Interaction of acetylene with the Ru(001) surface

The adsorption and decomposition of acetylene on the hexagonally close-packed Ru(001) surface has been studied by using high-resolution electron energy loss spectroscopy and thermal desorption mass spectrometry. Below 230 K, acetylene is molecularly adsorbed on this surface with rehybridization of the acetylenic carbon atoms to nearly sp3 occurring. Between 230 and 250 K, the acetylene undergoes both dehydrogenation and hydrogenation reactions, resulting in the formation of two stable surface intermediates, ethylidyne (CCH3) and acetylide (CCH). Both the ethylidyne and the acetylide decompose near 350 K, accompanied by hydrogen desorption and leaving only methylidyne (CH) and carbon adatoms on the surface. The methylidyne decomposes with hydrogen evolution into the gas phase between approximately 480 and 700 K