The effect of doping of the ultradispersed nickel powder by pyrocarbon on oxygen adsorption and O-ads+COreaction

Oxygen adsorption and chemisorption and the kinetics of interaction between adsorbed oxygen and CO on nickel ultradispersed powder (average size of pa rticles, 20 nm) are studied. The ultradispersed nickel powder was dosed by the products of pyrolysis of chemisorbed ethylene (pyrocarbon) in the amoun t of 0.1-1.6 of a monolayer. The spectra of ferromagnetic resonance of the ultradispersed nickel powder before and after ethylene adsorption and pyrol ysis and after adsorption and chemisorption of oxygen and its reduction by hydrogen are recorded. The magnetization of ultradispersed nickel powder in creases upon dosing the surface with ethylene (C2H4ads) and pyrocarbon in t he amount of 0.5 of a monolayer. Pyrocarbon inhibits the O-ads + CO reactio n. The reaction orders with respect to O-ads and CO and the experimental ac tivation energy change. The effects of small (less than a monolayer) and la rge (more than a monolayer) amounts of the modifying agent are different.