As a reaction of high environmental relevance, the catalytic abatement of N2O by ruthenium supported on different oxide and carbon or carbide supports was studied. Activities of Ru catalysts were determined in the presence and absence of oxygen. They were found to be significantly affected by the support material used. Ru particles on oxide supports (MgO, SiO2, CeO2, Al2O3, TiO2) were very active, with Ru/TiO2 exhibiting the best performance. The presence of oxygen in the gas feed significantly lowered reaction rates by blocking Ru surface sites. Ru catalysts supported on carbon-based carriers (activated carbon, silicon carbide) were clearly less active than their oxide counterparts. In fact, carbon and silicon carbide support materials do not act as inert structural carriers only but also as reducing agents. The oxidation of the carbon support was found to be strongly enhanced by the presence of Ru particles. Temperature programmed oxidation and reduction experiments revealed that the redox properties of the ruthenium catalysts correlate with catalytic activity and represent a key parameter for deeper understanding of the reaction mechanism. (C) 2015 Elsevier B.V. All rights reserved.