The NO Chemisorption Activity of δ-FeOOH Having Different Magnetic Properties

Abstract

δ-FeOOH samples of various magnetic susceptibilities from paramagnetic to ferromagnetic region have been prepared. The correlation rate for paramagnetic NO molecules and magnetic susceptibility of the δ-FeOOH samples have been studied. In addition the electrical conductivity of the δ-FeOOH samples was measured at 303 K and various frequencies (d.c., 200–10 M Hz). The NO chemisorption rate decreases with increasing the magnetic susceptibility of δ-FeOOH. The paramagnetic δ-FeOOH of small crystallite size has the highest chemisorption rate of all FeOOH modifications. The rate-determining step in the NO chemisorption is assumed to be an electron-transfer from δ-FeOOH crystal to an NO molecule, which is governed by the magnetic ordering of spins in δ-FeOOH.