Unveiling the OCOO Intermediate: Mechanistic Insights into Highly Efficient CO Oxidation by Au‐Based Nanoparticle Catalysts

Abstract A key intermediate on the reaction mechanism on the Au cluster is found and characterized as perester‐type species. This is essential given that by calling this intermediate by its name evidences its chemical nature and explains the high catalytic activity of gold‐based nanoparticles in the CO oxidation reaction. In contrast for Au–Ru cluster the CO oxidation reaction proceeded through oxygen dissociative adsorption in the first stage. Au 8 Ru 5 is found to be a stable bimetallic cluster in which gold transfers charge to ruthenium. The electronic state influenced O 2 activation mode, thus impacting in O 2 adsorption by dissociation. The most stable structure of both O 2 and CO adsorption over the cluster involving Ru and Au sites does not lead to the lowest oxidation barrier. Ru sites facilitated the reaction. The interface is the preferred energetically reaction site on the second oxidation stage. The oxidized phase of ruthenium in the bimetallic structure facilitated the oxidation reaction even more than the gold reference catalyst. The present study provided further insight into the origin of the synergistic effect of these metals on their catalytic activity and shed light on the nature of relevant intermediates as a guide for studying these systems in heterogeneous phase.