Infrared Studies of Ethene Hydrogenation over ZrO 2

Abstract

The reaction mechanism of ethene hydrogenation over ZrO 2 was examined by in situ IR study. IR spectra of ethene, ethane and hydrogen including isotope mixture of H and D were studied. Further, the reaction of C 2H 4(a) + H 2(g) and C 2H 4(a) + D 2(g) were carried out. Consequently, it is proposed that adsorbed ethene reacts with hydrogen which is activated on the same site where ethene is adsorbed, and that the hydrogen is directly involved in the activation complex. The initial product of adsorbed ethene hydrogenation is “side-on” adsorbed ethane species which is bonded to the surface with equivalent methyl groups, and then changes to the more stable “end-on” adsorbed ethane. The mechanism, especially the manner of hydrogen activation, is discussed.