Catalytic modification in dehydrogenation properties of KSiH3

2014 ◽  
Vol 16 (47) ◽  
pp. 26163-26167 ◽  
Author(s):  
Ankur Jain ◽  
Takayuki Ichikawa ◽  
Shotaro Yamaguchi ◽  
Hiroki Miyaoka ◽  
Yoshitsugu Kojima
Keyword(s):  
Activation Energy ◽  
Hydrogen Desorption ◽  
Sorption Kinetics ◽  
Desorption Activation Energy

Hydrogen desorption activation energy of KSiH3 is reduced by mesoporous Nb2O5, which drastically enhances the sorption kinetics.

A Study on Hydrogen Desorption Properties of Multiwall Carbon Nanotubes

2005 ◽  
Vol 475-479 ◽  
pp. 2463-2468 ◽  
Author(s):  
Jai Young Lee ◽  
Ho Lee ◽  
Hyun Seok Kim
Keyword(s):  
Activation Energy ◽  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Hydrogen Desorption ◽  
Open Structure ◽  
Hydrogen Molecules ◽  
Desorption Activation Energy ◽  
Closed Structure ◽  
Oxygen Addition ◽  
Multiwall Carbon

Hydrogen desorption properties in multiwall carbon nanotubes(MWNTs) were investigated from the view points of not only physical hydrogen molecules adsorption in nano-hole but also chemical hydrogen adsorption on graphite surface. MWNTs with intrinsic closed structure having the blocked hole and MWNTs with open structure were studied through hydrogen thermal desorption technique equipped with gas chromatograph. In order to grow MWNTs with open structure, novel method using oxygen added plasma(CH4/H2/O2) has been introduced. The structure of MWNTs was gradually changed with increasing oxygen addition amount, showing aligned MWNTs bundles and open tube cap at 10% oxygen addition. The precise analysis on thermal desorption spectra on MWNTs with closed structure showed that hydrogen gas was released at three major temperature ranges such as 100-230K, 290-350K, and 600-625K, where the evolved hydrogen amounts were about 1.65wt%, 0.64wt%, and 0.03wt%, respectively. However, in case of aligned and open MWNTs, the evolution peak around 290-350K was highly developed (about 1.9wt%) and the desorption peak at 600-625K was disappeared. The hydrogen desorption activation energy was also calculated. The obtained hydrogen desorption activation energy of MWNTs with closed and open structure at ambient temperature was -18.5kJ/mol H2 and 16.5kJ/molH2, respectively. The hydrogen desorbed between 290 and 330K in MWNTs with open structure was the hydrogen physi-sorbed in nano-hole. And Ni-doping (dispersion) effect on hydrogen storage properties was investigated comparatively. Ni nano-catalysts were expected to effectively dissociate hydrogen molecules in gas phase, providing atomic hydrogen possible to form chemical bonding on carbon surface. The metal nanoparticles were homogeneously dispersed using incipient wetness impregnation method. Hydrogen desorption spectra of MWNTs with Ni nanoparticles showed that about 2.8wt% of hydrogen was released in the range of 340-520K.

Desorption activation energy distribution function of nitric oxide chemisorbed on carbonaceous materials at 373 K

Carbon ◽  
2005 ◽  
Vol 43 (7) ◽  
pp. 1445-1452 ◽  
Author(s):  
Pilar García ◽  
Alejandro Molina ◽  
Fanor Mondragón
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Distribution Function ◽  
Energy Distribution ◽  
Energy Distribution Function ◽  
Carbonaceous Materials ◽  
Desorption Activation Energy

In situ FT-IR Investigation of Formic Acid Adsorption on Reduced and Reoxidized Copper Catalysts

1994 ◽  
Vol 48 (7) ◽  
pp. 827-832 ◽  
Author(s):  
Graeme J. Millar ◽  
David Newton ◽  
Graham A. Bowmaker ◽  
Ralph P. Cooney
Keyword(s):  
Activation Energy ◽  
Formic Acid ◽  
Maximum Rate ◽  
Heterogeneous Catalysts ◽  
Copper Catalyst ◽  
Copper Catalysts ◽  
Copper Surface ◽  
Desorption Activation Energy ◽  
Ft Ir

An in situ infrared cell capable of studying reactions over heterogeneous catalysts in the temperature range 77 to 773 K has been designed. In particular, the adsorption of formic acid on a model Cu/SiO2 methanol synthesis catalyst was investigated. Exposure of a reduced copper surface to formic acid at 300 K resulted in the formation of both formic acid molecules, which were ligated to the copper catalyst, and chemisorbed bidentate copper formate species. Under temperature-programming conditions, the bidentate species displayed a maximum rate of desorption at 433 K, which correlates to a desorption activation energy of 120 kJ mol−1. In contrast, on the reoxidized catalyst, unidentate formate species were preferentially formed. These exhibited a maximum rate of desorption at a temperature of 408 K, and a desorption activation energy of 113 kJ mol−1. A mechanism was postulated to explain this behavior, and evidence was presented to show that useful kinetic data can be obtained for desorption from a catalyst in the form of a pressed disk.

Comparison of methods for deriving desorption activation energy

Vacuum ◽  
2015 ◽  
Vol 115 ◽  
pp. 58-60
Author(s):  
R. Knizikevičius
Keyword(s):  
Activation Energy ◽  
Comparison Of Methods ◽  
Desorption Activation Energy

A New Method to Determine the Activation Energy for Hydrogen Desorption from Steels

2005 ◽  
Vol 475-479 ◽  
pp. 229-232
Author(s):  
Fu Gao Wei ◽  
Kaneaki Tsuzaki ◽  
Toru Hara
Keyword(s):  
Activation Energy ◽  
Thermal Desorption ◽  
Precise Measurement ◽  
Hydrogen Desorption ◽  
New Method ◽  
Thermal Desorption Spectrum ◽  
Thermal Desorption Spectrometry ◽  
Desorption Spectrum ◽  
Tic Particle ◽  
Best Fit

A new method has been developed to determine the activation energy for hydrogen desorption from steels by means of thermal desorption spectrometry (TDS). This method directly fits the Kissinger’s reaction kinetic formula dX/dt=A(1-X)exp(-Ed/RT) to experimentally measured thermal desorption spectrum and best fit yields the activation energy (Ed) and the value of constant A. It has been proven that this new method is applicable to precise measurement of the activation energy for hydrogen desorption from incoherent TiC particle, coherent TiC precipitate, grain boundary and dislocation in 0.05C-0.20Ti-2.0Ni and 0.42C-0.30Ti steels.

Desorption activation energy of dibenzothiophene on the activated carbons modified by different metal salt solutions

2007 ◽  
Vol 132 (1-3) ◽  
pp. 233-239 ◽  
Author(s):  
Moxin Yu ◽  
Zhong Li ◽  
Qibin Xia ◽  
Hongxia Xi ◽  
Shuwen Wang
Keyword(s):  
Activation Energy ◽  
Activated Carbons ◽  
Metal Salt ◽  
Salt Solutions ◽  
Desorption Activation Energy

Effect of Na3FeF6 catalyst on the hydrogen storage properties of MgH2

2016 ◽  
Vol 45 (16) ◽  
pp. 7085-7093 ◽  
Author(s):  
N. N. Sulaiman ◽  
N. S. Mustafa ◽  
M. Ismail
Keyword(s):  
Activation Energy ◽  
Hydrogen Storage ◽  
Sorption Kinetics ◽  
Hydrogen Storage Properties ◽  
Storage Properties

The MgH2 + 10 wt% Na3FeF6 composite resulted in both a reduced dehydrogenation temperature and enhanced sorption kinetics compared to the undoped MgH2 sample. The activation energy for the decomposition of the as-milled MgH2 was 167.0 kJ mol−1 and this value decreased to 75.0 kJ mol−1 after the addition of 10 wt% Na3FeF6 (a reduction by about 92.0 kJ mol−1).

The precise deduction of desorption activation energy distributions from thermal evolution spectra

Vacuum ◽  
1984 ◽  
Vol 34 (8-9) ◽  
pp. 797-800 ◽  
Author(s):  
G Carter ◽  
P Bailey ◽  
DG Armour
Keyword(s):  
Activation Energy ◽  
Thermal Evolution ◽  
Energy Distributions ◽  
Desorption Activation Energy

Effects of pore sizes of porous silica gels on desorption activation energy of water vapour

2007 ◽  
Vol 27 (5-6) ◽  
pp. 869-876 ◽  
Author(s):  
Xin Li ◽  
Zhong Li ◽  
Qibin Xia ◽  
Hongxia Xi
Keyword(s):  
Activation Energy ◽  
Water Vapour ◽  
Porous Silica ◽  
Silica Gels ◽  
Pore Sizes ◽  
Desorption Activation Energy
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