The Active State of Supported Ruthenium Oxide Nanoparticles during Carbon Dioxide Methanation
Abstract
Ruthenium catalysts supported on TiO2 have been shown to have competitive activity and selectivity for the methanation of CO2. In particular, a catalyst using preformed RuO2 nanoparticles deposited on a TiO2 support showed competitive performances in a previous study. In this work, ambient-pressure X-ray photoelectron spectroscopy was employed to determine the chemical state of this catalyst under reaction conditions. The active state of ruthenium was found to be the metallic one. Surface adsorbates were monitored in the steady state, and CHx species were found to be favored over adsorbed carbon monoxide at increasing temperatures.