Radiation influencing of the reactivity of NiO-Bi2O3 mixed oxides during their hydrogen reduction

✍ Scribed by M. Pospíšil; R. Klik

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 596 KB
• Volume: 47
• Category: Article
• ISSN: 0969-806X
• DOI: 10.1016/0969-806x(94)00173-h

✦ Synopsis

The basic physico-chemical properties of NiO-Bi 2 03 mixed oxides of various composition and their chemical reactivity during hydrogen reduction as a test reaction were studied. The reduction rate was found to be a nonmonotonic function of composition of the samples which can be positively affected by heat treatment in various atmospheres. Gamma-preirradiation of the system in air with a dose of 1 MGy led to an acceleration in the process of reduction, whereas irradiation of the samples in water suspension with the same dose caused a conspicuous decrease in the reduction rate. The sensitivity of the mixed oxides under study towards heat treatment and ionizing radiation, as well as their reactivity in general, decreased with increasing content of Bi 2 03 . The negative radiation effect appears to be correlable with an increase in surface oxidation ability, whereas positive influencing of the reduction rate can be correlated with an increased concentration of stabilized charge defects (non-equilibrium electrons), enhancing the reactivity of an interface.