Synergistic Effect of N-Doped sp2 Carbon and Porous Structure in Graphene Gels toward Selective Oxidation of C-H Bond.

Abstract

N-doped carbon materials represent a type of metal-free catalyst for diverse organic synthetic reactions. However, single N-doped carbon materials perform insufficiently in the selective oxidation reaction of C-H bond compared with metal catalysts or multielement co-doped materials. There are a few reports on the application of three-dimensional (3D) carbon materials in such a reaction. Besides, the relationship between the well-developed porous structures, heteroatom doping, and their catalytic performance is unclear. In this study, 3D porous N-doped graphene aerogel catalysts with high activity and selectivity for the C-H bond oxidation under mild reaction conditions have been synthesized through a two-step method. Systematic studies on the dosage of N sources, pyrolysis temperature, and their influences on the catalytic performances have been evolved. Moreover, solid evidence of the synergistic effect of sp2 C atoms adjacent to the N atoms and porous structure promoting the performance has been provided in this work.