The ethylene( Ct H,)adsorbed on Ru(0001)surface has been studied by using t
hermal desorption spectroscopy( TDS). The results show that ethylene (C2H4)
absorbs in molecular state on Ru(0001)surface stably below 200 K. The dehyd
rogenation of ethylene occurs st 200 K. The main product of the dehydrogena
tion of the absorbed ethylene(C2H4) is acetylene (C2H2). The Te are two ads
orption states of ethylene on the clean Ru(0001) surface. Their desorption
temperature is 275 K and 360 K respectively. The desorption temperature of
acetylene is 350 K. The desorption temperature of both acetylene and ethyle
ne rises with increasing Cs coverage.