Kinetics of reduction of nickel oxide with CO

AIChE Journal ◽  
1972 ◽  
Vol 18 (3) ◽  
pp. 506-512 ◽  
Author(s):  
J. H. Krasuk ◽  
J. M. Smith
Keyword(s):  
Nickel Oxide ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The kinetics of reduction of nickel oxide-cerium dioxide mixed systems with hydrogen and the effect of ionizing radiation on it

1984 ◽  
Vol 49 (10) ◽  
pp. 2241-2251 ◽  
Author(s):  
Milan Pospíšil ◽  
Igor Petrecký
Keyword(s):  
Nickel Oxide ◽  
Maximum Rate ◽  
Cerium Dioxide ◽  
Effect Of Temperature ◽  
Composition Region ◽  
System Composition ◽  
Radiation Induced ◽  
Kinetics Of ◽  
Mixed Systems ◽  
Kinetics Of Reduction

The reduction with hydrogen is studied thermogravimetrically over the temperature region of 260-500 °C for nickel oxide-cerium dioxide mixed systems of various composition. The overall rate of reduction increases and the maximum rate of reduction of nickel oxide decreases with increasing cerium dioxide content as a result of two counteracting processes occurring on the reaction interface and conditioned by the presence of the finely dispersed unreducible component. The dependence of the degree of reduction α on time t obeys the relation (α + 0.3)/(1 - α) = Aekt over the entire system composition region. Previous exposition of the samples to gamma does of 100 and 500 kGy from a 60Co source or to a fast neutron dose of 400 Gy from a 252Cf source results in a decrease in the rate of reduction for region with excess nickel oxide, but as the concentration of cerium dioxide is increased, inversion of the radiation-induced effect takes place and the rate of reduction becomes higher than for the initial, unexposed samples. The effect of temperature and system composition on the phenomena under study is examined and discussed.

ChemInform Abstract: Kinetics of Reduction of Nickel Oxide and Nickel Aluminate by Hydrogen.

ChemInform ◽  
2010 ◽  
Vol 26 (2) ◽  
pp. no-no
Author(s):  
S. SRIDHAR ◽  
D. SICHEN ◽  
S. SEETHARAMAN
Keyword(s):  
Nickel Oxide ◽  
Nickel Aluminate ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The Kinetics of Reduction of Dense Synthetic Nickel Oxide in H2-N2 and H2-H2O Atmospheres

2009 ◽  
Vol 40 (1) ◽  
pp. 1-16 ◽  
Author(s):  
T. Hidayat ◽  
M.A. Rhamdhani ◽  
E. Jak ◽  
P.C. Hayes
Keyword(s):  
Nickel Oxide ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The effect of origin and physico-chemical properties on the kinetics of reduction of mixed NiO-Fe2O3 oxides with hydrogen

1986 ◽  
Vol 51 (10) ◽  
pp. 2098-2108 ◽  
Author(s):  
Milan Pospíšil ◽  
Jan Topinka
Keyword(s):  
Mixed Oxides ◽  
Mutual Influence ◽  
Spinel Phase ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Preliminary Annealing ◽  
Kinetics Of ◽  
Kinetics Of Reduction

We investigated the effect of origin and some physico-chemical parameters on the kinetics of reduction with hydrogen of two series of mixed NiO-Fe2O3 oxides differing by their composition, the character of their precursors (mixed crystalline nitrates and coprecipitated hydroxides) and their decomposition temperature.This effect manifested itself by different magnitudes of specific surfaces of the mixed oxides and coherent regions of present phases as well as by different oxidizing abilities of the surface and differences in morphology and phase composition of corresponding samples in both series investigated. Nonlinear or nonmonotonous composition dependences of physico-chemical parameters investigated point to a mutual influence of individual components, which is also a function of the system origin and which modifies its reactivity during its reduction with hydrogen. The kinetics of the reduction was studied thermogravimetrically at 320-410 °C. The reduction of oxides of the hydroxide origin is catalytically accelerated by primarily reduced nickel, whereas in corresponding samples of the nitrate series, the total NiO is bound to the spinel phase and the reduction is delayed. Experimental IR spectra, the effect of preliminary annealing and DTA of the mixed oxides point to an inhibitory effect of water, which is constitutionally bound in trace admixtures of the goethite phase, on the kinetics of reduction of samples in the hydroxide series.

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