INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Kejing Wu,Junbo Wang,Yingming Zhu,Xueting Wang,Chunyan Yang,Yingying Liu,Changjun Liu,Houfang Lu,Bin Liang,Yongdan Li
The β-Mo2C on different carbon supports was prepared conveniently via direct H2 reduction or self-reduction for catalytic conversion of Kraft lignin into aromatic hydrocarbons, aromatic alcohols, and aromatic aldehydes. The β-Mo2C on macroporous carbon (MC) with large pore size exhibits the highest activity with aromatic yield of 0.543 g/g Kraft lignin at 280 °C for 3 h, resulting from the accessibility of lignin fragments to β-Mo2C. Mo, MoO2, and MoO3 possess relatively low activity. Higher calcination temperature is required to obtain β-Mo2C over graphite (Gr) support than MC and activated carbon (AC), and small grain size of Gr-supported catalysts is beneficial for high activity. The β-Mo2C on AC exhibits the highest selectivity to aromatic hydrocarbons, which are attributed to highly dispersed β-Mo2C in micropores.
研究领域:
催化化学
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材料科学
·
生物质转化
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 6
·4589-4600
·
IF 2.993
Tan Jiabin,He Xiaobo,Yin Fengxiang,Liang Xin,Chen Biaohua,Li Guoru,Yin Huaqiang
In this study, a β-Mo 2 C/N, P-co-doped carbon (NPC) catalyst with a porous structure of β-Mo 2 C nanoparticles loading on NPC matrix was prepared by vacuum-rotary evaporation and followed by a facile pyrolysis process for hydrogen evolution reaction (HER). The porous structure is beneficial for exposing more active sites and the mass transfer during the HER. In addition, the carbon matrixes with the highly doped N and P heteroatoms also provide their positive contributions to its high catalytic activity for HER. Owing to the advantages mentioned above, the optimized catalyst shows a small overpotential of 181 mV for driving a cathodic current density of 10 mA cm −2 , a low Tafel slope of 65.3 mV dec −1 and a high exchange current density of 1.5 × 10 −2 mA cm −2 during HER processes in acid electrolyte. The excellent performance of the β-Mo 2 C/NPC makes it a great potential candidate as the HER electrocatalyst.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 8
·7175-7184
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IF 4.987
Yang Chunyan,Zhang Liu,Zhu Yingming,Liu Yingying,Liu Changjun,Wu Kejing,Lu Houfang,Liang Bin
In this study, ordered mesoporous carbon materials are prepared to support β-Mo 2 C catalysts for conversion of Kraft lignin into aromatic monomers. Carbon supports with different porous structures are compared to discuss the critical role of ordered mesopores. The results show a volcano evolution of aromatic monomer yields with the increase in Mo contents over β-Mo 2 C supported on ordered mesoporous carbon, and a high aromatic yield of 0.576 g/g Kraft lignin is achieved at 280 °C for 3 h for only 10% Mo mass content. Dispersion of β-Mo 2 C and confinement of ordered mesopores contribute to the highest aromatic yield per unit Mo. The highly dispersed β-Mo 2 C on the surface of ordered mesoporous carbon exhibits the advances of confined environment and accessibility of lignin fragments to active β-Mo 2 C, resulting high activity of β-Mo 2 C for Kraft lignin decomposition.
研究领域:
材料科学
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化学工程
·
可再生资源转化
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产品关联
DOI
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 11
·8346-8353
·
IF 4.6
Qingshan Rong,Wei Ding,Guogang Liu,Xiangyu Fu,Yan Shi,Zhiqiang Zhang,Zhiwei Yao
In this study, we found that β-Mo2C prepared at different carbonization temperatures exhibited significantly different catalytic activities for the reverse water gas shift (RWGS) reaction. The β-Mo2C synthesized at 600 °C demonstrated notably higher activity compared to those prepared at 700 °C and 800 °C. This enhanced activity was likely attributed to its improved redox properties, which were primarily driven by a smaller crystallite size and the presence of MoxOCy species. Therefore, we proposed that the crystallite size and MoxOCy content were the key factors governing the RWGS activity of β-Mo2C. Clearly, both factors were strongly influenced by the carbonization temperature. Notably, the β-Mo2C prepared at 600 °C even outperformed Cu-doped β-Mo2C prepared at 700 °C under similar reaction conditions.
研究领域:
催化化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 14
·6054-6064
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IF 9.931
Lechen Diao,Jian Qin,Naiqin Zhao,Chunsheng Shi,Enzuo Liu,Fang He,Liying Ma,Jiajun Li,Chunnian He
Hollow β-Mo2C/N-doped carbon composite nanospheres constructed by mesoporous ultrathin carbon nanosheets anchored with ultrasmall β-Mo2C nanoparticles were synthesized through a facile green process. Nanobubbles generated by ethanol–water exchange were utilized as templates for the core, while the precipitates in the solution were directly adopted as the emulsion stabilizer and the shell. Upon the self-polymerization of dopamine, a robust shell consisting of the Mo–polydopamine complex was formed. The size of the as-obtained hollow Mo–polydopamine nanospheres can be tuned by varying the type of gas, which is proportional to the supersaturation of gas. These precursors of hollow Mo–polydopamine nanospheres were then converted into hollow β-Mo2C/N-doped carbon composite nanospheres by high-temperature carbonization treatment. The N-doped carbon matrix can act as an electron conductor and facilitate the prevention of the migration and aggregation of the Mo2C nanoparticles, while the ultrafine Mo2C nanoparticles can achieve maximum material utilization for hydrogen evolution electrocatalysis. In addition, the mesoporous 2D nanosheets combined with their constructed 3D hollow structures can expose numerous active catalytic sites while enabling free diffusion of the electrolyte and mass transfer. As a result, the hollow β-Mo2C/N-doped carbon composite nanospheres exhibit low overpotentials and robust cycling stability in both acidic and alkaline electrolytes.
研究领域:
材料科学
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电化学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2022
·
IF 6.562
Mingsheng Luo,Chenmeng Li,Qinglong Liu,Zhi Yang,Yatao Wang,Hongjuan Li
Direct hydrogenation of CO to alcohols through Fischer-Tropsch reaction process is taken great interest in recent years. In this study, a series of β-Mo 2 C/γ-Al 2 O 3 catalyst are prepared to investigate the influence of carbon and molybdenum precursor, calcination temperature, as well as the molar ratio of the carbon precursor to molybdenum precursor compounds on catalyst microstructures and the catalytic performance. The microstructure characteristics of the catalysts were examined with XRD, BET, ICP, SEM and CO-TPD. The performance test of the catalysts for syngas-to-alcohol was investigated in a fixed-bed reactor. Properly excessive amount of hexamethylenetetramine as carbon precursor calcined at a high temperature (≥700 ℃) favors the formation of high crystalline β-Mo 2 C on γ-Al 2 O 3 carrier. Catalysts with different amount of Mo were prepared to study the effect of active metal loading on microstructure and catalytic performance. The results show that the particle size of β-Mo 2 C and CO dissociation adsorption capacity, as well as the CO conversion increases with raised Mo loading. The selectivity of all higher alcohols reached the maximum when 25 % of Mo was loaded.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Qinglei Wu,Chenyang Shen,Chang-jun Liu
Molybdenum carbide is a promising support to tune the metal reactivity, which originates from the interaction between metal and support. In this work, Pd/β-Mo 2 C was prepared using a deposition-precipitation method for selective hydrogenation of acetylene. The high temperature calcination is employed to modulate the interaction between Pd and β-Mo 2 C. The Pd/β-Mo 2 C catalyst calcined at 600 °C exhibits significant promotion in selective hydrogenation, which shows 100 % acetylene conversion and 81.4 % ethylene selectivity at 160 °C. The activity promotion originates from the enhanced electronic metal-support interaction, which induces a shift of Pd 3d to higher binding energy. Besides, the Pd species become atomically dispersed after calcination. The changes in geometric and electronic structure suppress the formation of Pd hydrides, which consequently inhibits the excessive hydrogenation capacity of Pd. The structure variation also affects the adsorption of ethylene. No strong adsorbed ethylene (di-σ bonded ethylene) can be identified, which is conducive to the improvement of ethylene selectivity. Density functional theoretical (DFT) calculations confirm that Pd on β-Mo 2 C is positively charged. The desorption energy of C 2 H 4 * (0.78 eV) is significantly lower than that of further hydrogenation (1.45 eV), which explains the improved ethylene selectivity of the calcinated catalyst. The present study indicates calcination is an effective method to tune the activity of Pd/β-Mo 2 C for reactions beyond selective hydrogenation of acetylene.
研究领域:
催化
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化学工程
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材料科学
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理论化学
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DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2015
·
IF 3.615
Junmei Liang,Ranran Ding,Yulong Wu,Yu Chen,Kejing Wu,Yongqiang Meng,Mingde Yang,Yaowu Wang
Hydrotreatment of heteroatomic model compounds in microalgae-based bio-oils into diesel-like hydrocarbons was carried out over carbon nanotubes (CNTs)-supported β-Mo 2 C catalyst with superior activity and selectivity under a mild condition (≤200 °C). The results show that stearic acid and hexadecanamide can be completely converted into n -C 15 –C 18 alkanes over β-Mo 2 C/CNTs catalyst. The β-Mo 2 C/CNTs favors the pathway of hydrogenation–dehydration–hydrogenation to produce n -octadecane with an optimal yield of 91.24% at a lower temperature of 180 °C during hydrotreating process of stearic acid. The recycle tests demonstrate that the β-Mo 2 C/CNTs exhibits excellent stability, and can be reused for seven times consecutively without reduction of catalytic stability. Based on the determined products, a brief reaction pathway is proposed. Therefore, a novel approach to produce diesel-like hydrocarbons via catalytic hydrotreatment of microalgae-based bio-oils over β-Mo 2 C/CNTs is introduced, which provides a basic research as well as technical parameters for its further industrialization.
研究领域:
能源生物学
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催化化学
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产品关联
DOI
高影响因子
Carbon Energy
·
2023
·Vol. 5
·期 12
·e349
·
IF 20.5
Tianyu Gong,Yang Liu,Kai Cui,Jiali Xu,Linrui Hou,Haowen Xu,Ruochen Liu,Jianlin Deng,Changzhou Yuan
Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction (HER) performance is very important for large-scale and efficient electrolysis of water. Herein, a sandwich composite structure (designed as MS-Mo 2 C@NCNS) of β- Mo 2 C hollow nanotubes (HNT) and N-doped carbon nanosheets (NCNS) is designed and prepared using a binary NaCl–KCl molten salt (MS) strategy for HER. The temperature-dominant Kirkendall formation mechanism is tentatively proposed for such a three-dimensional hierarchical framework. Due to its attractive structure and componential synergism, MS-Mo 2 C@NCNS exposes more effective active sites, confers robust structural stability, and shows significant electrocatalytic activity/stability in HER, with a current density of 10 mA cm −2 and an overpotential of only 98 mV in 1 M KOH. Density functional theory calculations point to the synergistic effect of Mo 2 C HNT and NCNS, leading to enhanced electronic transport and suitable adsorption free energies of H* (Δ G H* ) on the surface of electroactive Mo 2 C. More significantly, the MS-assisted synthetic methodology here provides an enormous perspective for the commercial development of highly active non-noble metal electrocatalysts toward efficient hydrogen evolution.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Shuanghui Zeng,Xiangqun Zeng,Lan Jiang,Zhao Ding,Jiao-Jing Shao,Jie Zhao
s Developing efficient non-noble metal-based electrocatalysts for the hydrogen evolution reaction (HER) is urgently required for the large-scale electrolysis of water. Mo 2 C shows excellent HER catalytic activity. The construction of heterostructures by combining Mo 2 C and carbonaceous materials provides an effective strategy to modulate the electronic structure and hydrogen adsorption ability of molybdenum carbide . The β-Mo 2 C nanoparticles bundled on semiconducting carbon nanotubes (CNTs) with a Mott-Schottky heterojunction has been prepared in situ on the carbon cloth via a facile solvothermal and annealing process. Contributing to the synergistic effect of β-Mo 2 C and CNTs, the synthesized Mo 2 C/CNTs@CC electrode exhibits greatly enhanced HER catalytic activity with an overpotential of 123 mV to achieve a current density of −10 mA cm −2 , a Tafel slope of 51 mV dec −1 , and excellent durability. DFT calculations indicate that the CNTs donate electrons to β-Mo 2 C to enhance the coupling interfaces within β-Mo 2 C and CNTs and modify the electronic structure, resulting in a lower reaction barrier in the Volmer step and faster HER activities. This work provides a synthetic route to Mott-Schottky heterostructure Mo 2 C/CNTs with excellent HER catalytic activity.
研究领域:
材料科学
·
电化学
·
纳米技术
·
催化
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Xiangyong Zhang,Junchao Wang,Ting Guo,Tianying Liu,Zhuangzhi Wu,Luigi Cavallo,Zhen Cao,Dezhi Wang
Non-precious metal-based efficient electrocatalysts with superior activity and stability for the hydrogen evolution reaction (HER) are useful in solving energy and environmental crises. Herein, monodisperse inverse opal-like Mo x C (α-MoC 1-x /β-Mo 2 C) nanospheres were synthesized via a facile strategy to adjust the intrinsic activity and maximize the exposed active sites. In particular, the Mo x C-0.4 with the optimal composition of α-MoC 1-x /β-Mo 2 C (0.56/0.44) demonstrated a superior HER performance in 0.5 M H 2 SO 4 with a small Tafel slope of 48 mV dec −1 and remarkable stability. Such prominent performance not only benefits from the inverse opal-like structure that provides more active sites for HER, but also should be ascribed to the strong synergistic effect between α-MoC 1-x and β-Mo 2 C. Based on theoretical calculations, it is further verified that the synergistic effect of Mo x C-0.4 is originated from the optimization of interaction with the H* induced by the heterostructure. Furthermore, this work will broaden our vision for highly efficient hydrogen production by bridging the microscopic structure with macroscopic catalytic performance.
研究领域:
材料科学
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能源科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2019
·Vol. 31
·期 10
·105707
·
IF 3.399
Zijian Chen,Ting Guo,Zhuangzhi Wu,Dezhi Wang
As highly efficient non-precious metal-based catalysts for the hydrogen evolution reaction (HER), molybdenum carbides have attracted much attention over the phase and structure modification for the improvement of HER performances. In this work, a novel strategy is proposed to modulate phases of molybdenum carbides by boron doping, so that the HER performances can be well controlled. After B-doping, the HER activity of the as-prepared B30 catalyst is significantly enhanced with a much smaller Tafel slope of 78 mV dec−1 than that of the blank one (134 mV dec−1), which originates from the increased amount of active sites, enhanced turnover frequency of each active site and reduced electron transfer resistance. Moreover, this work could broaden our view of phase regulation and provide more possible perspectives for the application in other fields.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 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）