NEUTRON-SCATTERING STUDY OF HYDROGEN ON RUTHENIUM SULFIDE

Incoherent inelastic neutron scattering (IINS) has been used to characterize hydrogen adsorption sites on ruthenium sulfide at 300 K. Hydrogen resides on sulfur anions to form SH groups, yielding two nondegenerate bending modes at 600 and 710 cm** minus **1. A smaller feature near 370 cm** minus **1 is assigned to a hydrogen-coupled lattice mode. Complementary hydrogen adsorption and H//2-D//2 exchange data further suggest that the active sites for hydrogen adsorption may be coordinatively unsaturated S-S anion pairs which provide sufficient electron density and satisfy the dual-site requirement necessary for hydrogen adsorption.