Radiolytic preparation and catalytic properties of nanophase nickel metal particles

Nanosized nickel particles produced in aqueous sol form were prepared by ga mma radiolysis of nickel sulfate solution, using gelatin as a stabilizer. T he average size of these particles was estimated from the width of the powd er X-ray diffraction pattern to be approximately 5 nm, The magnetization me asurements were carried out from room temperature to 5 K. The ferromagnetic character of these particles was studied at 5 K. The room temperature cata lytic activity of this nickel sol was demonstrated by microcalorimetry meas urements of the heat evolved during chemisorption of hydrogen, and the reac tion of hydrogen with oxygen and ethylene at room temperature was investiga ted. (C) 2000 Elsevier Science Ltd. All rights reserved.