X-ray absorption studies of the electronic structure of nickel-copper catalysts

摘要: X-ray absorption threshold resonances associated with LIII and LII edges, which are attributed to excitation of electrons from 2p core levels unoccupied d-states in the valence band, were investigated for a series nickel-copper alloys widely differing compositions. The catalysts form metal powders surface areas order 1 m2/g. When such samples determined measurements intensity emission (i.e. by so-called “electron yield” detection method), one can avoid experimental artifacts arising sample “thickness effect” encountered transmission or fluorescence measurements. Edge then be reliably powders. It was observed that copper had only small attenuating effect on nickel catalysts. smaller an magnitude than predicted rigid-band model electronic structure alloys. results provide strong support earlier conclusions others about limitations model.