The Experts below are selected from a list of 75513 Experts worldwide ranked by ideXlab platform
Hongbin Dai - One of the best experts on this subject based on the ideXlab platform.
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effect of trapped hydrogen on the induction period of cobalt tungsten boron nickel foam catalyst in catalytic Hydrolysis Reaction of sodium borohydride
Catalysis Today, 2011Co-Authors: Hongbin Dai, Yan Liang, Ping WangAbstract:Abstract Calcination treatment is an important step in preparation of supported transition metal catalysts that are effective for promoting the Hydrolysis Reaction of sodium borohydride. We found that calcination treatment of cobalt–tungsten–boron/nickel foam catalysts results in the appearance of an induction period in their first time use, and the duration of which depends on the calcination temperature and atmosphere. Upon reusing the catalysts, the induction period completely disappeared. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and synchronous thermal analyses techniques were employed to study the mechanism underlying the induction period phenomenon. Our study results showed that the appearance/disappearance of the induction period should be correlated with the desorption/reabsorption of hydrogen in the catalysts.
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hydrogen bubbles dynamic template preparation of a porous fe co b ni foam catalyst for hydrogen generation from Hydrolysis of alkaline sodium borohydride solution
Journal of Alloys and Compounds, 2010Co-Authors: Yan Liang, Ping Wang, Hongbin DaiAbstract:By using a modified electroless plating method, a porous Fe-Co-B catalyst is prepared on Ni foam support in order to generate hydrogen from an alkaline sodium borohydride (NaBH(4)) solution. In this process, hydrogen bubbles originating from electroless deposition function as a dynamic template to form the porous catalyst. The effects of NaBH(4), NaOH concentration and Reaction temperature on the Hydrolysis Reaction kinetics are investigated. it has been found that an average hydrogen generation rate of 221 min(-1) g(-1) (Fe-Co-B) is achieved in a 15 wt.% NaBH(4) and 5 wt.% NaOH solution at 30 degrees C and the apparent activation energy of the Hydrolysis Reaction is determined to be 27 kJ mol(-1). The catalyst exhibits a high activity due to its porous structure, which facilitates the access of reactants to the surface active sites of catalyst. (C) 2009 Elsevier B.V. All rights reserved.
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high performance cobalt tungsten boron catalyst supported on ni foam for hydrogen generation from alkaline sodium borohydride solution
International Journal of Hydrogen Energy, 2008Co-Authors: Hongbin Dai, Ping Wang, Yan Liang, Xiangdong Yao, Thomas E Rufford, Huiming ChengAbstract:Low cost and catalytically effective transition metal catalysts are highly wanted in developing on-demand hydrogen generation system for practical onboard application. By using a modified electroless plating method, we have prepared a robust Co–W–B amorphous catalyst supported on Ni foam (Co–W–B/Ni foam catalyst) that is highly effective for catalyzing hydrogen generation from alkaline NaBH4 solution. It was found that the plating times, calcination temperature, NaBH4 and NaOH concentrations all exert considerable influence on the catalytic effectiveness of Co–W–B/Ni foam catalyst towards the Hydrolysis Reaction of NaBH4. Via optimizing these preparation and Reaction conditions, a hydrogen generation rate of 15 L/min g (Co–W–B) has been achieved, which is comparable to the highest level of noble metal catalyst. In consistent with the observed pronounced catalytic activity, the activation energy of the Hydrolysis Reaction using Co–W–B/Ni foam catalyst was determined to be only 29 kJ/mol. Based on the phase analysis and structural characterization results, the mechanism underlying the observed dependence of catalytic effectiveness on the calcination temperature was discussed.
Zhou Peng Li - One of the best experts on this subject based on the ideXlab platform.
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a review hydrogen generation from borohydride Hydrolysis Reaction
Journal of Power Sources, 2009Co-Authors: Zhou Peng LiAbstract:Abstract In this review, a convenient hydrogen generation technology based on sodium borohydride and water as hydrogen carriers has been summarized. The recent progresses in the development of the hydrogen generation from sodium borohydride Hydrolysis are reviewed. The NaBH4 Hydrolysis behavior is discussed in detail. From reported results, it is considered that hydrogen generation from sodium borohydride Hydrolysis is a feasible technology to supply hydrogen for the PEMFC. It has been found that the reported results are encouraging although there are some engineering problems that lie ahead. The critical issues of this hydrogen generation technology have been highlighted and discussed.
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solid sodium borohydride as a hydrogen source for fuel cells
Journal of Alloys and Compounds, 2009Co-Authors: Zhou Peng Li, S. SudaAbstract:Abstract Hydrolysis of sodium borohydride NaBH 4 is a promising method for on-board hydrogen supply for fuel cells. In this study, the Hydrolysis Reaction was studied by starting with solid NaBH 4 rather than aqueous borohydride solutions, and adding less amount of water in an attempt to explore the maximum hydrogen generation capacity. It was found that hydrogen could be liberated at very high rates and over than 90% conversion rates were achieved when the mole ratio of water to sodium borohydride was not less than 4:1. The final hydrogen generation capacity was achieved as high as 6.7 wt%. Materials such as CoCl 2 or cobalt powder were found to be effective as the catalysts for the Hydrolysis Reaction at such Reaction conditions. A large heat effect due to the exothermic Reaction and a low melting point of NaBO 2 ·4H 2 O led to the acceleration of hydrogen generation at the latter part of the Hydrolysis process. It is thus promising to utilize these Reaction conditions to achieve high hydrogen generation capacity by proper system design.
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nickel and cobalt based catalysts for hydrogen generation by Hydrolysis of borohydride
Journal of Alloys and Compounds, 2006Co-Authors: Zhou Peng Li, S. SudaAbstract:Borohydrides, a group of compounds with large hydrogen contents, can generate hydrogen readily by their Hydrolysis Reaction. In this study catalysts based on nickel and cobalt were developed to accelerate the Hydrolysis Reaction for hydrogen generation. Catalysts in four forms were tested for each metal: fine metal powder, metal salt, metal boride and Raney metal. It was found that the Hydrolysis Reaction was primary a zero-order Reaction under the catalysis of these catalysts. Although cobalt showed higher catalytic activity than nickel in most cases, Raney Ni exhibited almost the same activity as the Raney Co. Among four chemical forms for nickel, Raney Ni demonstrated the best performance. Moreover, Raney catalysts made from alloys of nickel and cobalt showed even higher activity. The Reaction on Raney metals was also characterized by a slowdown in hydrogen generation rate at low borohydride concentrations because of a mass transfer limitation.
Ping Wang - One of the best experts on this subject based on the ideXlab platform.
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effect of trapped hydrogen on the induction period of cobalt tungsten boron nickel foam catalyst in catalytic Hydrolysis Reaction of sodium borohydride
Catalysis Today, 2011Co-Authors: Hongbin Dai, Yan Liang, Ping WangAbstract:Abstract Calcination treatment is an important step in preparation of supported transition metal catalysts that are effective for promoting the Hydrolysis Reaction of sodium borohydride. We found that calcination treatment of cobalt–tungsten–boron/nickel foam catalysts results in the appearance of an induction period in their first time use, and the duration of which depends on the calcination temperature and atmosphere. Upon reusing the catalysts, the induction period completely disappeared. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and synchronous thermal analyses techniques were employed to study the mechanism underlying the induction period phenomenon. Our study results showed that the appearance/disappearance of the induction period should be correlated with the desorption/reabsorption of hydrogen in the catalysts.
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hydrogen bubbles dynamic template preparation of a porous fe co b ni foam catalyst for hydrogen generation from Hydrolysis of alkaline sodium borohydride solution
Journal of Alloys and Compounds, 2010Co-Authors: Yan Liang, Ping Wang, Hongbin DaiAbstract:By using a modified electroless plating method, a porous Fe-Co-B catalyst is prepared on Ni foam support in order to generate hydrogen from an alkaline sodium borohydride (NaBH(4)) solution. In this process, hydrogen bubbles originating from electroless deposition function as a dynamic template to form the porous catalyst. The effects of NaBH(4), NaOH concentration and Reaction temperature on the Hydrolysis Reaction kinetics are investigated. it has been found that an average hydrogen generation rate of 221 min(-1) g(-1) (Fe-Co-B) is achieved in a 15 wt.% NaBH(4) and 5 wt.% NaOH solution at 30 degrees C and the apparent activation energy of the Hydrolysis Reaction is determined to be 27 kJ mol(-1). The catalyst exhibits a high activity due to its porous structure, which facilitates the access of reactants to the surface active sites of catalyst. (C) 2009 Elsevier B.V. All rights reserved.
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high performance cobalt tungsten boron catalyst supported on ni foam for hydrogen generation from alkaline sodium borohydride solution
International Journal of Hydrogen Energy, 2008Co-Authors: Hongbin Dai, Ping Wang, Yan Liang, Xiangdong Yao, Thomas E Rufford, Huiming ChengAbstract:Low cost and catalytically effective transition metal catalysts are highly wanted in developing on-demand hydrogen generation system for practical onboard application. By using a modified electroless plating method, we have prepared a robust Co–W–B amorphous catalyst supported on Ni foam (Co–W–B/Ni foam catalyst) that is highly effective for catalyzing hydrogen generation from alkaline NaBH4 solution. It was found that the plating times, calcination temperature, NaBH4 and NaOH concentrations all exert considerable influence on the catalytic effectiveness of Co–W–B/Ni foam catalyst towards the Hydrolysis Reaction of NaBH4. Via optimizing these preparation and Reaction conditions, a hydrogen generation rate of 15 L/min g (Co–W–B) has been achieved, which is comparable to the highest level of noble metal catalyst. In consistent with the observed pronounced catalytic activity, the activation energy of the Hydrolysis Reaction using Co–W–B/Ni foam catalyst was determined to be only 29 kJ/mol. Based on the phase analysis and structural characterization results, the mechanism underlying the observed dependence of catalytic effectiveness on the calcination temperature was discussed.
Yan Liang - One of the best experts on this subject based on the ideXlab platform.
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effect of trapped hydrogen on the induction period of cobalt tungsten boron nickel foam catalyst in catalytic Hydrolysis Reaction of sodium borohydride
Catalysis Today, 2011Co-Authors: Hongbin Dai, Yan Liang, Ping WangAbstract:Abstract Calcination treatment is an important step in preparation of supported transition metal catalysts that are effective for promoting the Hydrolysis Reaction of sodium borohydride. We found that calcination treatment of cobalt–tungsten–boron/nickel foam catalysts results in the appearance of an induction period in their first time use, and the duration of which depends on the calcination temperature and atmosphere. Upon reusing the catalysts, the induction period completely disappeared. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and synchronous thermal analyses techniques were employed to study the mechanism underlying the induction period phenomenon. Our study results showed that the appearance/disappearance of the induction period should be correlated with the desorption/reabsorption of hydrogen in the catalysts.
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hydrogen bubbles dynamic template preparation of a porous fe co b ni foam catalyst for hydrogen generation from Hydrolysis of alkaline sodium borohydride solution
Journal of Alloys and Compounds, 2010Co-Authors: Yan Liang, Ping Wang, Hongbin DaiAbstract:By using a modified electroless plating method, a porous Fe-Co-B catalyst is prepared on Ni foam support in order to generate hydrogen from an alkaline sodium borohydride (NaBH(4)) solution. In this process, hydrogen bubbles originating from electroless deposition function as a dynamic template to form the porous catalyst. The effects of NaBH(4), NaOH concentration and Reaction temperature on the Hydrolysis Reaction kinetics are investigated. it has been found that an average hydrogen generation rate of 221 min(-1) g(-1) (Fe-Co-B) is achieved in a 15 wt.% NaBH(4) and 5 wt.% NaOH solution at 30 degrees C and the apparent activation energy of the Hydrolysis Reaction is determined to be 27 kJ mol(-1). The catalyst exhibits a high activity due to its porous structure, which facilitates the access of reactants to the surface active sites of catalyst. (C) 2009 Elsevier B.V. All rights reserved.
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high performance cobalt tungsten boron catalyst supported on ni foam for hydrogen generation from alkaline sodium borohydride solution
International Journal of Hydrogen Energy, 2008Co-Authors: Hongbin Dai, Ping Wang, Yan Liang, Xiangdong Yao, Thomas E Rufford, Huiming ChengAbstract:Low cost and catalytically effective transition metal catalysts are highly wanted in developing on-demand hydrogen generation system for practical onboard application. By using a modified electroless plating method, we have prepared a robust Co–W–B amorphous catalyst supported on Ni foam (Co–W–B/Ni foam catalyst) that is highly effective for catalyzing hydrogen generation from alkaline NaBH4 solution. It was found that the plating times, calcination temperature, NaBH4 and NaOH concentrations all exert considerable influence on the catalytic effectiveness of Co–W–B/Ni foam catalyst towards the Hydrolysis Reaction of NaBH4. Via optimizing these preparation and Reaction conditions, a hydrogen generation rate of 15 L/min g (Co–W–B) has been achieved, which is comparable to the highest level of noble metal catalyst. In consistent with the observed pronounced catalytic activity, the activation energy of the Hydrolysis Reaction using Co–W–B/Ni foam catalyst was determined to be only 29 kJ/mol. Based on the phase analysis and structural characterization results, the mechanism underlying the observed dependence of catalytic effectiveness on the calcination temperature was discussed.
S. Suda - One of the best experts on this subject based on the ideXlab platform.
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solid sodium borohydride as a hydrogen source for fuel cells
Journal of Alloys and Compounds, 2009Co-Authors: Zhou Peng Li, S. SudaAbstract:Abstract Hydrolysis of sodium borohydride NaBH 4 is a promising method for on-board hydrogen supply for fuel cells. In this study, the Hydrolysis Reaction was studied by starting with solid NaBH 4 rather than aqueous borohydride solutions, and adding less amount of water in an attempt to explore the maximum hydrogen generation capacity. It was found that hydrogen could be liberated at very high rates and over than 90% conversion rates were achieved when the mole ratio of water to sodium borohydride was not less than 4:1. The final hydrogen generation capacity was achieved as high as 6.7 wt%. Materials such as CoCl 2 or cobalt powder were found to be effective as the catalysts for the Hydrolysis Reaction at such Reaction conditions. A large heat effect due to the exothermic Reaction and a low melting point of NaBO 2 ·4H 2 O led to the acceleration of hydrogen generation at the latter part of the Hydrolysis process. It is thus promising to utilize these Reaction conditions to achieve high hydrogen generation capacity by proper system design.
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nickel and cobalt based catalysts for hydrogen generation by Hydrolysis of borohydride
Journal of Alloys and Compounds, 2006Co-Authors: Zhou Peng Li, S. SudaAbstract:Borohydrides, a group of compounds with large hydrogen contents, can generate hydrogen readily by their Hydrolysis Reaction. In this study catalysts based on nickel and cobalt were developed to accelerate the Hydrolysis Reaction for hydrogen generation. Catalysts in four forms were tested for each metal: fine metal powder, metal salt, metal boride and Raney metal. It was found that the Hydrolysis Reaction was primary a zero-order Reaction under the catalysis of these catalysts. Although cobalt showed higher catalytic activity than nickel in most cases, Raney Ni exhibited almost the same activity as the Raney Co. Among four chemical forms for nickel, Raney Ni demonstrated the best performance. Moreover, Raney catalysts made from alloys of nickel and cobalt showed even higher activity. The Reaction on Raney metals was also characterized by a slowdown in hydrogen generation rate at low borohydride concentrations because of a mass transfer limitation.
