Dynamics of Reactive Oxygen Species on Cobalt-Containing Spinel Oxides in Cyclic CO Oxidation

Reactive oxygen species (ROS) are considered to be responsible for the high catalytic activity of transition metal oxides like Co3-xFexO4 in oxidation reactions, but detailed influences catalyst composition and morphology on formation these reactive not fully understood. In presented study, Co3O4 spinels different mesostructures, i.e., particle size, crystallinity, specific surface area, characterized by powder X-ray diffraction, scanning electron microscopy, physisorption. The materials were tested CO performed consecutive runs compared a series with similar mesostructure study effects ROS formation. first run, conversion was observed dominated exposed area pure Co-spinels, while negative effect Fe content seen. following U-shaped curve which indicated situ those that new at low temperature. This activation stable higher reaction temperature confirmed after temperature-programmed (TPO). However, no run low-surface-area highly crystalline materials, lowest surface-area material even activated TPO. Among studied here, correlation small size large ability is presented, benefit nanoscaled discussed. Despite generally Fe, highest relative intermediate contents suggesting may involved