Ordered Porous Nitrogen-Doped Carbon Matrix with Atomically Dispersed Cobalt Sites as an Efficient Catalyst for Dehydrogenation and Transfer Hydrogenation of N-Heterocycles

Single-atom catalysts (SACs) have been explored widely as potential substitutes for homogeneous catalysts. Isolated cobalt single-atom sites were stabilized on an ordered porous nitrogen-doped carbon matrix (ISAS-Co/OPNC). ISAS-Co/OPNC is a highly efficient catalyst for acceptorless dehydrogenation of N-heterocycles to release H₂. ISAS-Co/OPNC also exhibits excellent catalytic activity for the reverse transfer hydrogenation (or hydrogenation) of N-heterocycles to store H₂, using formic acid or external hydrogen as a hydrogen source. The catalytic performance of ISAS-Co/OPNC in both reactions surpasses previously reported homogeneous and heterogeneous precious-metal catalysts. The reaction mechanisms are systematically investigated using first-principles calculations and it is suggested that the Eley–Rideal mechanism is dominant.