Catalytic Properties of Ni3Fe Foil for Hydrogen Production from Methanol

2012 ◽  
Vol 706-709 ◽  
pp. 1052-1057 ◽  
Author(s):  
Ya Xu ◽  
Masahiko Demura ◽  
Toshiyuki Hirano ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi

The objective of this study is to investigate the catalytic properties of intermetallic Ni3Fe foil. We fabricated Ni3Fe foil of 30 µm in thickness by a metallurgical process, and examined the catalytic activity of the Ni3Fe foil for methanol decomposition from 513 to 973 K. The Ni3Fe foil showed activity for methanol decomposition above 623 K. The activity increased with the increase of reaction temperature. Surface analysis revealed that a surface structure of fine Ni-Fe particles dispersed on carbon nanofibers was formed on the foil during the reaction. The activity is attributed to the formation of this fine structure.

2011 ◽  
Vol 306-307 ◽  
pp. 130-133 ◽  
Author(s):  
Toshiyuki Hirano ◽  
Ya Xu ◽  
Masahiko Demura

This paper presents the characteristic features of the catalytic properties of the cold-rolled Ni3Al foils for methanol decomposition which were developed in our group. Methanol was effectively decomposed into H2 and CO over the foils above 713 K. The production rates of H2 and CO increased with an increase of time during the initial period of reaction, indicating that the Ni3Al foils were spontaneously activated under the reaction conditions. Surface analyses revealed that fine Ni particles dispersed on carbon nanofibers formed on the foils during the reaction. The high catalytic performance of the foils can be attributed to the spontaneous formation of this nanostructure during the reaction.


2011 ◽  
Vol 409 ◽  
pp. 307-312
Author(s):  
Junya Sakurai ◽  
Ya Xu ◽  
Masahiko Demura ◽  
Toshiyuki Hirano ◽  
Ryuji Tamura

The catalytic properties of the cold-rolled foils of intermetallic compound TiNi were studied for hydrogen production from methanol in a temperature range of 513-793 K. The catalytic activity for methanol decomposition increased with a reaction temperature, especially above 673 K. The SEM and EDS analyses revealed the formation of numerous Ni-enriched particles dispersed in the layer of carbon fibers during the reaction. The catalytic activity of TiNi foils is attributed to those Ni-enriched particles.


2007 ◽  
Vol 85 (2) ◽  
pp. 118-123 ◽  
Author(s):  
T Tsoncheva ◽  
S Vankova ◽  
O Bozhkov ◽  
D Mehandjiev

Bicomponent manganese and rhenium modified activated carbon materials, prepared by different methods, are studied and compared with the corresponding monocomponent materials as catalysts in methanol decomposition to CO and hydrogen. The best catalytic activity and stability is observed for the sample obtained by simultaneous deposition of Mn and Re precursors. The complex character of the catalytic active centre, including manganese and rhenium irons in various oxidative states, is discussed. The determining role of the Mn(II) ions in the improvement of the catalytic properties is assumed.Key words: rhenium, manganese, activated carbon, methanol decomposition.


2005 ◽  
Vol 475-479 ◽  
pp. 755-758 ◽  
Author(s):  
Ya Xu ◽  
Satoshi Kameoka ◽  
Kyosuke Kishida ◽  
Masahiko Demura ◽  
An Pong Tsai ◽  
...  

Ni3Al has attractive high temperature properties, such as high strength and good oxidation/corrosion resistance, and is possible to be used for high temperature chemical processing and manufacture. Until now, the catalytic properties of Ni3Al were rarely investigated since the leaching of aluminum from Ni3Al is difficult to obtain a porous Raney-Ni compared to NiAl3 and Ni2Al3. In the present work, the catalytic properties of Ni3Al were examined for hydrogen production reactions from methanol. It was found that alkali-leached Ni3Al showed high activity for methanol decomposition (CH3OH→ 2H2+CO). Furthermore, Ni3Al catalysts suppress the formation of methane, i.e. they show higher selectivity for the methanol decomposition reaction than Ni catalyst. These results indicate a possibility for Ni3Al used as a catalyst for hydrogen production reaction.


2006 ◽  
Vol 980 ◽  
Author(s):  
Toshiyuki Hirano

AbstractWe have successfully developed thin foils of boron-free Ni3Al (below 100 μm in thickness) by cold rolling, and recently found that the foils exhibit high catalytic activity for methanol decomposition. A little has been known about catalytic activity in Ni3Al. Even more interestingly, the high catalytic activity appears on flat foils whose surface area is very low. This paper provides a review of the characteristic features of the catalytic properties investigated in my group. Methanol was effectively decomposed into H2 and CO over the foils above 713 K. The production rates of H2 and CO increased with an increase of time during the initial period of reaction, indicating that the Ni3Al foils were spontaneously activated under the reaction conditions. Surface analyses revealed that fine Ni particles dispersed on carbon nanofibers formed on the foils during the reaction. The high catalytic performance of the foils can be attributed to the spontaneous formation of this nanostructure during the reaction.


2020 ◽  
Vol 4 (9) ◽  
pp. 4800-4806 ◽  
Author(s):  
Lvlv Ji ◽  
Huifang Zheng ◽  
Yeting Fang ◽  
Tao Wang ◽  
Jialei Du ◽  
...  

N-doped carbon nanofibers decorated with numerous ultrafine Mo2C nanoparticles show excellent catalytic activity for the hydrogen evolution reaction.


1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.


1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.


Nanoscale ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 2685-2692
Author(s):  
Isabel S. Curtis ◽  
Ryan J. Wills ◽  
Mita Dasog

High crystallinity, low oxide content, and low sintering lead to optimally performing mesoporous Si photocatalysts for solar-driven hydrogen production.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Diana García-Pérez ◽  
Maria Consuelo Alvarez-Galvan ◽  
Jose M. Campos-Martin ◽  
Jose L. G. Fierro

Catalysts based on zirconia- and alumina-supported tungsten oxides (15 wt % W) with a small loading of platinum (0.3 wt % Pt) were selected to study the influence of the reduction temperature and the nature of the support on the hydroisomerization of n-dodecane. The reduction temperature has a major influence on metal dispersion, which impacts the catalytic activity. In addition, alumina and zirconia supports show different catalytic properties (mainly acid site strength and surface area), which play an important role in the conversion. The NH3-TPD profiles indicate that the acidity in alumina-based catalysts is clearly higher than that in their zirconia counterparts; this acidity can be attributed to a stronger interaction of the WOx species with alumina. The PtW/Al catalyst was found to exhibit the best catalytic performance for the hydroisomerization of n-dodecane based on its higher acidity, which was ascribed to its larger surface area relative to that of its zirconia counterparts. The selectivity for different hydrocarbons (C7–10, C11 and i-C12) was very similar for all the catalysts studied, with branched C12 hydrocarbons being the main products obtained (~80%). The temperature of 350 °C was clearly the best reduction temperature for all the catalysts studied in a trickled-bed-mode reactor.


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