NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 32
·14406-14413
·
IF 3.591
Yubo Liu,Guoqiang Ding,Guoping Zhao,Haohao She,Yulei Zhu,Yong Yang
Combining glucose dehydration and the subsequent hydrogenation in one pot is a preferable approach for process development as such a method allows in situ generation of the reactive intermediate to undergo further reaction without extra energy-intensive separation. Herein, phosphotungstic acid and various types of titania (anatase, rutile, P25) supported Ru-based catalysts were considered as the dehydration and hydrogenation catalysts, respectively. Modulating the different reactant media (N2, H2), various products were obtained with GBL–H2O as the solvent. A considerable yield (42%) of levulinic acid (LA) and γ-valerolactone (GVL) (40%) were obtained in nitrogen and subsequent hydrogen. Ru/TiO2 (rutile) was the favorable hydrogenation catalyst among the three types of Ru/TiO2. Meanwhile, a certain amount of sorbitol (36%) was obtained in pure hydrogen. The hydrogenation of glucose is more likely to occur than the glucose dehydration. The physicochemical properties of the catalysts were characterized by XRD, BET, TPR, STEM and in situ CO/FT-IR, and the results show that well-dispersed Ru particles are located on the rutile crystallites, which facilitated the hydrogenation of LA. A strong metal support interaction (SMSI) was responsible for the various microstructure properties and the different hydrogenation reactivity. This work allows a better understanding of the reaction paths of glucose conversion.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Hao Zhu,Shunyan Ning,Zengzhiqiang Li,Xinpeng Wang,Toyohisa Fujita,Yuezhou Wei,Xiangbiao Yin
Here, a nano disc-shaped bimetallic organic framework (NbCo-piperazine) was prepared by the solvothermal method for the activation of PMS for the degradation of contaminants. The effects of Nb/Co ratio, synthesis time and temperature on the morphology, structure and performance of the NbCo-piperazine catalyst were characterized by XRD, FT-IR, SEM-EDS and TEM. The optimum conditions for NbCo-PZ to activate PMS degradation of tetracycline were investigated by adjusting the dosage of catalyst, tetracycline concentration, pH and PMS concentration. The catalytic performance of NbCo-PZ in the presence of co-existing anions (Cl − , NO 3 – , HCO 3 2– , H 2 PO 4 − ) was also evaluated. XPS explained that cyclic changes in the valence states of Nb 4+ /Nb 5+ and Co 2+ /Co 3+ accelerated the activation of the PMS degradation process. EPR results showed the presence of free radicals (SO 4 ·− , ·OH and O 2 ·− ) and non-free radicals ( 1 O 2 ) in the degradation process, with free radicals playing a major role in the degradation process. The degradation rate of tetracycline after three cycles was 92.2%. In addition, NbCo-piperazine showed good catalytic performance for other organic pollutants such as methyl blue, tylosin tartrate and tetracycline with the degradation rate of 97.8%, 95.2% and 95.5%, respectively. Moreover, it also has good catalytic properties in various water systems such as river water and sea water.
研究领域:
环境化学
·
催化
·
水处理
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Shiwei Feng,Chengping Zhang,Hengdao Quan
As an environmentally friendly cleaning agent, Z -1-chloro-3,3,3-trifluoropropene (HCFO-1233zd( Z )) can realize industrial production by the isomerization of HCFO-1233zd( E ). Herein, various isomerization catalysts with different structures, compositions and acid properties were prepared through the fluorination of γ-Al 2 O 3 with CHF 3 by controlling the activation conditions. For the first time, the catalysts for HCFO-1233zd( E ) isomerization were systematically studied by XRD, N 2 physisorption, XPS, SEM, MAS NMR spectroscopy, NH 3 -TPD and py-IR. The active site of this reaction was revealed and the catalyst deactivation mechanism was proposed. It turned out that HCFO-1233zd( E ) isomerization prefers to occur at Lewis acid sites with moderate density and strength. The amorphous particles composed of γ-Al 2 O 3 , Al 2 O 3 (F) and α-AlF 3 ( R 3 ¯ c ) at 450 °C exhibit highly catalytic activity for HCFO-1233zd( E ) isomerization. After 100 h evaluation, it was found that residual γ-Al 2 O 3 can be fluorinated by HCFO-1233zd( E ) to form needle-like structures which could induce the amorphous Al 2 O 3 (F) particles to reorganize and give cubic structures, where the Lewis acid properties were enhanced, leading to catalyst deactivation.
研究领域:
催化
·
化学工程
·
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
ACTA MATERIALIA
·
2023
·
IF 9.4
Junyan Gao,Peng Liu,Jinshu Wang,Ruimin Zhang,Yunfei Yang,Wenyuan Zhou,Hexiong Liu,Junhao Sun
The size and distribution of Sc 2 O 3 in the composite powder precursor has great effect on the emission property of scandate cathode. By one-step in-situ synthesis method, the composite powder exhibits the structure of quasi-spherical Sc 2 O 3 nanoparticles grown in situ on the surface of W/Ir grains, and the obtained W–Ir cathode with 3wt % Sc 2 O 3 could provide the emission current density of 83.43 A/cm 2 at 900 °C b , which is higher than other W–Ir mixed matrix scandate cathodes and W matrix scandate cathode. The XRD results showed that the high emission ability depended on the high content of active phase α-Ba 2 ScAlO 5 and low content of non-active phase BaAl 2 O 4 . In-situ TEM has been applied to observe the microstructure evolution of the cathode surface at high temperature for the first time. A serial change in the microstructural features of cathode surface and the migration of Ba, Sc and O on the substrate surface has been found, confirming the formation of Ba-Sc-O active layer. The first-principles calculations indicate that the active substances (Sc) are more stable (low adsorption energy of − 8.58 eV) on the IrW matrix cathode surface than on the tungsten matrix cathode surface, which is consistent with the low evaporation rate of the active substance detected by TFMS technique. Besides, the interaction between the active substance and the matrix was strengthened due to more electron transfer of Sc (1.88 e) and Ba (1.45 e), therefore lowering the work function . The feasible preparation technique makes such a cathode promising for applications in high-power microwave devices.
研究领域:
材料科学
·
电子工程
·
表面科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 4
·1537-1549
·
IF 3.5
Chen Yongjin,Li Yaru,Fu Jianbo,Zhang Mi,Ren Hui,Jiao Qingjie
Aluminum hydride (AlH 3 ), as a potential new metal fuel, has attracted extensive attention in the field of hydrogen storage materials, propellants and energetic materials due to its excellent properties. In this paper, a new organic liquid phase reduction method was used to prepare AlH 3 , and the microstructure and composition of the prepared samples were characterized by SEM–EDS, XRD, FT-IR, XPS, etc. The main crystal phase of the prepared AlH 3 was α-AlH 3 , with high quality and no other impurities. The thermal decomposition behavior and non-isothermal reaction kinetics of AlH 3 were investigated by TG-DSC. The results show that there are three exothermic stages in the heating process of AlH 3 : dehydrogenation of AlH 3 , first oxidation of Al, and second oxidation of Al. The activation energy of the dehydrogenation of AlH 3 is 77.8675 kJ/mol (Kissinger method) and 81.4862 kJ/mol (Ozawa method), respectively. The morphology evolution of AlH 3 particles during the heating process (300–3000 K) was simulated using a reaction kinetics method based on the ReaxFF force field. The response behavior of AlH 3 in the instantaneous high-temperature detonation environment was investigated using the high-energy laser-induced shock wave technique. Under the impact of a high-energy laser (1006 mJ), the AlH 3 sample undergoes an ultra-fast reaction and generates a large amount of plasma. The expansion of the plasma pushes the surrounding air to form a supersonic shock wave and propagates forward. The shock wave propagation velocity of AlH 3 is 690.99 m/s in the range of 2.1–12.35 μs, and the higher the laser energy, the faster the shock wave propagation velocity. This study provides the basis for the application of AlH 3 . Graphical Abstract
研究领域:
氢存储材料
·
推进剂
·
高能材料
·
材料科学
·
化学工程
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 9
·6366-6377
·
IF 2.993
Li Wenqi,Ding Xingeng,Meng Cheng,Ren Chunrong,Wu Huating,Yang Hui
Rare earth phosphates (REPO 4 ) are considered as promising materials to immobilize the high-level radioactive waste. In the paper, Gd 1− x Yb x PO 4 ( x = 0, 0.1, 0.2, 0.4, 0.6, 0.8 and 1.0) series were prepared via the solid-state reaction using Gd as the surrogate for minor actinide Am and Cm, and the structure, phase transformation and morphology were characterized by XRD, Raman, TEM and SEM. With the calcination temperature ranging from 1200 to 1500 °C, the coexisted phases of monazite- and xenotime-type structure are observed in Gd 0.9 Yb 0.1 PO 4 . The monophasic xenotime-type Gd 0.9 Yb 0.1 PO 4 is obtained at 1600 °C. The monazite → xenotime transformation of Gd 1− x Yb x PO 4 depends on the substitution of Gd 3+ by Yb 3+ ions. With the decrease in Gd 3+ content, the gradual changes of FWHM and the hypsochromic shift of P-O symmetrical stretching vibration (Vs) are observed in the Raman spectra, indicating that the distortion of PO 4 tetrahedra occurs during the phase transformation process. The chemical durability test is measured by the ASTM product consistency test leaching method, and the normalized mass loss (NL Gd ) of Gd and (NL Yb ) of Yb is extremely low and shown in the order of 10 −6 –10 −7 g/m 2 for all the ceramics.
研究领域:
材料科学
·
核废料管理
·
固态化学
·
辐射化学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Yankun Xiong,Lijun Jin,He Yang,Yang Li,Haoquan Hu
Aromatic skeleton structure of Naomaohu (NMH) coal was investigated by a step-wise oxidation degradation and XRD , Raman and XPS characterization. Coal was first oxidized with H 2 O 2 to result in breakage of only bridged bonds and side chains, then the oxidation residue was further degraded through controlling alkali-oxygen (A-O) oxidation to avoid ring-open of polyaromatics and the conversion of coal sample exceeded 97.4 wt%. Synchronous fluorescence spectrometry (SFS) analysis of the oxidation products inferred that the aromatic structures in NMH coal mainly involve 1–4 rings compounds, among which single-ring structures are dominant accounting for 54.4 mol%. The results of XRD, Raman and XPS showed that NMH coal has a turbostratic structure, an intermediate state between the amorphous state and graphite, comprised by amorphous carbons and orderly aromatic clusters. The heteroatoms mainly exist in the forms of carbonyl, hydroxyl , pyrrolic nitrogen, mercaptan or thiophenol , thiophene , sulfoxide and sulfone . A simplified model of coal skeleton structure was proposed based on the complementary information from various techniques. Moreover, SFS analysis of A-O oxidation products clearly exhibits the gradual cracking process of polyaromatics, which provides an efficient method for controllable production of benzene carboxylic acids by preventing excessive or incomplete oxidation.
研究领域:
煤化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Faqiang Shi,Zhonghua Li,Limeng Liu,Jiandong Wu,Jinfu Ma,Yujin Wang
In previous works, it was found hard to synthesize “phase pure” ζ-Ta 4 C 3-z at relatively low temperatures even by prolonged heating, though ζ-Ta 4 C 3-z was believed stable till decomposition at ~2130°C. When the samples were subjected to TEM , vast richness of locally disordered structures in close relation with stacking of the close-pacted Ta-atom planes was observed. Although kinetic factors including diffusion of C atoms/vacancies and re-stacking of the Ta-atom planes explain the densely disordered structures, the richness of local disorders is a scenario that shows cohabitant of the cubic, rhombohedral, and hexagonal structures in a single grain, i.e. formation of a “hybrid grain” consisted of the three symmetries, indicating a transitional or intermediate stage before complete formation of the final phase of rhombohedral ζ-Ta 4 C 3-z . This time tantalum carbide ceramics TaC x with C:Ta atomic ratios x = 0.66 and 0.7 were prepared by reaction hot pressing of TaC and Ta powder mixtures. 5–30 mol% Cu/Ag additives and heat treatments were used to reproduce “hybrid grains” to facilitate further TEM and HRTEM observations on the disordered hybrid grains to argue for the transitional/intermediate stage. The cohabitant cubic, rhombohedral, and hexagonal structures in single grains may also help explain the difficulty in identification of the various phases by XRD in the transitional/intermediate stage of ζ-Ta 4 C 3-z reaction. Microstructural evolution and fracture toughness of the composites were also investigated.
研究领域:
材料科学
·
陶瓷
·
纳米材料
·
固体化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Likun Chen,Kewen Xing,Qikai Shentu,Yifei Huang,Weiyang Lv,Yuyuan Yao
Developing single-atom Fenton-like catalysts with the maximum utilization of active sites present an attractive potential in environmental remediation. Herein, the single-atom Fe and N co-doped hollow carbon microsphere loaded g-C 3 N 4 catalyst (HFeNC-g-C 3 N 4 ) was prepared by an innovative cascade anchoring strategy using polystyrene as the hard template, iron phthalocyanine, polydopamine and urea as the Fe, N and C precursor, in which the in-situ generated g-C 3 N 4 could not only effectively anchor Fe atom to create the well-dispersed Fe-N x active sites, but also accelerate the electron transfer in peroxymonosulfate (PMS) activation. Taking advantages of such sequential protecting strategy, the as-synthesized HFeNC-g-C 3 N 4 catalyst with single-atom Fe-N x active sites, verified by XRD , XPS and HAADF-STEM, could work as an efficient Fenton-like catalyst for PMS activation, which achieved almost 100% removal of 4-chlorophenol (4-CP) in 5 min with the turnover frequency calculated to be 34.6 times higher than that of the homogeneous Fe 2+ catalyst. The mechanism of O 2 •- dominated radical combined with nonradical 1 O 2 pathway was confirmed by quenching experiments and ESR analysis, which might be interrelated to the improvement of pH adaptability and interference immunity of HFeNC-g-C 3 N 4 /PMS system. Overall, the present findings provided an innovation strategy for the synthesis of excellent single-atom Fe based catalyst in wastewater purification.
研究领域:
环境科学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Hengli Qian,Guanjie Yu,Qidong Hou,Yifan Nie,Chuanyunlong Bai,Xinyu Bai,Haozhi Wang,Meiting Ju
To achieve efficient degradation of pharmaceutical and personal care products (PPCPs), dual reaction centers [email protected] photo-Fenton catalysts with high-speed electron transmission channel were designed through surface hydroxyl-induced assembly. In [email protected] catalytic system, the photocatalysis center of ZnO and Fenton catalytic center of FePc were formed simultaneously. Concept and process for the control of hydroxyl groups to construct a dual reaction center [email protected] photo-Fenton catalyst were verified ingeniously based on the density functional theory (DFT) analysis and experimental results. A series of catalysts, including ZIF-8 (400 ℃-N 2 ), FePc (400 ℃-N 2 ), ZIF-8 (400 ℃)-FePc (400 ℃) and [email protected] were prepared and characterized by XRD, FTIR, TEM, BET, XPS, PL and DRS, respectively. The [email protected] catalyst showed superior performance for the photo-Fenton degradation of ibuprofen, affording degradation rate larger than 90 % within just 10 min under simulateed sunlight. The excellent performance of [email protected] catalyst is mainly attributed to the synergistic effect between dual reaction centers of [email protected] This work provides a novel method to construct dual reaction centers [email protected] catalyst with efficient photo-generated electrons transmission link and to strengthen the synergistic effect of dual reaction centers.
研究领域:
环境化学
·
催化
·
材料科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 15
·12467-12475
·
IF 2.22
Xie Xinxin,Wang Hui,Zhou Yanping,Huang Kama
Microwave-assisted reduction of graphene oxide (GO) has been reported to be very effective in producing high-quality reduced graphene oxide (rGO) and its composites. However, either pretreatment (e.g., heating) or an external trigger (e.g., copper wire) is required to initiate the process due to the poor microwave absorption ability of GO. In this work, we report a one-step self-triggered microwave-arcing approach for synthesizing rGO composites (NiCo/rGO) for the first time. Evidenced by permittivity value, the synergic microwave absorption between GO and the metal nitrate salts is found to play an important role in initiating the process. From XRD, Raman, XPS and TEM results, it is proposed that mildly reduced rGO is firstly formed after 10 s, which further enables stronger microwave absorption to facilitate the complete reduction of GO as well as formation of well-crystallized NiCo nanoparticles about 10 nm after 90 s. The as-synthesized product shows a minimum refection loss value of − 44.48 dB with an absorption bandwidth of 3.66 GHz at 4.5 mm.
研究领域:
材料科学
·
纳米技术
·
电磁材料
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2018
·
IF 2.826
Ding Chen,Peng-fei Feng,Fu-hua Wei
Fe-based metal-organic frameworks(Fe(III)-MOFs)were synthesized by Fe 2 (SO 4 ) 3 and trimesic acid using microwave-assisted ball milling method. The structure of the Fe(III)-MOFs was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The thermostability of the MOFs was analyzed by thermogravimetric analysis (TGA). Fe(III)-MOFs were added in aqueous solutions to remove organic dyes. The removal efficiencies of Orange II, CR and MB reached 95.9%, 98.7%, 95.7% respectively at 10℃ and reached 97.7%, 99.7%, 97.5% respectively at 35℃ in 300 min.
研究领域:
材料科学
·
环境科学
·
化学
✓ 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）