Vibrational spectroscopic characterisation of hydrogen bridged between metal atoms: A model for the adsorption of hydrogen on low-index faces of tungsten

Abstract

Vibrational spectra of hydrogen chemisorbed on metal surfaces are discussed in the context of data from model cluster compounds and adsorption sites for hydrogen on low index planes of tungsten are suggested on the basis of reported electron energy loss spectra. A hydrogen adsorption site bridging two metal atoms is proposed for both the low coverage, β 2, and the high coverage, β 1, states of hydrogen on W(100) and the change in the symmetric metal-hydrogen stretching frequency is correlated with the reconstruction of the tungsten surface in the β 2 state.