The UPS study of ethylene and acetylene co-adsorption with K on Ru(10(1)over-bar0) surface

The ethylene (C2H4) and acetylene (C2H2) co-adsorbed with K on Ru(10(1) ove r bar 0) surface has been studied by using ultraviolet spectroscopy( UPS). The results show that ethylene (Cz H,) is absorbed in molecular state on Ru (10(1) over bar 0 )surface stably below 200 K. The dehydrogenated of ethyle ne occurs at 200 K. The main product of the dehydrogenation of the absorbed ethylene (C2H4)is the acetylene (C2H2) After the dehydrogenation of the ab sorbed ethylene (C2H4), the binding energies of sigma (CC) and sigma (CH) b onds have an increase of 0.2 eV and 0.5 eV respectively. The acetylene is a bsorbed in molecular state on Ru(10(1) over bar 0 )surface stably at room t emperature. On a K pre-covered surface,the sigma (CC) peak disappears at ro om temperature. The element K promotes the dissociation of acetylene on Ru( 10(1) over bar 0 )surface.