The adsorption and reaction of acetylene on Pt(l11) and the p(2×2) and (√3×√3)R30°Sn/Pt(111) surface alloys were investigated with low energy electron diffraction (LEED), temperature programmed desorption (TPD), and Auger electron spectroscopy (AES). The presence of Sn atoms at the surface of the p(2×2) and (√3×√3)R30°Sn/Pt(111) surface alloys strongly suppressed the decomposition of acetylene (C2D2) to deuterium and adsorbed carbon. As a result, a new reaction path is opened on the Sn/Pt(111) surface alloys—benzene formation. Besides benzene desorption, we also observed butadiene desorption, which is obviously a C4 product of a stable intermediate in benzene production. The (√3×√3)R30°Sn/Pt(111) surface shows the highest activity and selectivity for the formation of benzene and butadiene. Following C2D2 adsorption on the Pt(111) surface at 110 K, LEED shows a faint (2×2) pattern. After saturation dosing of acetylene on the p(2×2)Sn/Pt(111) surface at 110 K we find a large increase in the (2×2) LEED pattern intensity. This implies that an acetylene (2×2) substructure also forms on the p(2×2)Sn/Pt(111) surface.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry