MATERIALS SCIENCE FORUM
·
2015
·
IF 0
Gang Chen,Chun Wei Gong,Chun Lin Fu,Xiao Dong Peng,Wei Cai,Rong Li Gao,Xiao Ling Deng
(Sr1-xBax) 2(Nb0.9Ta0.1) 2O7 (SBNT) ceramics were prepared by solid state reaction. The crystal structure of SBNT ceramics, surface morphology and dielectric properties were studied using XRD, SEM and LCR instrument analyzer, respectively. The results show that the grain size decreases with increasing Ba concentration, and all samples show single phase, no second phase can been observed. Addition of Ba ion can improve the dielectric properties of SBN ceramics. The dielectric constant increases first, then decreases; the maximum value (εr=97) can be obtained at x=0.1, the dielectric constant changes slightly with increasing wide frequency.
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DOI
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Chen Cai,Jiayin Chen,Wei Fu,Shuying Ning,Hao Zhou,Muhammad Kashif,Yaxin Su
The Ce-modified OMS-2 catalyst (Ce x -OMS-2) was synthesized by the hydrothermal synthesis method, after which its catalytic efficacy in the selective reduction of NO by CO was assessed. The experiments showed that Ce 0.08 -OMS-2 was capable of 100% NO conversion between 175 and 300 °C when 0.05%NO, 0.1%CO, 5%O 2 and N 2 were used as equilibrium gases, and the N 2 selectivity peaked at 93.2% at 175 °C. Additionally, Ce 0.08 -OMS-2 exhibits good sulfur resistance in the presence of 0.02% SO 2 and maintains more than 88% NO conversion at 175–275 °C. By using BET, XPS, H 2 -TPR, NH 3 -TPD, and In situ DRIFTS to characterize the catalysts, the effects of doping the active metal Ce on the physicochemical characteristics of OMS-2 catalysts were under investigation. In conclusion, the improvement of the low-temperature activity of the Ce x -OMS-2 catalyst is facilitated by lower agglomeration and crystallinity , larger specific surface area, smaller average pore size, enhanced surface oxygen vacancies, increased Mn 4+ concentration, and richer Brønsted acid. Reaction gas adsorbed species and intermediates on the catalyst surface were dynamically captured during In situ DRIFTS experiments. The CO-SCR reaction of the catalyst was found to follow the E-R mechanism below 200 ℃ and the L-H mechanism at 200–350 ℃.
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DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 96
·期 9
·1925-1934
·
IF 0.791
Zhang Haifu,Lu Xinhuan,Li Xixi,Wang Beibei,Dong Yanhong,Zhou Dan,Xia Qinghua
Abstract The epoxy compounds are useful intermediates and precursors in the production of fine chemicals and drugs. In the epoxidation reaction system, Co-MOF, a kind of cobalt-based heterogeneous catalytic material, has been widely studied for its simple synthesis, stable structure and excellent ability of molecular oxygen activation. For the first time, we used potassium persulfate as the initiator for the efficient air epoxidation reaction catalyzed by Co-MOF materials, which had better catalytic effects than aldehydes or peroxy compounds. As a new initiator, potassium persulfate reduces the reaction temperature and increased the amount of substrate olefins. In addition, potassium persulfate reduced the activation energy of the reaction, so that the ratio of olefin to initiator was further reduced, showing a better efficiency than initiators of aldehydes or peroxy compounds. Moreover, the application of potassium persulfate to the epoxidation reaction of other catalysts has also achieved good results.
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Wanjun Guo,Zhi-Qiang Wang,Shuang Xiang,Yaxuan Jing,Xiaohui Liu,Yong Guo,Xue-Qing Gong,Yanqin Wang
ABSTRACT Owing to the wide application of primary amines, their selective production via reductive amination has become a crucial research topic. Various metal-supported catalysts (Pt, Ru, Rh, Ir, Co, Ni, etc. ) have been investigated, and metallic species have been recognized as active sites in recent years. Herein, we reveal for the first time that CoO species containing oxygen vacancies within a core-shell-structured Co@CoO catalyst accelerate the ammonolysis of Schiff bases, key intermediates in reductive amination, through NH 3 dissociation to hydride-like NH 2 δ – species, delivering an excellent reductive amination performance. The catalyst is highly stable and was utilized in 10 catalytic cycles for the amination of biomass-derived cyclopentanone (CPO) to cyclopentylamine (CPA) without deactivation. Various computational models in combination with spectroscopic measurements indicated that this catalyst not only drives the dissociation of H 2 to the active H δ – species, but also enables the homolytic cleavage of NH 3 to NH 2 δ – . D 2 isotopic tracing experiments provided further evidence of the direct involvement of hydride-like NH 2 δ – species in Schiff base ammonolysis. Theoretical calculations verified the stable co-adsorption of H δ – and NH 2 δ – , which allows the Schiff base to move freely on the surface of the CoO shell and participate extensively in molecular collisions, resulting in exceptional catalytic activity. This is the first study that demonstrates the potential of metal oxide catalysts for the production of primary amines via reductive amination.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Hongming Liu,Jingxin Wang,Hai Xiong,Yue Chen,Jianzhong Xiao,Chao Wang
Restricted by an insufficient understanding of the compositional and structural characteristics of the sensing materials that affect the sensing performances, the YSZ-based CO gas sensor remains in a dilemma in terms of further promoting sensitivity, selectivity and long-term stability. In this work, two bimetallic oxides with different crystal structures, perovskite SmMnO 3 and mullite SmMn 2 O 5 , were prepared and adopted to elucidate the roles of the Mn 3+ , Mn 4+ and surface oxygen vacancies . Compared with SmMnO 3 , the coexisting coordination modes of Mn 3+ and Mn 4+ in SmMn 2 O 5 is conducive to generating oxygen vacancies. Furthermore, a SmMn 2 O 5 -based sensor with more oxygen vacancies demonstrates a relatively faster response/recovery speed and enhanced sensitivity of 2.05 times that of SmMnO 3 under the same operation conditions. Such work may broaden insight into the development of efficient sensing materials that introduce oxygen vacancies through the construction of phase structures without complicated operations. Overall, the sensor attached to SmMn 2 O 5 exhibits a low detection limit (5 ppm), a feasible response/recovery speed (24 s/28 s toward 40 ppm CO operating at 450 °C), satisfactory CO selectivity and long-term stability, highlighting its potential for CO monitoring in harsh environments.
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DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2014
·
IF 4.558
Linglei Jiang,Ying Huang,Qi Zhang,Hongyan He,Yun Xu,Xuefeng Mei
Pharmaceutical co-crystals involving two active pharmaceutical ingredients are rarely revealed in the literature. In this work, crystal engineering principles were exercised to guide the design and synthesis of the Biopharmaceutics Classification System class IV drug dapsone (DAP). We reported six drug–drug co-crystals of DAP with sulfanilamide, flavone, luteolin, caffeine in 1:1 stoichiometry, caffeine in 1:2 stoichiometry, and 2(3H)-benzothiazolone. Bioactive coformers were deliberately selected. The resulting co-crystals were fully characterized by a range of analytical technologies, including X-ray powder diffraction, Fourier transform infrared spectroscopy, polarized light microscopy, differential scanning calorimetry, and thermogravimetric analysis, etc. Single-crystal structure analysis reveals that reoccurring supramolecular synthons are observed in different DAP co-crystals. Equilibrium solubility and intrinsic dissolution rates were also compared with those of the parent drug. This work expands the pharmaceutically acceptable solid forms of DAP and supplements the successful cases of drug–drug co-crystals.
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DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2010
·Vol. 31
·期 21
·1886-1891
·
IF 4.263
Wei Xiong,Hanfu Wang,Yanchun Han
Novel dendritic triblock co-oligomer (14G2A3) consisting of ester dendrons and aniline oligomer was synthesized and found to self-assemble into fibrils in THF. Studies reveal that the formation of the fibrils originates from both of the amphiphilic interactions between the ester dendrons and oligoaniline, as well as the intermolecular π-π stacking among oligoanilines. The shape effect of dendrons on molecular packing was comparatively analyzed with packing parameter against its linear analogous compound. At the same time, the driving forces that dominate the final aggregating state of the block oligomer were separately investigated using the bulky-group protecting method, which allows release of the intermolecular π-π stacking of oligoaniline in a controlled manner. Results show that both the introduction of dendrons and the intermolecular π-π stacking will increase the packing parameter of the block oligomer and, consequently, cause the self-assembly morphology to evolve step by step from micelles to vesicles and finally to fibrils. The fibrils can form complexes with SWNTs to increase solubility in THF. The effective fluorescence quenching accompanied also opens a gate for the block co-oligomer to have potential applications in organic electronic devices.
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DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
·
2015
·Vol. 38
·期 5
·1149-1154
·
IF 1.017
DENG TIAN,ZHANG CHONGRONG,XIAO YUYUAN,XIE ANRAN,PANG YUE,YANG YANZHAO
The samarium-doped ceria (SDC) nanospheres were prepared by the one-step hydrothermal method and characterized by transmission electron microscope, scanning electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectrometer and Raman spectra. According to the results, samarium was doped into the lattice successfully. The as-prepared samples were dispersed well and the average diameter was 60 nm. It showed better catalytic performance than pure ceria and the most appropriate concentration of doping was found.
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DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2025
·
IF 7.8
Qingling Meng,Kaicheng Sun,Chongrui Zhang,Zhao Wen,Mengmeng Wang,Zijian Wang
s The environmental transport of antibiotics is influenced by their chemical properties and environmental conditions, with graphene oxide (GO) acting as a pollutant carrier that alters their behavior. This study investigated the transport mechanisms of sulfamethoxazole (SMX) and tetracycline (TC) across pH 5.0–9.0, humic acid (HA) concentrations of 0–10 mg L −1 , and a range of GO concentrations, using quartz sand columns, batch experiments, and modeling. TC exhibited strong adsorption in fine sand (max 44.5 mg kg −1 ) via carboxyl complexation and electrostatic attraction, while SMX showed high mobility due to hydrophilicity and weak polarity. Elevated pH enhanced TC migration by weakening adsorption through electrostatic repulsion but had little effect on SMX. HA promoted TC migration via complexation but had minimal impact on SMX. GO significantly enhanced TC migration (up to 42.9 % at 30 mg L −1 GO) by providing adsorption sites, while both antibiotics facilitated GO dispersion by altering its surface charge. Alkaline conditions accelerated TC-GO migration via electrostatic repulsion, whereas acidic conditions strengthened SMX-GO interactions. Fine sand inhibited TC-GO transport via pore clogging, while HA further promoted co-transport. These findings elucidate how antibiotic properties and GO-related environmental factors jointly regulate pollutant transport, aiding groundwater-soil contamination control.
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Shengbin Dong,Man Wang,Hu Li,Hui Fu,Jie Yang,Minghui Zhu
Low-temperature catalytic oxidation has emerged as one of the most effective methods for removing carbon monoxide due to its economic feasibility. Copper-based (Cu-based) catalysts are increasingly regarded as viable alternatives to noble metal catalysts. While the incorporation of indium (In) into Cu-based catalysts has gained popularity, the impact of the In oxide (In2O3) phase on catalyst performance remains unclear. In this study, we prepared two different In2O3 with cubic (cb) and rhombohedral (rh) phases. Cu is supported on In2O3 via the impregnation method. The Cu/In2O3 catalyst with a cubic phase exhibited a higher CO oxidation activity (T90 = 122 °C). The primary reason for this enhanced activity is that the cubic phase of the In2O3 support promoted the generation of the surface Cu+ species. Based on the in situ DRIFTS results, Cu+ species and Cu+-CO species serve as active sites and active intermediates, respectively, in the CO oxidation reaction.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Ziyi Deng,Xiaohan Li,Gaosheng Zhang,Guicong Xiao,Yuan Xie,Ru Nie,Shenglin Mai,Jianyou Long,Ziqing Xiao,Ping Zhang,Huosheng Li
Hypochlorite (ClO − )-based chlorination has shown effectiveness in oxidizing and purifying ammonium nitrogen (NH 4 + -N) and thallium (Tl) individually. However, the co-removal of these contaminants remains understudied. Addressing this gap, our study investigated the behaviors and mechanisms of NaClO-based breakpoint chlorination in oxidizing and removing both Tl and NH 4 + -N. The interaction among thallous ions (Tl + ), NH 4 + -N and NaClO in wastewater created a synergistic oxidation effect, which led to high removal efficiencies, exceeding 97 % for both Tl and NH 4 + -N, achieved with a NaClO concentration of 7 mmol/L, across a pH range of 6 to 10 in less than 5 min. Notably, the presence of Tl + , rather than Tl 3+ or Tl 2 O 3 , significantly enhanced the conversion of hypochlorite alongside NH 4 + -N. This coupled process generated chloramines and nitroxyl, along with oxygen-independent hydroxyl radicals formation, which further transformed into chloride radicals, dichlorine radical anions, and chlorine oxide radicals. Introducing these highly reactive species into the binary-pollutant system marked a substantial improvement over single-pollutant systems, yielding significantly higher removal efficiencies. These findings shed new light on the role of Tl in breakpoint chlorination for wastewater containing both Tl and NH 4 + -N.
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产品关联
DOI
高影响因子
Small
·
2015
·Vol. 11
·期 24
·2893-2902
·
IF 8.368
Yuefei Wang,Renliang Huang,Wei Qi,Yanyan Xie,Mengfan Wang,Rongxin Su,Zhimin He
The wetting and drying of drops on flexible fibers occurs ubiquitously in nature, and the capillary force underlying this phenomenon has motivated our great interest in learning how to direct supramolecular self-assembly. Here, the hierarchical co-assembly of two aromatic peptides, diphenylalanine (FF) and ferrocene-diphenylalanine (Fc-FF), is reported via sequential, combinatorial assembly. The resulting dandelion-like microstructures have highly complex architectures, where FF microtube arrays serve as the scapes and the Fc-FF nanofibers serve as the flower heads. Homogeneous FF microtubes with diameters tailored between 1 and 9 μm and wall thickness ranging from 70 to 950 nm are initially formed by controlling the degree of supersaturation of the FF and the water content. Once the FF microtubes are formed, the growth of the dandelion-like microstructures is then driven by the capillary force, derived from the wetting and drying of the Fc-FF solution on the FF microtubes. This simple and ingenious strategy offers many opportunities to develop new and creative methods for controlling the hierarchical self-assembly of peptides and thus building highly complex nano and microstructures.
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产品关联
DOI
PubMed
高影响因子
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