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Xiong Wen David Lou - One of the best experts on this subject based on the ideXlab platform.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal Carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and Molybdenum-based polyoxometalates guest, mesoporous Molybdenum Carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:There is extensive research into non-platinum electrocatalysts for hydrogen evolution. Here, the authors report a Molybdenum Carbide catalyst, prepared via the carburization of a copper metal-organic framework host/Molybdenum-based polyoxometalates guest system, and demonstrate its catalytic activity.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal Carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and Molybdenum-based polyoxometalates guest, mesoporous Molybdenum Carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts. There is extensive research into non-platinum electrocatalysts for hydrogen evolution. Here, the authors report a Molybdenum Carbide catalyst, prepared via the carburization of a copper metal-organic framework host/Molybdenum-based polyoxometalates guest system, and demonstrate its catalytic activity.
Bao Yu Xia - One of the best experts on this subject based on the ideXlab platform.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal Carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and Molybdenum-based polyoxometalates guest, mesoporous Molybdenum Carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:There is extensive research into non-platinum electrocatalysts for hydrogen evolution. Here, the authors report a Molybdenum Carbide catalyst, prepared via the carburization of a copper metal-organic framework host/Molybdenum-based polyoxometalates guest system, and demonstrate its catalytic activity.
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porous Molybdenum Carbide nano octahedrons synthesized via confined carburization in metal organic frameworks for efficient hydrogen production
Nature Communications, 2015Co-Authors: Bao Yu Xia, Xiong Wen David LouAbstract:Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal Carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and Molybdenum-based polyoxometalates guest, mesoporous Molybdenum Carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts. There is extensive research into non-platinum electrocatalysts for hydrogen evolution. Here, the authors report a Molybdenum Carbide catalyst, prepared via the carburization of a copper metal-organic framework host/Molybdenum-based polyoxometalates guest system, and demonstrate its catalytic activity.
Brian M. Leonard - One of the best experts on this subject based on the ideXlab platform.
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Iron-Doped Molybdenum Carbide Catalyst with High Activity and Stability for the Hydrogen Evolution Reaction
Chemistry of Materials, 2015Co-Authors: Brian M. LeonardAbstract:Molybdenum-based materials have been widely investigated recently as promising alternatives to platinum for catalyzing the hydrogen evolution reaction (HER). Molybdenum Carbide is one of the most studied transition-metal Carbides because of its cheap price, high abundance, good conductivity, and catalytic activity. In order to further improve the catalytic activity of Molybdenum Carbide, some modifications have been applied. In this paper, a wide range of magnetic iron-doped Molybdenum Carbide (Mo2–xFexC) nanomaterials were synthesized by a unique amine–metal oxide composite method. The amount of iron dopants was controlled by setting different iron/Molybdenum ratios in the precursors. Iron-doped Molybdenum Carbide nanomaterials were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, Raman microscopy, and X-ray photoelectron spectroscopy. Electrocatalytic HER tests were used to demonstrate the catalytic activity upon addition ...
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Multiple Phases of Molybdenum Carbide as Electrocatalysts for the Hydrogen Evolution Reaction
Angewandte Chemie, 2014Co-Authors: Yagya N. Regmi, Brian M. LeonardAbstract:Molybdenum Carbide has been proposed as a possible alternative to platinum for catalyzing the hydrogen evolution reaction (HER). Previous studies were limited to only one phase, β-Mo2C with an Fe2N structure. Here, four phases of Mo-C were synthesized and investigated for their electrocatalytic activity and stability for HER in acidic solution. All four phases were synthesized from a unique amine–metal oxide composite material including γ-MoC with a WC type structure which was stabilized for the first time as a phase pure nanomaterial. X-ray photoelectron spectroscopy (XPS) and valence band studies were also used for the first time on γ-MoC. γ-MoC exhibits the second highest HER activity among all four phases of Molybdenum Carbide, and is exceedingly stable in acidic solution.
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crystal structure and morphology control of Molybdenum Carbide nanomaterials synthesized from an amine metal oxide composite
ChemInform, 2014Co-Authors: Cheng Wan, Nicole A Knight, Brian M. LeonardAbstract:Molybdenum Carbide nanomaterials are synthesized by thermal decomposition (625—900 °C) of precipitates obtained from mixtures of (NH4)6Mo7O24 and an amine in water (pH <3 adjusted with HCl, 50 °C, 2.5 h).
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crystal structure and morphology control of Molybdenum Carbide nanomaterials synthesized from an amine metal oxide composite
Chemical Communications, 2013Co-Authors: Cheng Wan, Nicole A Knight, Brian M. LeonardAbstract:Multiple phases of Molybdenum Carbide have been synthesized using a unique amine-metal oxide composite material. By combining Molybdenum oxide and an amine, a templated precursor is formed which can be thermally decomposed to form Molybdenum Carbide with control over the structure and morphology of the nano-sized products.
Abuliti Abudula - One of the best experts on this subject based on the ideXlab platform.
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hydrogen production by steam reforming of biomass tar over biomass char supported Molybdenum Carbide catalyst
International Journal of Hydrogen Energy, 2015Co-Authors: Malinee Kaewpanha, Katsuki Kusakabe, Guoqing Guan, Xiaogang Hao, Zhonglin Zhang, Prasert Reubroychareon, Abuliti AbudulaAbstract:Abstract Catalytic steam reforming of tar derived from Japanese cedar pyrolysis was investigated over a prepared biomass char supported Molybdenum Carbide (Mo2C/BC) catalyst in a fixed-bed reactor. Mo2C/BC was prepared by in-situ solid state reaction, and characterized by XRD and SEM to study the effects of carburization temperature and Mo loading amount on Mo2C formation. The results show that Mo2C/BC catalyst was successfully prepared at a relatively low carburization temperature of 800 °C and the initial Mo loading amount for the preparation of this catalyst should be lower than 30 wt.%. The Mo2C/BC showed a good catalytic activity for the steam reforming of tar derived from biomass. In the case of Mo2C/BC with a Mo loading of 20 wt.%, the highest H2 yield was obtained, which is about 5 times higher than that of non-catalytic test. Mo2C/BC could be a promising catalyst in steam gasification of biomass to remove tar and produce H2-rich gas.
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catalytic activity and stability of nickel modified Molybdenum Carbide catalysts for steam reforming of methanol
Journal of Physical Chemistry C, 2014Co-Authors: Guoqing Guan, Katsuki Kusakabe, Xiaogang Hao, Patchiya Phanthong, Wei Huang, Atsushi Tsutsumi, Abuliti AbudulaAbstract:Molybdenum Carbides were modified by nickel with different doping amounts by using a temperature-programmed reaction (TPRe) process and used for steam reforming of methanol (SRM). XRD analysis results indicated that the β-Mo2C phase was easily formed in Ni-modified Carbide samples. The doping amount of Ni had great effect not only on the activity of the Molybdenum Carbide catalyst, but also on the catalyst stability. For relatively lower Ni doping amounts, i.e., Ni/Mo molar ratio = 0.8/99.2 to 2.4/97.6, the catalysts exhibited almost the same methanol conversion in the reaction temperature range. Meanwhile, when the Ni/Mo molar ratio was over 5/95, the catalytic activity was decreased greatly. Furthermore, Ni–Mo2C with Ni/Mo molar ratios of 1.6/98.4 and 2.4/97.6 showed longer term stability than other samples. Compared with the pure β-Mo2C and other iron group element modified Carbide samples, the Ni-modified one showed higher catalytic activity and stability. The fresh and spent catalysts were characteri...
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Low-temperature steam reforming of methanol to produce hydrogen over various metal-doped Molybdenum Carbide catalysts
International Journal of Hydrogen Energy, 2014Co-Authors: Yufei Ma, Katsuki Kusakabe, Zhongde Wang, Guoqing Guan, Abuliti AbudulaAbstract:Abstract Various transition metals (M = Pt, Fe, Co, and Ni) were selected to support on Molybdenum Carbides by in-situ carburization metal-doped Molybdenum oxide (M-MoOx) via temperature-programmed reaction (TPR) with a final temperature of 700 °C in a reaction gas mixture of 20% CH4/H2. XRD analysis results indicated that β-Mo2C phase was formed in the case of Fe, Co, or Ni doping while α-Mo2C phase was appeared with the β-MoC1−x phase in the case of Pt doping. With the increase in Pt doping amount, more α-MoC1−x phase was produced. As-prepared metal doped Molybdenum Carbides were investigated as alternative catalysts for the steam reforming of methanol. Comparing with the undoped Molybdenum Carbide such as β-Mo2C, metal-doped one showed higher methanol conversion and hydrogen yield. It is found that Pt doped Molybdenum Carbide had the highest catalytic activity and selectivity among the prepared catalysts and methanol conversion reached 100% even at a temperature as low as 200 °C, and remained a long-time stability with a stable methanol conversion.
J L Figueiredo - One of the best experts on this subject based on the ideXlab platform.
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Molybdenum Carbide nanoparticles on carbon nanotubes and carbon xerogel low cost cathodes for hydrogen production by alkaline water electrolysis
Chemsuschem, 2016Co-Authors: Biljana Sljukic, D M F Santos, Milica Vujkovic, Luis Amaral, Raquel P Rocha, C A C Sequeira, J L FigueiredoAbstract:Low-cost Molybdenum Carbide (Mo2C) nanoparticles supported on carbon nanotubes (CNTs) and on carbon xerogel (CXG) were prepared and their activity for the hydrogen evolution reaction (HER) was evaluated in 8 m KOH aqueous electrolyte at 25–85 °C. Measurements of the HER by linear scan voltammetry allowed us to determine Tafel slopes of 71 and 74 mV dec−1 at 25 °C for Mo2C/CNT and Mo2C/CXG, respectively. Stability tests were also performed, which showed the steady performance of the two electrocatalysts. Moreover, the HER kinetics at Mo2C/CNT was enhanced significantly after the long-term stability tests. The specific activity of both materials was high, and a higher stability was obtained for the activated Mo2C/CNT (40 A g−1 at −0.40 V vs. the reversible hydrogen electrode).
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Molybdenum Carbide nanoparticles on carbon nanotubes and carbon xerogel low cost cathodes for hydrogen production by alkaline water electrolysis
Chemsuschem, 2016Co-Authors: Biljana Sljukic, D M F Santos, Milica Vujkovic, Luis Amaral, Raquel P Rocha, C A C Sequeira, J L FigueiredoAbstract:Low-cost Molybdenum Carbide (Mo2C) nanoparticles supported on carbon nanotubes (CNTs) and on carbon xerogel (CXG) were prepared and their activity for the hydrogen evolution reaction (HER) was evaluated in 8 m KOH aqueous electrolyte at 25–85 °C. Measurements of the HER by linear scan voltammetry allowed us to determine Tafel slopes of 71 and 74 mV dec−1 at 25 °C for Mo2C/CNT and Mo2C/CXG, respectively. Stability tests were also performed, which showed the steady performance of the two electrocatalysts. Moreover, the HER kinetics at Mo2C/CNT was enhanced significantly after the long-term stability tests. The specific activity of both materials was high, and a higher stability was obtained for the activated Mo2C/CNT (40 A g−1 at −0.40 V vs. the reversible hydrogen electrode).