Effect of alkali doping on catalytic properties of alumina-supported nickel oxide in the selective oxidehydrogenation of cyclohexane

2005 ◽  
Vol 6 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Florian Patcas ◽  
Dieter Hönicke
Keyword(s):  
Nickel Oxide ◽  
Catalytic Properties ◽  
Alkali Doping

Decomposition of hydrogen peroxide on a two-component NiO-CdO catalyst and the effect of ionizing radiation on its catalytic properties

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Nickel Oxide ◽  
Catalytic Properties ◽  
Cadmium Oxide ◽  
Chemisorb Oxygen ◽  
Composition Region ◽  
Chemisorbed Oxygen ◽  
Two Component

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.

Decomposition of hydrogen peroxide on cerium dioxide-nickel oxide two-component catalysts and the effect of ionizing radiation on them

1984 ◽  
Vol 49 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Viliam Múčka
Keyword(s):  
Heat Treatment ◽  
Hydrogen Peroxide ◽  
Ionizing Radiation ◽  
Nickel Oxide ◽  
Cerium Dioxide ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Ion Pairs ◽  
Composition Region ◽  
Two Component

Some physical and catalytic properties of cerium dioxide-nickel oxide two-component catalysts have been studied over the entire composition region, employing the decomposition of hydrogen peroxide in aqueous solution as a model catalytic process. The two oxides have been found to affect each other, particularly for NiO contents of 9.1 and 96.7 mol%; the mutual influencing, the nature of which in the conditions applied remains unaffected by heat treatment of the sample or by its exposition to ionizing radiation, is manifested by the nonmonotonic dependences of the oxidation power and of the specific activity of the catalysts on their composition. This can be interpreted in terms of the concept of bivalent catalytic centres, assuming that for nickel oxide the centres consist of Ni2+-Ni3+ ion pairs, for cerium dioxide they consist of Ce3+-Ce4+ ion pairs, and that in the region of the mutual influencing , Ni2+-Ce4+ ion pairs play a major role. Within the scope of this concept, the increase in the oxidation power of all the catalysts in question and a simultaneously decrease in the specific activity of the pure nickeloxide exposed to ionizing radiation can be explained in terms of the ionization effect.

Oxygen vacancies confined in nickel oxide nanoprism arrays for promoted electrocatalytic water splitting

2020 ◽  
Vol 44 (5) ◽  
pp. 1703-1706 ◽  
Author(s):  
Xiaoshuang Zhang ◽  
Xiaoqiang Du
Keyword(s):  
Nickel Oxide ◽  
Water Splitting ◽  
Adsorption Energy ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Dft Calculation ◽  
Catalytic Properties ◽  
Calculation Results

Experimental and DFT calculation results show that the presence of oxygen vacancies can decrease the adsorption energy of intermediates at active sites and facilitate the adsorption of intermediates, thus improving the catalytic properties.

Structural and chemical disorder of cryptomelane promoted by alkali doping: Influence on catalytic properties

2012 ◽  
Vol 293 ◽  
pp. 165-174 ◽  
Author(s):  
V.P. Santos ◽  
O.S.G.P. Soares ◽  
J.J.W. Bakker ◽  
M.F.R. Pereira ◽  
J.J.M. Órfão ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Alkali Doping ◽  
Chemical Disorder
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