a synergistic process of ozone micro/nanobubbles (MNBs/O3) and H2O2 based on oxidation–reduction potential (ORP) is proposed to achieve deep removal of the ozone-resistant matrix in industrial wastewater. In deionized water, a second-order reaction kinetic method based on ozone and •OH exposure is used to assess the sensitivity of the ORP to identify the oxidation stage of MNBs/O3. Under different pH conditions, the feasibility of ORP real-time monitoring for reflecting the degradation efficiency of organic pollutants in actual dyeing wastewater effluent is further determined through batch experiments. The upward inflection point of the ORP effectively marks the end of the predominantly mass transfer-driven rapid ozonation process, which is likely the critical saturation phase point of ozone. The results further indicate that staged addition of H2O2 based on the upward inflection point of ORP in the MNB ozonation reaction is a more promising approach for deep removal of resistant pollutants.
研究领域:
环境工程
·
化学工程
·
水处理技术
·
高级氧化工艺
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Minglei Yan,Junjie Zhang,Cong Wang,Lang Gao,Wengang Liu,Jiahao Zhang,Chunquan Liu,Zhiwei Lu,Lijun Yang,Chenglu Jiang,Yang Zhao
Designing inexpensive, high-efficiency and durable bifunctional catalysts for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) is an encouraging tactic to produce hydrogen with reduced energy expenditure. Herein, oxygen vacancy-rich cobalt hydroxide/aluminum oxyhydroxide heterostructure on nickel foam (denoted as Co(OH) 2 /AlOOH/NF-100) has been fabricated using one step hydrothermal process. Theoretical calculation and experimental results indicate the electrons transfer from Co(OH) 2 to highly active AlOOH results in the interfacial charge redistribution and optimization of electronic structure. Abundant oxygen vacancies in the heterostructure could improve the conductivity and simultaneously serve as the active sites for catalytic reaction. Consequently, the optimal Co(OH) 2 /AlOOH/NF-100 demonstrates excellent electrocatalytic performance for HER (62.9 mV@10 mA cm -2 ) and UOR (1.36 V@10 mA cm -2 ) due to the synergy between heterointerface and oxygen vacancies. Additionally, the in situ electrochemical impedance spectrum (EIS) for UOR suggests that the heterostructured catalyst exhibits rapid reaction kinetics, mass transfer and current response. Importantly, the urea-assisted electrolysis composed of the Co(OH) 2 /AlOOH/NF-100 manifests a low cell voltage (1.48 V @ 10 mA cm -2 ) in 1 M KOH containing 0.5 M urea. This work presents a promising avenue to the development of HER/UOR bifunctional electrocatalysts.
研究领域:
材料科学
·
电催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2022
·Vol. 11
·期 7
·903
·
IF 5.561
Mei-Hui Pian,Lu Dong,Zhen-Ting Yu,Fan Wei,Chun-Yang Li,Dan-Cai Fan,Shi-Jie Li,Yan Zhang,Shuo Wang
This study aimed to compare ozone-microbubble-washing (OM) performed by domestic equipment with conventional water-washing (CW) regarding resultant quality attributes of muscle foods. For this purpose, muscle microstructure and lipid and protein oxidation were evaluated in pork and fish samples after OM and CW treatments. The assessment of muscle microstructure showed that OM treatment did not damage the microstructure of muscle fibers in both pork and fish samples. Thiobarbituric acid reactive substances (TBARS) values were not detected in both treatment groups, and they were substantially below the generally acceptable threshold (1 mg MDA/kg). The methylglyoxal (MGO) level of OM-treated fish samples was significantly higher than that of CW-treated fish samples. However, glyoxal (GO) and MGO levels of OM-treated pork samples were significantly lower than that of CW-treated pork samples. Similar types and sites of oxidative modification and similar numbers of modified peptides, as well as no significant difference in the concentration of total and most of the free amino acids (FAA) between treatment groups, indicated that OM treatment did not accelerate protein oxidation.Keywords:ozone-microbubbles-washing;ozone;domestic ozone equipment;washing treatment;pork;fish;oxidation
研究领域:
食品科学
·
肌肉生物学
·
氧化应激
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Gui Liu,Lei Sun,Junhua Liu,Fang Wang,Curtis J. Guild
Mn-Ce mixed oxides, synthesized by co-impregnation method, have been used in the catalytic oxidation of primary amines to corresponding nitriles. The effects of Mn/Ce molar ratio on the structure and catalytic properties were investigated, and the results showed the Mn x Ce 1-x O s mixed oxides exhibited higher catalytic activity than MnO x or CeO 2 . It was found that favorable selectivity and the best conversions for benzylic, heterocyclic, and aliphatic primary amines were obtained when the Mn/Ce atomic mole ratio was 2:1 (denoted as Mn 0.67 Ce 0.33 O s ). These materials have been investigated using XRD, FT-IR, SEM, HRTEM, XPS, DR-UV–vis, H 2 -TPR, and EPR techniques. XRD results showed that the samples did not appear any diffraction of manganese oxides. SEM images showed that the nanoparticles of the mixed oxides can be uniformly distributed than MnO x or CeO 2 . HRTEM micrographs exhibited that Mn-Ce mixed oxides were all exposed (111) and (220) planes corresponding to CeO 2 , and Mn 0.67 Ce 0.33 O s catalyst had the highest mutual solubility, thus this catalyst could have the stronger interaction than other Mn-Ce mixed oxides, which was in accordance with XPS, H 2 -TPR, and EPR analysis. XPS studies confirmed that the highest concentration of Ce 3+ was obtained at the surface of Mn 0.67 Ce 0.33 O s sample, this situation provides a basis for the formation and stabilization of oxygen vacancies, and it is beneficial for oxidation reaction, which is in consistent with DR-UV–vis results. In addition, XPS data also showed that Mn 0.67 Ce 0.33 O s sample provided the most adsorbed oxygen species, this suggested that the mobility and availability of the active oxygen species were enhanced. This conclusion also can be drawn from H 2 -TPR analysis. EPR studies further supported the formation of Mn 0.67 Ce 0.33 O s solid solution. Based on the above analysis, the excellent catalytic performance should be attributed to the formation of a solid solution with the incorporation of Mn x+ into the CeO 2 cubic fluorite lattice, this reduces the formation energy of oxygen vacancies and enhances the mobility of active oxygen species from the bulk to the catalyst surface.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
FUEL
·
2018
·
IF 4.908
Bo Wang,Xiong-Min Liu,Xia-Na Fu,Yuan-Lin Li,Pin-Xian Huang,Qiang Zhang,Wei-Guang Li,Li Ma,Fang Lai,Peng-Fei Wang
In this work, thermal oxidation reaction of dimethoxymethane (DMM) at low temperature was investigated with a custom-designed mini closed pressure vessel test (MCPVT) employed. The initial auto-oxidation, thermal decomposition and deep radical oxidation processes were revealed by analyzing the behavior of oxidation temperature (T) and pressure (P) in the process of MCPVT monitoring. Peroxides generated from DMM auto-oxidation were measured by iodimetry and thin-layer chromatography (TLC). The dominant peroxide was separated from oxidation products via column chromatography, with structure characterized by mass spectrometry (MS), 1 H and 13 C nuclear magnetic resonance (NMR). The thermal decomposition characteristics were determined by differential scanning calorimeter (DSC). Results show that the oxidation was mainly initiated by hydrogen abstraction on the methylenedioxy (O-CH 2 -O) of DMM when temperature was above about 310 K. The primary product of hydroperoxide, hydroperoxy(methoxymethoxy)methane was found in DMM oxidation for the first time, with a high level. Its exothermic onset temperature (T 0 ) and decomposition heat (Q DSC ) are 372.87 K and 2431.37 J·g −1 , respectively. The thermal decomposition could lead to thermal runaway of oxidation, and further transform into an explosion. In most cases, the release of radical pool after peroxides decomposition would induce a rapidly radical oxidation of DMM through an endothermic reaction at about 410 K.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 12
·3323-3333
·
IF 3.146
Liu Dong-yan,Lou Wen-bo,Sun Shi-neng,Zhang Yang,Zhang Ying,Zheng Shi-li
The recovery of iron phosphate involves the addition of oxidizer to oxidize Fe 2+ in the spent LiFePO 4 (LFP) material to Fe 3+ and the agent commonly used is hydrogen peroxide (H 2 O 2 ). Nevertheless, H 2 O 2 has disadvantages of high price, easy decomposition and low utilization efficiency. In this manuscript, a facile method is proposed for efficient synergistic oxidation of Fe 2+ in spent LFP leachate with a mixture of oxygen and ozone. Specifically, we found by thermodynamic computations that the dominant oxidation groups of ozone during oxidation varied with acidity. The oxidation would produce a large number of iron-phosphate complex groups (Fe 3 H 6 (PO 4 )
3+ 4
, FeH 8 (PO 4 )
− 4
and Fe 2 HPO
4+ 4
) in the phosphorus-sulfur mixed acid system, leading to a paradoxical pH drop. The optimized conditions for H 2 O 2 oxidation were explored. It was determined experimentally that oxidation by gas mixture and O 2 belonged to the firstorder and second-order reactions with activation energies of 28.68 kJ/mol and 34.61 kJ/mol, respectively, which were both controlled by a mixture of chemical reaction and diffusion. The optimized oxidation method was finally determined by evaluating the cost and oxidation rate of the oxidizers. The results in this study offer a promising method for new low-cost and efficient Fe 2+ oxidation for industrial production.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Liyong Ding,Yukun Zhao,Youji Li,Chengsheng Ge,Liang Lv,Hongwei Ji,Wenjing Song,Chuncheng Chen,Jincai Zhao
During TiO 2 -based photocatalysis, the presence of water usually leads to the unselective degradation of organic compounds due to the uncontrollable formation of water-derived radical species. Here we report that the presence of water dramatically enhances the selectivity in photocatalytic oxidation of sulfides to sulfoxides over TiO 2 . H 2 18 O-isotope labelling experiments reveal that both O 2 and H 2 18 O contribute to the oxygen atoms in the formed sulfoxides and sulfones. Moreover, at the beginning of the oxidation of sulfides, water serves as the main source of the oxygen atom, while the contribution of O 2 increases with the irradiation time. We uncover two roles of water in sulfides oxidation: to act as oxygen source in the oxidation of sulfides to sulfoxides; to provide protons to inhibit the further oxidation of sulfoxides. This study deepens our understanding of roles of water in photocatalytic oxidation of sulfides and offers a new strategy to optimize photocatalytic selective oxidation .
研究领域:
化学
·
环境科学
·
材料科学
✓ 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）