Boosted Catalytic Hydrogenation Performance Using Isolated Co Sites Anchored on Nitrogen-Incorporated Hollow Porous Carbon

The development of a low-cost and efficient transition-metal-based heterogeneous catalyst for catalytic hydrogenation reactions is urgently desired, and yet great challenges remain. Herein, isolated cobalt single atoms incorporated within N-doped hollow porous carbon nanospheres (Co SAs/NHPCN) were successfully prepared and reported to have excellent performance on the hydrogenation of 2,3,5-trimethylbenzoquinone (TMBQ) to 2,3,5-trimethylhydroquinone (TMHQ), an important intermediate in the production of vitamin-E. It is much superior to the derived Co nanoparticles and the previously reported Co-based catalysts, ascribing to their unique hierarchically porous architecture and the atomically dispersed Co sites confirmed experimentally. The reaction mechanism was unraveled by the density functional theory calculations that the atomically dispersed CoN3–C active sites can simultaneously activate both TMBQ and H2 molecules, resulting in reasonable adsorption energies for the substrates and thus much lower reaction barrier compared to the Co(111) surface. Moreover, the developed catalyst also exhibits superior catalytic performance for the hydrogenation of various nitroaromatics to the corresponding aromatic amines under moderate conditions, implying its potentially wide applications.