A model of Pt-Rh catalyst prepared by electro-chemical deposition of Rh ions on Pt(100) surface

Abstract

When Pt-Rh(100) alloy surface was exposed to NO or O2 at temperatures higher than 400 K, a characteristic p(3 × 1) LEED pattern appeared with segregation of Rh atoms on the surface. It was shown that when a Rh-deposited Pt(100) surface is heated in NO or O2 the same 5 × 10−8 Torr of H2 at room temperature, the p(3 × 1) pattern disappears but is readily recovered 5 × 10−8 Torr of H2 at room temperature, the p(3 × 1) pattern disappears but is readily recovered by exposing to O2 of 1 × 10−7 Torr at room temperature. The growth of a Rh-O overlayer on Pt layer is responsible for the formation of the p(3 × 1) structure on either the Pt-Rh(100) alloy or Pt(100) surface, and this peculiar surface may correspond to the active surface of the Pt-Rh catalyst for NOx reduction