A near-ambient-pressure XPS study on catalytic CO oxidation reaction over a Ru(10(1)over-bar0) surface

Abstract

We investigated the interactions of CO and O-2 with Ru(10 (1) over bar0) single crystal surfaces, and studied the in-situ catalytic oxidation reaction of CO on the surface under near realistic pressure conditions by using a combination of near-ambient-pressure x-ray photoelectron spectroscopy and differential pumping mass spectroscopy. At lower temperatures (T < 190 degrees C), most of the surface keeps metallic and is covered by both chemisorbed atomic oxygen and CO, and the CO2 formation rate is relatively slow. At higher temperatures, the reaction rate significantly increases and reaches the saturation, where the Ru surface is dominated by a bulk oxide (i.e. RuO2). (C) 2013 Elsevier B.V. All rights reserved.