ETHYLENE ADSORPTION AND DECOMPOSITION ON (2X1) PT(110)

The adsorption and decomposition of ethylene on the (2×1) Pt(110) surface is examined with TPD and EELS. It is found that ethylene adsorption on (2×1) Pt(110) shows unique properties and is not simply a combination of the chemistry seen on the closed packed faces of platinum. The ethylene adsorbs molecularly on (2×1) Pt(110) to yield a mixture of di-σ and π-bound ethylene. Some of the adsorbed ethylene desorbs upon heating, some reacts to form ethane, and some decomposes to yield a mixture of ethylidyne (η3 ≡C-CH3), ethan-1-yl-2-ylidyne (η4 ≡CCH2-), and hydrogen. Additional hydrogen is liberated upon further heating, to produce a mixture of C2 species ([-C≡C-]x), methylidyne (η3 ≡CH), multiply bound CCH complexes, and adsorbed carbon. The chemistry on (2×1) Pt(110) is different than that occurring on other faces of platinum, which provides further evidence that the mechanism of ethylene decomposition on platinum is controlled by the symmetry of the platinum surface. © 1990 American Chemical Society.