Evolution and Reactivity of Active Oxygen Species on sp2@sp3 Core-Shell Carbon for the Oxidative Dehydrogenation Reaction

Different sp2@sp3 core–shell structures are obtained on nanodiamond by using annealing treatment at increasingly higher temperatures. The resulting nanocarbons can serve as model catalysts to investigate the structural effect on the evolution and chemical nature of oxygen functional groups for oxidative dehydrogenation reactions. We studied in situ reactions and characterization data and found that the initial existence of oxygen‐containing groups on a catalyst surface had a low contribution to the catalytic performance. The active oxygen species can be generated promptly in situ by the chemisorption of O2 under the reaction conditions and involved in catalytic dehydrogenation process following a redox mechanism. For different hybridized nanostructures, the same types of generated active oxygen groups show different catalytic capabilities, which can be regulated by the sp2‐hybridized carbon fraction of nanodiamond. The ketonic carbonyl groups formed on graphitic onion‐like carbon surface are more active and can improve the selectivity to alkenes significantly compared with the initial nanodiamond and traditional carbon nanotubes. Activate your oxygen: Active oxygen groups generated in situ on defective structures play a key role in the oxidative dehydrogenation reaction. The sp2‐hybridized onion‐like carbon structure favors the generation of highly reactive oxygen species strongly.