Catalytically Active Co−Nx Species Stabilized on Nitrogen‐doped Porous Carbon for Efficient Hydrogenation and Dehydrogenation of N‐heteroarenes

Abstract

AbstractThe development of bifunctional, highly active and stable non‐noble‐metal catalysts is important for synthetic chemistry. In this study, a highly dispersed Co catalyst stabilized on the mesoporous N‐doped carbon layers was prepared by adsorption and pyrolysis of cobalt complex on dendritic fibrous silica nanospheres (KCC‐1@Co−N−C−T). The characterizations of HAADF‐STEM, XRD and XPS together with the KSCN poisoning tests determine the absence of Co0 or CoOx nanoparticles and suggest that the Co−Nx species are the active sites. The formation of Co−Nx species results from the properties of N‐rich cobalt‐phenanthroline complex and dendritic fibrous silica supports, increasing the original spatial distance between Co atoms and thus preventing them from aggregation. The KCC‐1@Co−N−C‐800 catalyst showed excellent activity and selectivity for the oxidative dehydrogenation (ODH) of saturated N‐heterocycles and base‐free catalytic transfer hydrogenation (CTH) of unsaturated N‐heterocycles.