Raising the COxMethanation Activity of a Ru/γ-Al2O3Catalyst by Activated Modification of Metal-Support Interactions

Ru/Al(2)O(3)is a highly stable, but less active catalyst for methanation reactions. Herein we report an effective approach to significantly improve its performance in the methanation of CO2/H(2)mixtures. Highly active and stable Ru/gamma-Al(2)O(3)catalysts were prepared by high-temperature treatment in the reductive reaction gas.Operando/in situ spectroscopy and STEM imaging reveals that the strongly improved activity, by factors of 5 and 14 for CO and CO(2)methanation, is accompanied by a flattening of the Ru nanoparticles and the formation of highly basic hydroxylated alumina sites. We propose a modification of the metal-support interactions (MSIs) as the origin of the increased activity, caused by modification of the Al(2)O(3)surface in the reductive atmosphere and an increased thermal mobility of the Ru nanoparticles, allowing their transfer to modified surface sites.