FUEL
·
2018
·
IF 4.908
Fei Wang,Jianchun Jiang,Kui Wang,Qiaolong Zhai,Hao Sun,Peng Liu,Junfeng Feng,Haihong Xia,Jun Ye,Zhengxiang Li,Fanglin Li,Junming Xu
The activated carbon supported Mo 2 C and W 2 C were synthesized successfully for hydrotreatment of fatty acids to produce diesel-like hydrocarbons. The carburization temperature, carburization gas as well as metal loading amount were studied. High carburization temperature was feasible for W 2 C/AC, but not for Mo 2 C/AC because it resulted in agglomeration of molybdenum compound and destruction of catalyst. Under hydrotreatment condition (360 °C, H 2 3.0 MPa, 3.0 h) the conversion achieved 96.01% over Mo 2 C/AC prepared at 700 °C and 54.88% over W 2 C/AC prepared at 900 °C respectively. During carburization both flowing nitrogen and hydrogen were proper for formation of W 2 C/AC, while only flowing hydrogen was appropriate for Mo 2 C/AC. The hydrotreatment parameters (reaction temperature and reaction time) were also investigated. The high reaction temperature and long reaction time facilitated the conversion of fatty acids, meanwhile the high reaction temperature simultaneously improved the cracking degree of products.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2014
·
IF 0
Jin Jia,Yuan Yuan Zhu,Ya Fei Zhang,Ruo Yu Chen,Bao Lin Xing,Ai Guo Zhou
Carbide-derived carbons (CDCs) are produced from carbides by removing non-carbon elements in the process of selective etching. In this paper, CDC was prepared from TiC by chlorination at the temperature range of 600~1100°C. In the chlorinating process, carbide-derived carbon with different microstructure was obtained by controlling the reaction temperature. The structures of CDC were revealed with X-ray diffraction and Raman spectroscopy. The morphologies of CDC were analyzed by scanning electron microscope. From X-ray diffraction analysis, the CDC obtained from TiC in this experiment mainly consisted of amorphous carbon. Basing on scanning electron microscopy, carbide-derived carbon from TiC maintained the shape and size of TiC particles. Keywords: Carbide-derived carbons; chlorination; TiC
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yingjie Ding,Chaoyang Zhu,Zezhong Xu,Hongdian Lu,Kunhong Hu,Ping Chen,Wei Yang,Jinsong Xie
Given the scarcity of freshwater and the abundance of seawater resources, electrochemical seawater electrolysis is a more competitive and efficient method for hydrogen production, but it still remains challenging due to the lack of catalysts with efficient activity and corrosion resistance. Among various strategies to enhance catalytic activity, bimetallic carbides have emerged as a promising approach due to their synergistic effects and tunable electronic properties. In this paper, the Fe 3 C-Mo 2 C structure embedded on carbon nanofibers (referred to as Fe 3 C-Mo 2 C@CNFs/0.15) was successfully synthesized by the electrospinning-pyrolysis process. Fe 3 C-Mo 2 C@CNFs /0.15 exhibited superior OER activity in both alkaline freshwater and simulated seawater, with low overpotentials of 228 mV and 247 mV at 10 mA cm -2 , and Tafel slopes of 34.0 mV dec -1 and 37.0 mV dec -1 , respectively, due to its abundant active sites, high conductivity, and fast kinetics. Moreover, the electrolytic cell with Fe 3 C-Mo 2 C @CNFs/0.15 as both cathode and anode achieved 10 mA cm -2 at low cell voltages of 1.65 V and 1.69 V, respectively. It also demonstrated excellent long-term stability up to 48 h and corrosion resistance. This work not only provides a novel strategy for designing low-cost, high-performance OER electrocatalysts but also paves the way for practical applications in seawater electrolysis for sustainable hydrogen production.
研究领域:
材料科学
·
能源化学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Yuxuan Zhang,Jun Luo,Biao Feng,Hongxia Xu,Yuanyuan Sun,Xueyuan Gu,Xin Hu,Mu Naushad,Bin Gao,Hongqiang Ren
MXenes are considered as an emerging class of two-dimensional (2D) adsorbent for various environmental applications. In this work, two different morphologies of Ti 3 C 2 T x MXene (multilayer (ML-Ti 3 C 2 T x ) and delaminated titanium carbide (DL-Ti 3 C 2 T x )) were prepared through mild in situ HF etching and further delamination . The structural differences between the two were explored with a focus on their effects on the performance and mechanism of removing heavy metals from water. In comparison to ML-Ti 3 C 2 T x , DL-Ti 3 C 2 T x had more oxygen-containing functional groups, higher specific surface area (19.713 vs. 8.243 m 2 /g), larger pore volume (0.135 vs. 0.040 cm 3 /g), higher maximum Pb(II) adsorption capacity (77.0 vs. 56.68 mg/g), but lower maximum Cu(II) adsorption capacity (23.08 vs. 55.46 mg/g). Further investigation revealed that the removal of Pb(II) by the MXenes was mainly controlled through electrostatic attraction and surface complexation mechanisms, while Cu(II) was removed mainly through surface reduction by Ti-related groups. Because delamination of ML-Ti 3 C 2 T x increased the surface area and surface functional groups, DL-Ti 3 C 2 T x became a better sorbent for Pb(II) in water. During sonication, however, delamination inevitably led to partial oxidation of Ti 3 C 2 T x nanosheets and thus weakened the reducing ability of DL-Ti 3 C 2 T x for Cu(II) in water. Nevertheless, both ML- and DL-Ti 3 C 2 T x not only exhibited excellent heavy metal adsorption capacity under different solution conditions, but also showed good reusability. Findings of this study indicate that Ti 3 C 2 T x MXenes are promising adsorbents for treating heavy metal pollutants in water.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
He Sun,Jiaming Chen,Yusheng Yang,Min Qiu,Milin Zhang
A low-grade ore containing 4 % niobium and 7 % titanium has been extracted from Bayan Obo tailing, but its potential has not been fully utilized. This study aims to recover the niobium and titanium elements from this low-grade ores in the form of their carbides. The process involves reducing niobium and titanium to (Nb,Ti)C through a carbothermal process. During this process, iron and silicon are also reduced to Fe-Si intermetallic compounds, allowing (Nb,Ti)C to diffuse into them. Subsequently, selective electrochemical oxidation is used to separate (Nb,Ti)C from the Fe-Si intermetallic compounds in an aqueous ferrous sulfate solution. The Fe-Si intermetallic compounds are first oxidized to the Fe 3 Si phase, and then to the Fe 5 Si 3 phase in the solution with pH 0.35. The (Nb,Ti)C/matrix interfaces are identified as the preferred site of electrochemical pitting corrosion. By exploiting the electrochemical oxidation reaction of iron in the matrix, (Nb,Ti)C powders are separated along these interfaces. The by-products of this process are FeSi alloys, which are evaluated for their electrocatalytic properties in oxygen evolution reactions. It is found that the Fe 5 Si 3 alloy by-product exhibits good electrocatalytic activity and kinetics in the oxygen evolution reaction, demonstrating its potential for practical applications.
研究领域:
冶金学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 11
·9338-9343
·
IF 3.289
X. W. Chen,S. M. Dong,Y. M. Kan,H. J. Zhou,J. B. Hu,Y. S. Ding
Boron carbide (B4C) powder was synthesized by heating a gel precursor with pyrolysis and carbothermal processes. The gel precursor was prepared by the condensation reaction of boric acid (H3BO3) and polyvinyl alcohol (PVA) at a weight ratio of 1/2 with the addition of various amounts of glycerine. The effects of glycerine addition on the synthesis of B4C powder were studied. It was observed that glycerine could promote the condensation reaction and resulted in a pyrolyzed precursor with a much finer distribution of B2O3 in the carbon matrix. This led to a significant reduction of residual free carbon in the B4C powder. Moreover, the morphology of the B4C powder was also found to be closely related to the glycerine addition.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 21
·期 1
·2406022
·
IF 13
Jiamin Zhao,Meimei Kou,Qing Yuan,Ying Yuan,Jinsheng Zhao
Tungsten carbide (WC x ) is a promising alternative to platinum catalysts for hydrogen evolution reaction (HER). However, strong tungsten–hydrogen bond hinders hydrogen desorption while favoring H + reduction, thus limiting HER kinetics. Inspired by the phenomenon of hydrogen spillover in heterogeneous catalysis, a ruthenium (Ru) doped-driven activated hydrogen migration from WC x surface to Ru is reported. This approach achieved high activity with an ultralow overpotential of 9.0 mV at 10 mA·cm −2 and superior stability at an industrial-grade current density of 1.0 A·cm −2 @ 1.65 V. In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and operando electrochemical impedance spectra revealed that this exceptional hydrogen production—which surpasses that of previously reported Pt/C catalysts—is attributable to the outstanding ability of WC x to induce water dissociation and hydrogen spillover from WC x to Ru surface. During the HER process, the rigid interfacial water network negatively affected the HER efficiency under alkaline conditions. The WC x sites disrupted this rigid structure, facilitating the contact between activated hydrogen (H * ) and WC x sites. Subsequently, H * migrates to Ru surface, where hydrogen recombination occurs to produce H 2 . This work paves a new avenue for the construction of coupled catalysts at the atomic scale to facilitate HER electrocatalysis.
研究领域:
电化学
·
催化材料
·
能源科学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 24
·16438-16445
·
IF 3.3
Zhiwei Yang,Lijuan Dong,Qian Chen,Zeyi Wang,Jiacheng Cao,Mengwei Dong,Jian Wang,Jian Zhang,Xiao Huang
Although titanium-based MXenes have been widely reported for gas sensing, the effect of crystal stoichiometric variations on the sensing properties has been rarely reported. Herein, stoichiometric polymorphs of titanium carbide MXenes (i.e., Ti3C2Tx and Ti2CTx) loaded with Pd nanodots (NDs) prepared by photochemical reduction were investigated for room-temperature H2 sensing. Interestingly, we found that Pd/Ti2CTx exhibited greatly enhanced sensitivity to H2, along with faster response and recovery rates compared to Pd/Ti3C2Tx. The H2 adsorption induced resistance change in Pd/Ti2CTx was higher than that of Pd/Ti3C2Tx due to the more effective charge transfer at the heterointerface of Pd/Ti2CTx, which was confirmed by shifts of binding energies and theoretical calculation results. We hope this work could be helpful to design more high-performance MXene-based gas sensors.
研究领域:
材料科学
·
传感器技术
·
表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhenzhong Liu,Suyue Luo,Xinran Yin,Shuo Zhang,Minghui Guo
The present work effectively achieved the production of a self-supporting electrode with high efficiency. The process involves incorporating nickel and molybdenum carbide (Mo 2 C) phases within the channels of wood through high-temperature calcination at the nanoscale. The obtained carbonized wood (CW) possesses low tortuosity and three-dimensional vertical channels, providing an excellent substrate for the preparation of Ni-Mo 2 C/N-CW electrodes. Mo 2 C is well known for its considerable potential as a non-precious metal electrocatalyst with enhanced catalytic activity. The successful doping of nickel and nitrogen into molybdenum carbide not only promotes the formation of β-Mo 2 C, but also improves the electron transfer rate and mass diffusion pathway. Consequently, the Ni-Mo 2 C/N-CW electrode exhibits excellent performance in the hydrogen and oxygen evolution reactions (HER and OER, respectively). Only voltages of 89 and 253 mV are required to achieve a current density of 10 mA cm −2 , respectively. When the Ni-Mo 2 C/N-CW catalyst is used as both cathode and anode during hydrolysis, current densities of 10 and 100 mA cm −2 can be achieved with excellent durability and stability at voltages of 1.56 and 1.72 V, respectively. The distinctive porous structure of the wood substrate is of crucial importance for promoting the adsorption and dissociation of water molecules, enhancing the catalytic performance. In addition, the present material exhibits advantageous characteristics, including a high specific surface area and a significant number of adsorption sites, making it a very promising candidate for applications involving the adsorption of dyes, such as rhodamine B (RhB).
研究领域:
材料科学
·
电化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yang Wang,Qiang Liu,Biao Zhang,Haoqian Zhang,Yicheng Jin,Zhaoxin Zhong,Feng Ye,Wen Wang
The architectures of porous B 4 C scaffolds play a pivotal role in the performance of their infiltrated composites for multiple applications. Here, we use gelation-freeze-drying approach to creating the porous B 4 C scaffolds with oriented channels, which are promising and relatively untested freeze-cast constructs. Addition of gelatin alters not only the porosity and shrinkage but also the pore size and morphology of the scaffolds. Specifically, as gelatin contents increase from 0 to 5 wt%, the porosity, closed porosity, and volume shrinkage range from 74.53 to 73.27%, 0.28–0.65% and 1.95–3.96%, respectively; the increased wavelength and lamellar thickness can be attributed to the enhancement in viscosity. Importantly, raised gelatin contents lead to the reduced pore aspect ratio triggering the transformation from lamellae with a high aspect ratio to ellipse shaped morphologies that contribute to the improved compressive strength ranging from 0.7 to 4.4 MPa. The freeze-cast B 4 C scaffolds with tailored performance by varying gelatin contents widen the application scopes of bioinspired composites.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yaqiong Du,Fengling Wang,Meihua Hu,Qianku Hu,Aiguo Zhou
Mo 2 Ga 2 C is a novel member of MAX phases, which is a family of ternary carbide/nitride with layered structure. The stability and wettability of Mo 2 Ga 2 C in molten metals are crucial for the application of Mo 2 Ga 2 C in the field of composite materials. In this work, the stability and wettability of Mo 2 Ga 2 C in three molten metals (Pb, Sn and Zn) were investigated. Mo 2 Ga 2 C was mixed with metal powders and annealed at different temperatures under vacuum. At 700 °C, Mo 2 Ga 2 C was not stable in any of the three molten metals. The decomposition of Mo 2 Ga 2 C was affected by the type of metal matrix as well as the reaction temperature. Mo 2 Ga 2 C decomposed at 550 °C in Pb, at 450 °C in Sn, or at 650 °C–750 °C in Zn. To characterized the wettability of these metals with Mo 2 Ga 2 C, the contact angle of molten metals with Mo 2 Ga 2 C at 650 °C were measured, which are 103° for Pb, 126° for Sn and 0° for Zn, respectively. Mo 2 Ga 2 C has good wettability with Zn and is not wetted by Pb and Sn.
研究领域:
材料科学
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 28
·期 1
·192
·
IF 4.927
Yunjie Huang,Yaqi Bao,Tieqi Huang,Chengzhi Hu,Haiou Qiu,Hongtao Liu
Molybdenum carbide is considered to be one of the most competitive catalysts for hydrogen evolution reaction (HER) regarding its high catalytic activity and superior corrosion resistance. But the low electrical conductivity and poor interfacial contact with the current collector greatly inhibit its practical application capability. Herein, carbon nanotube (CNT) supported molybdenum carbide was assembled via electrostatic adsorption combined with complex bonding. The N-doped molybdenum carbide nanocrystals were uniformly anchored on the surfaces of amino CNTs, which depressed the agglomeration of nanoparticles while strengthening the migration of electrons. The optimized catalyst (250-800-2h) showed exceptional electrocatalytic performance towards HER under both acidic and alkaline conditions. Especially in 0.5 M H2SO4solution, the 250-800-2h catalyst exhibited a low overpotential of 136 mV at a current density of 10 mA/cm2(η10) with the Tafel slope of 49.9 mV dec−1, and the overpotential only increased 8 mV after 20,000 cycles of stability test. The active corrosive experiment revealed that more exposure to high-activity γ-Mo2N promoted the specific mass activity of Mo, thus, maintaining the catalytic durability of the catalyst.Keywords:molybdenum carbide;carbon nanotube;electrocatalyst;hydrogen evolution reaction
研究领域:
材料科学
·
电化学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）